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Solar LED street light sensor node design

As solar LED street lights are widely used in urban lighting system, how to save energy and improve the street light energy utilization has become a problem urgently needs to solve. Solar LED street light involves the photovoltaic battery, LED lamp, battery, and street lamp control system, can maximum efficiency use of solar energy and prolong the service life of LED lamp holder, is now an urgent need to solve the problem. ZigBee technology with its low power consumption, reliable communications and network characteristics of large capacity for the street light automatic control domain provides a more appropriate solution [1-3].

Source the ZigBee technology and JN5139 mixed signal microcontroller, starting from the basic unit of the wireless sensor network (WSN), adopt the illuminance sensor, temperature sensor, dc voltage sensor and current sensor sampling current photovoltaic battery voltage, battery voltage, current, the LED lamp holder, such as temperature and illuminance data, design with full function based on JN5139 module equipment (FFD) of a flexible, superior performance of solar LED street light sensor nodes, for building high performance wireless sensor network to do the basic work. Combines ZigBee technology of network sensor technology, solve the problems existing in the other control methods: choose brightness sensor real-time acquisition LED lamp illumination, reduce the mistake by special environment and special time by chance, get rid of the manual intervention.

1 solar LED street lamp status, the structure of the sensor node

Sensor nodes structure as shown in figure 1, mainly including sensors, signal conditioning circuit, A/D converter, microprocessor, radio frequency communication module, positioning module and power supply module, etc. Sensor module is responsible for the monitoring area information acquisition and data transfer; Processor module is responsible for the control of the whole action of sensor nodes, data storage and processing itself and data from other nodes; Wireless communication module is responsible with other sensor nodes in wireless communication, exchange of sending and receiving data and control information; Power supply module provides the energy needed for sensor nodes.

2 the function of the sensor node

Generally the ZigBee network is composed of three kinds of nodes: coordinator, routers and end devices. The coordinator is the center of the network nodes, responsible for the network of organizations and maintenance; Router is responsible for network data frame routing; The terminal equipment is implementation specific functional unit. This design for a fully functional nodes (FFD) equipment, have the effect of routing, and is responsible for the local solar LED street lamp state parameters, such as data acquisition, which can realize the following functions:

(1) sensor nodes can regularly send monitoring sub-center of solar LED street lamp status measurement data;

(2) the sensor nodes to responding to the requirements of monitoring information, the real-time collection of solar LED street light condition data;

(3) when sensor nodes detected data more than the threshold or their energy is low, send alarm messages;

(4) can be automatic storage of solar LED street lamp status data in accordance with the time, at the same time can query of solar LED street light at a certain moment condition data;

(5) the miniaturization, low power consumption, low cost, high reliability, stability and security.

3 sensor node hardware design

Sensor node is composed of a fully functional device (FFD), its structure diagram as shown in figure 1.

3.1 the microprocessor module

As a node in a ZigBee network, low power consumption design is particularly important. After a detailed device power dissipation compared, selected JN5139 mixed signal microcontroller as the core of the processor module. JN5139 is uFl antenna is integrated in the high power module, can in the shortest possible time inner implement IEEE802.15.4 under the lowest cost or ZigBee compatible systems. The table put Jennic JN5139 wireless micro controller module used to provide a complete solution of RF and RF devices. Module provides a developing wireless sensor networks need rich peripheral devices. The module features: integration of uFl antenna slot; Compatible with 2.4 GHz, IEEE802.15.4, and ZigBee agreement; 2.7 V ~ 3.6 V voltage operation; Sleep current (including sleep timer is active) 2.8 mu A; Receiving sensitivity – 100 dBm. MCU features: 16 MHz 32 bit RISC CPU; 96 KB of RAM, 192 KB ROM; 4 input port, the 12 bit ADC, 2 11 bit DAC, two comparator, two application level timer/counter, two serial ports (one for the system on-line debugging), a SPI interface, support for 5 pieces. Able to form a robust, safe and low power wireless network applications.

3.2 sensor and regulate circuit module

Battery current and voltage detection circuit design principle diagram is shown in figure 2. Electric current detection circuit composed of hall current sensor TBC10SY and sampling resistor, level adjustment circuit, follower circuit, filter circuit, etc; Voltage detection circuit is composed of sampling circuit, follower circuit, filter circuit, etc. Need to be aware of is the charging current and discharge current of the detection circuit of current in the opposite direction, need through the boost voltage circuit converts load voltage is positive, and dealt with in the program.

Photovoltaic cell current and voltage detection circuit design principle diagram as shown in figure 3 [4]. The photovoltaic battery power series precision small resistance of the circuit of signal as a current detecting signal, USES the integrated operational amplifier ICL7650 differential amplifier circuit, so that we can minimize the impact on the circuit being measured. On a big resistance voltage divider will be folded into a photovoltaic cell to obtain small signal as a voltage signal, also adopts integrated op-amp ICL7650 make differential amplifier circuit. In order to eliminate interference, using two equivalent resistance respectively in two amplifier input and in between, at the same time the amplifier output increase filter circuit, after filtering, the current and voltage signal output to the A/D conversion interface controller JN5139.

LED lamp illumination detection circuit as shown in figure 4. Intensity of illumination detection using On9658 integrated sensor, sensor to obtain the signal after amplifier amplification and filtering the output to the controller after the A/D conversion interface JN5139.

LED lamp holder temperature detection circuit as shown in figure 5. Battery temperature adopts the integrated temperature sensor SHT11.

4 sensor node software design

4.1 the overall design of the software system

The main functions of the software system includes the sensor data acquisition and processing, wireless transceiver and the node positioning, using modular design. Sensor data acquisition and processing module mainly set the battery status signal sampling parameters and control; Wireless transceiver module by setting registers, control of command or a data receiving and sending; Node positioning module for real-time positioning nodes. Sensor node design for a fully functional devices (FFD), has a routing functions at the same time, the program flow chart is shown in figure 6. In the task are added into the task queue for data acquisition, alarm, detection and energy detection and call the ZigBee send task; Produce JN5139 pin is interrupted, the CPU turns to execute the ZigBee receiving interrupt service routine. If collect command is executed immediately data acquisition and sending; Immediate execution, if it is a routing packet routing updates.

4.2 design of node localization algorithm [5]

Node indicator based on the received signal strength positioning algorithm to realize accurate positioning. Known to launch the node’s signal strength, the receiving node according to the strength of the received signal to calculate the signal propagation loss, then according to the signal propagation model formula will propagation loss into distance, reuse the trilateral measurement method to calculate the unknown node location. In actual positioning, to ensure that the unknown node is in three or more emission signal intensity and position coordinates of known reference node of communication within the scope of unknown node according to the received signal strength to calculate the signal propagation loss, and then calculate the node position.

Based on wireless sensor network are introduced in this state of high precision solar LED street lamp design of sensor nodes, in the actual testing process, the system runs stably, the measured results accord with actual, completely achieved the collection and wireless transmission of signal with high precision, good monitoring effect is obtained. The system combined with wireless sensor network with low power consumption, low cost and node many advantages, such as in remote wireless communication technology, high reliability, the application will be more and more widely in the process of problem solving.

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Used for general illumination LED drive scheme of medium voltage

Many secondary voltage LED application are using off-line AC – DC power supply, battery or low voltage AC output of the electronic transformer power supply. But some of this power supply, such as lead-acid battery, only after a simple voltage regulator. Therefore, we need to have a can work in the wide input voltage range, and can use all topology configuration of the LED driver solution, to support the LED load requirements. According to the current and working conditions, LED can use linear or switch voltage regulator LED driver solution. Ansion beauty for medium voltage LED semiconductor application offers a variety of topological structure of the solution, can meet the landscape lighting, low voltage track light, solar lighting, automotive lighting, emergency vehicle lighting, Marine lighting, 12 Vac/Vdc MR16 lamp sign, aircraft interior lighting, backlighting, billboards text circuit and logo, etc all kinds of general lighting needs.
General topology structure and medium voltage LED power supply

Medium voltage drive scheme of LED lighting applications need optimization. Ansion beauty semiconductor provides inductance type, charge pump type, linear three different topology of medium voltage LED driver solution, can meet the application requirements of different users, as shown in figure 1.

Medium voltage power supply there are several kinds of LED applications, each have its main use. Among them, the off-line AC voltage adapter, common voltage for 12, 24, 36, 48 Vdc, voltage regulation accuracy of + / – 5%, suitable for security requirements is not high low to medium power applications. Sealed lead acid battery, only after a simple voltage regulator, 8 to 14 Vdc, widely used in auto lighting; 7-27 Vdc, used in automotive, solar, Marine lighting. 12 Vdc and 12 Vac power source, commonly found in indoor lighting, track lights, outdoor lighting, landscape lighting, etc.

1) the linear LED driver solution

Linear solution is the first choice for many lighting applications, because its design is simple, and intuitive, and allow the use precision, steady flow of current to drive the LED input without having to consider the LED forward voltage or power how to change.

Because this kind of LED driver is linear, the application must match the power requirements. Ansion beauty semiconductor provides current 1 A from 10 mA until all kinds of linear constant current LED driver. Channel output current is 10 to 50 mA NSI50010Y, NSI45020JZ, NSI45020, NSI45020A, NSI45025, NSI45025A, NSI45025AZ, NSI45025Z, NSI45030, NSI45030A, NSI45030AZ, NSI45030Z, NSIC2020B, NSIC2030B, NSIC2050B and NCV7680; 60 to 350 mA have NSI45060JD NUD4011 NSI45090JD and CAT4104; And the output current more channel NUD4001 (500 mA) and CAT4101 (1000 mA).

In a linear constant current current stabilizer NSI45 series as an example, this is double side or three side of linear constant current current stabilizer, based on various semiconductor pending patent since the bias of the transistor technology, very suitable for different input voltage LED widespread application, such as drive building, automotive and industrial sign the current LED lighting application. It can work in a wide input voltage range for the engineer to provide suitable for their application of simple, cost-effective steady flow scheme, and without sacrificing performance. The constant current current stabilizer series can be steady flow in a wide scope, ensure that the work voltage range of constant brightness, and has a negative temperature coefficient feature, voltage and working temperature in extreme protect leds from thermal runaway (thermal runaway).

NSI45 another typical application is used to display text and billboards circuit of constant current linear LED drive current stabilizer. Its features include low trigger voltage, regardless of the forward voltage (Vf) can achieve precise steady flow, how to change negative temperature coefficient characteristics, can protect the leds.

2) the LED MR16 bulb solution

NCL30100 is a buck LED drive controller with energy-efficient adaptive fixed closing time, peak current control, can be used for space and efficient vital restricted the application of low power and space. This scheme has the oscillation frequency adjustable characteristics, adopting the continuous conduction mode (CCM), can save the output capacitor, energy efficiency is as high as 95%, and to provide LED open-circuit protection of nature.

The drive controller switching frequency up to 700 KHZ, do not need to output capacitance, Vcc work ranges from 6.35 to 18 V, can drive one or more of the high power LED, mainly used in the MR16 LED lighting, HuanJingDeng lighting, traffic lighting, outdoor lighting and solar LED, LED light bar, etc. Using NCL30100 PCB is very small, can be loaded into the MR16 lamp holder. NCL30160 hysteresis control feature can provide fast during load transient response, no small signal control loop compensation components. Protective properties including available resistance setting the LED current, LED a short circuit protection, under voltage lockout and thermal shut down.

Use NCL30100 available negative flu test, with a small inductance reduces power loss and achieve low cost, energy efficient and less number of components used. The device adopts the low side N – FET switch topology, as well as the continuous conduction mode operation, do not need to output capacitance. Therefore, adopting various semiconductor provides the assessment board and NCL30100ADLMGEVB NCL30100ASLDGEVB circuit can be in the MR16 lamp holder, which can realize PWM dimming.

In addition, the LED module for three to four of the 12 V AC – DC design, can use various semiconductor for NCP3065 NCP3065BBGEVB evaluation board. It can be used to drive 12 Vdc/Vac application of sharp ZENIGATA, Cree XLampMC – E and other LED module. Due to the module positive voltage and input voltage range overlap, so only use a switch buck – boost type configuration. Is characterized by small size, wide input and output voltage, output current through the steady flow, but also has LED open-circuit protection, output short circuit protection. The solution is suitable for the MR16 lamp, landscape lighting, traffic lighting, etc.

3) solar powered LED street solution

NCL30160 is a switching voltage regulator for high power leds, based on NCL30051 power provided by the constant voltage to lower voltage, so as to provide constant current for the LED string. Through the use of only 30 m Ω low conduction resistance of mosfets and ability to work with 100% duty cycle, can provide energy efficiency up to 98% of the solution.

The device to 40 V to 6.3 V input voltage range of the work, switch frequency is up to 1.4 MHz, industrial and automotive applications is an excellent solution. High switching frequency make designers can use smaller external components, to help minimize circuit board size and the cost to a minimum. NCL30160 contain hysteresis control characteristic, provide fast during load transient response, no small signal control loop compensation components. Protective properties including available resistance setting the LED current, LED a short circuit protection, under voltage lockout and thermal shut down. In addition to a dedicated PWM dimming pin/low power shut down function.

NCL30051 work with NCP30160IC collocation, can be minimal external components to simplify the power circuit design. This architecture enables chipset integration in a more compact and higher cost performance LED lighting power supplies, used for outdoor lighting, such as LED street, street lamp, parking lamp), etc. General lighting applications.

To promote LED replace incandescent lamp

According to the national development and reform commission and other departments jointly issued by the “about getting banned import and sales of general lighting incandescent announcement, October 1, 2012, will be in accordance with the power of phased gradually banned the import and sale of ordinary incandescent lighting. Ansion beauty using power management semiconductor, energy efficient power supply and encapsulation of the core specialty and advantages, the development of dedicated LED drive, according to different applications and meet or surpass specification requires that solid-state lighting solutions around the world, for the realization of the lighting revolution provides the rich choice, and will play an actively promoting role in the process.

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Different LED backlight or flash application of low voltage drive scheme selection

For low voltage portable devices backlight or flash applications to choose the appropriate light emitting diode (LED) driver program is a challenge for the designers, because both must consider to extend battery life, and to reduce the printed circuit board (PCB) area and height. At present, the small liquid crystal display (LCD) panel and keyboard backlight and indicator application USES mostly white LED and RGB trichromatic leds; In the mobile phone and digital camera flash usually use high brightness LED light source. Therefore, these applications need to optimize the drive solutions, using low voltage portable LED driver topologies.

Ansion beauty as a global semiconductor energy-efficient electronics first high-performance silicon solution provider, to provide cover inductance type, charge pump type, linear different topology structure, such as low voltage portable devices backlight or flash. These solutions, the inductance type scheme can provide the best overall efficiency, the charge pump type scheme using low altitude ceramic capacitor as energy transfer mechanism, occupies board area and height of the tiny, linear drive scheme is choice of color indicator, and simple backlighting applications. These solutions can be used to meet different application requirements.

1) type inductor step-up and step-down scheme

In terms of step-up inductor type topological structure, various semiconductor using PWM and/or single call the different methods of optical products, suitable for low voltage portable device to drive the white LED backlight and flash applications. These products include: output current for 20 mA CAT37 CAT32, CAT4238, CAT4252, CAT4253 CAT4157 CAT4158 and CAT4258, output current for 40 mA CAT4137 and NCP5005, output current is 50 mA CAT4139, and larger output current CAT4240 (250 mA), NCP1422 (800 mA) and CAT4131 (1.5 1.5 A/A), etc.

NCP5005, for example, it is a compact high efficiency backlight LED booster drive, providing up to 22 V voltage, for LCD backlight control, keyboard backlight applications between two and five series of white LED power supply. Its efficiency is as high as 90%, shutdown current 1 mu A, the work input voltage range of 2.7 V to 5.5 V. Its built-in short circuit and over voltage protection and functions of undervoltage cut-off. Its current can automatically match LCD, all the pins for the ESD protection, low EMI radiation.

In inductive step-down type topology structure scheme, manufacturing semiconductor provides the output current up to 1 A NCP1529 white LED drive, used in A flashlight/flash applications.

2) a charge pump type

Ansion beauty four modules (Quad – Mode) of semiconductor patent adaptive fractional charge pump can effect comparing the market higher than that of conventional three mould charge pump provides 10%, and reduce the size of up to 65% of the packaging, will be the performance of the LED drive to new levels. Quad – Mode LED drive usually can provide energy efficient LED driver based on inductance, while eliminating the inductance of the thicker and harmful EMI interference.

Most charge pump LED driver can provide corresponding to the output voltage and input voltage ratio of the three operating modes: 1 times, 1.5 times and 2 times; Four mould structure has increased 1.33 times of the fourth kind of operating mode, requires no additional capacitance and inductance. Than the three model charge pump efficiency increased by more than 10%.

Ansion beauty semiconductor provides total output current of 10 mA, 192 mA, a variety of products, covering NCP1840, CAT3661, NCP5612, CAT3647, CAT3200, CAT3200H, CAT3606, CAT3616, CAT3626, CAT3636, CAT3637, CAT3649, CAT3604A, CAT3604V, CAT3614, CAT3644, CAT3648, and CAT3643 NCP5623B/C; Has a larger output current NCP5603 of product (200 mA 200 mA DC, pulse), CAT3612 (300 mA) and CAT3224 (4 flash, 400 mA torch), etc.

NCP1840 multi-channel LED drive, for example, the device can help the user to create any lighting graphics, as many as eight independent drive leds. Because the processor is no longer need to directly control each independent leds, adopt NCP1840 can simplify is usually performed by the processor in the system design of the work; Through a unified control the LED brightness and blink rate, serial interface to write or read registers, can carry on the current and the dimming level programming conveniently. LED brightness degree can be in the form of logarithm and nonlinear control, so that the watch no brightness distortion to the naked eye. NCP1840 four mould charge pump adopts high efficiency, low noise, can extend the battery life, very suitable for portable applications.

3) linear drive solutions

Ansion beauty semiconductor provides much money 2 to 4 channel single-mode linear backlit LED drive, such as CAT4002A, CAT4002B CAT4003B CAT4004A and CAT4004B, etc. The backlight driver EZDim interface provided by 1 line 32 dimming control, has 25 mA (type B) fixed or adjustable (type A) very low output current and lower than 1 mu A shut off the current, without switching power supply noise problem.

The single-mode LED drive usually as part of the system level way, simple to design integrated low voltage LED and LED backlight circuit of the drive. These USES thin micro encapsulation drive circuit is simple, can extend the battery life, reduce the cost, such as eliminating external capacitors) and lower noise, for entry-level portable products, such as mobile phones, cameras and video cameras, portable games, and a portable medical device market provides a simple solution.

4) special camera flash LED driver solution

Leds are increasingly used in camera phones, smart phones, and xenon bulb replacement, and provide ongoing light output capacity, so as to meet higher performance requirements. Ansion beauty semiconductor CAT3612 CAT4131 CAT4134 and CAT3224 are such drive solutions. These devices inductance, charge pump and booster topology structure, can provide different flash current and brightness.

CAT4134, for example, it is a high power inductor step-up type dual channel drive converter, provides a two-way matching the LED current. Output current levels through one of two resistors RSET or RFLASH to control. When FLASH input pin for low pattern (film), resistance RFLASH set the LED current. Each channel drive 2 or 3 white leds in series, and provide an electric current to control the brightness can be adjusted. Support the low input voltage to 3 v, making the device is suitable for lithium ion battery applications.

High frequency low noise operation make the device can be used with small external inductance and ceramic capacitors, providing excellent energy efficiency at the same time. When the device when not in use, can be shut off the pin sets the device to “zero” static model. CAT4134 besides has the soft start and current limit function, but also has thermal shut down protection function. (OVP) allows the user to limit overvoltage dedicated pin LED power supply voltage.

Charge pump type drive CAT3224 also suitable for camera flash applications, which support high megapixels camera flash, and replace the xenon flash, with synthetic fiber thin design. CAT3224 is the industry’s first 4 A single chip, the super capacitor LED drive, integrates dual mode (1 x / 2 x charge pump, provides three key functions: precision of super capacitor charge and discharge current to the LED flash of the management, as well as the LED flashlight provides constant current mode. These three models of working current are all can be simple and easy programming, 3 external resistance provide LED flash pulse currents of up to 4 A. Ultracapacitors peak current advantages, combined with CAT3224 simple parallel logical interface, so that the device is very suitable for using LED alternative applications of xenon lamp.

5) multifunctional and RGB drive

Ansion beauty semiconductor also provide all kinds of multi-functional LED driver (such as LV5219LG LV5231CS LV5207LP and LV5216CS) and RGB lighting drive (such as LV5213LP, LV5217LP LV5223GR LV5226CS and LV5230LG), the former has the LED current programmable, main brightness LED automatic brightness control and external control, and other functions, suitable for 7 to 16 channel LED flashlight/torch, RGB lighting, the main LCD backlight, auxiliary various applications such as LCD backlight. The latter is mainly used to support color lighting design, to achieve portable equipment lighting colour.

summary

As applied to primary high-performance green electronic products, energy efficient silicon solutions suppliers, manufacturing semiconductor use in low voltage and high voltage technology and expertise in power management solutions, to provide comprehensive LED driver or control solutions, including applied to portable devices backlight rich LED drive or flash applications. These solutions in the integration of more features at the same time, using smaller and smaller encapsulation, achieve more and low power consumption, help the engineering team and the original equipment manufacturer (OEM) products cost-effective use of LED lighting to reflect different, and faster time to market.

– — – — – — – — – — – — – — – — – — the buyer

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Discussion on the LED open circuit protector protective effect

High power LED is increasingly applied to the traffic light, luminous kanban, street lamps, airport runway, railway crossings, medical/surgical lighting, and driving signal. Their long service life, high power white LED usually have 35000 to 50000 hours of life), low power consumption. But, LED by overvoltage caused by lightning strike, electrostatic discharge (ESD), overheating, even damage power reverse connect.

Because LED lamp series, usually in series if the lamp string an LED open-circuit because of malfunction, list all of the LED will go out. LittELfuse provides LED open circuit protector. Protector can with lamp series each of the leds in parallel, it can bypass open-circuit fault LED, to keep the lamp string the rest continue to work. When over voltage circuit and may result in lamp string over current occurs, or when electrode after the protector will also.

When there is open circuit fault, an LED LED open circuit protector will start conduction, limit the voltage to 1.3 V, and keep the rest continue to work in tandem.

Designers to do this, tried many devices, such as the zener diode, metal oxide varistor and silicon controlled rectifier, but are not as good as LED open circuit protector, because LED open circuit protector is designed specifically for this application. As shown in figure 1, when there is open circuit fault, an LED LED open circuit protector and feel that the voltage rise, and start conduction, limiting its pressure drop to around 1.3 V, in order to keep the rest of the LED twinkle light work properly.

Leds open circuit protector has different characteristics and rated voltage are optional. Some protector is designed to protect the LED twinkle light of a single LED; Other allows designers to use a single device to protect two, three, four or five leds, to save costs. Littelfuse open circuit protector is a new generation of LED, can provide the ESD protection at the same time.

ESD and lightning protection

ESD during assembly or installation can enter to the LED lamp string. Lightning can be two ways to enter the LED lamp string: nearby lightning may cause transient in the power supply, can be coupled to the LED driver and into the lamp series; Or near lightning can on LED drive power supply rail, may also after receiving of LED lamp string on a line causes electrical transients.

Open circuit protector is a new generation of LED, such as the Littlefuse PLED series 5, can handle in + / – 15 kv air discharge, plus or minus 8 kv contact discharge of ESD events, as well as EFT events of 5/50 + 40 a ns (rapid bursts).

Polarity reverse connect protection

When a LED lamp string containing PLED5 is reverse on the power, all protector will start conduction, will be to protect the LED on the current shunt in order to protect them from harm. After reverse electrodes are correct, the protector will shut down, the LED to work normally.

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The realization of the LED dimmer

LED dimmer can further improve the LED energy saving effect, and LED the silicon controlled dimmer is easy to implement and easy to use and a series of advantages, introduce below LED SCR dimmer control working principle, characteristics and application of related problems that should pay attention to.

Tags: LED dimming phased dimmer surge current peak voltage

1, LED the market and technology progress

Because incandescent light-emitting efficiency is low, so governments around the world have made the schedule as shown in figure 1 out incandescent light bulb, and LED high luminous efficiency and long working life a series of advantages of the LED lighting has been widely used, and performance of the LED luminous efficiency improve, progress LED related technical indicators as shown in table 1.

2 lighting dimmer

Move light has the advantages of energy saving lighting dimmer in the application has a very good market, relative to incandescent lamp/gas discharge lamp, LED dimming energy-saving effect is more obvious. Incandescent lamp/gas discharge lamp dimming lights at work efficiency has declined obviously, and that move light LED luminous efficiency will improve, this is mainly due to the low luminescence brightness forward current through the LED when small, on the cause of the ingredients on the loop resistance losses. Not only energy saving lighting dimmer, lighting dimmer can change space visual effect, so as to affect the person’s behavior patterns.

But, LED dimming circuit design for LED dimming performance have very important influence. High-performance dimmers are welcomed by the users, LED SCR dimmer related problems are discussed below.

2.1 the LED dimmer

LED due to specific good in color, the luminescence efficiency, small volume, low working voltage and long life advantages obtained the very good application, however, the standardization of dimming control is very important for the promotion of LED dimmer application. Because incandescent silicon controlled dimmer got very good application, LED dimming with thyristor adjustable light very well, to utilize the existing incandescent SCR dimmers.

LED is used to substitute common incandescent lamp lighting, LED light and LED luminous color, LED, LED the luminous efficiency of light output (such as dimming curve) factors; Dimming control methods (such as 0-10 v, DALI and related control protocol (TCP), thermal management, drive solutions, topology and existing infrastructure on the working state of the LED dimmer and dimmer control performance has a great influence.

2.2 the LED dimming performance

Because people are used to the incandescent light bulb SCR dimmer, so the LED dimmer should be compatible with silicon controlled dimmer, and should consider the following technical indicators:

(1) the dimming range

Maximum brightness value as a percentage of the dimming range of commonly used expression, for example – X % XX %. In the practical, with

Lamp luminous brightness reduce human eye the pupil magnifies, that the human eye receives the light is not very soon and decreased with the decreasing of light intensity, such as expressed as the percentage of its maximum brightness level, is the human eye receives in the root mean square value of the light is measured as the percentage of light. Measured the dimming level, for example, 10% of the maximum luminescence, the human eye receives the light

The maximum luminescence, the so-called psychological laws of physics.

(2) in the whole range should be smooth, adjustable light changes.

(3) the lamp in the lowest photoelectric normally start the lamp luminous glow should be fast to the expected value.

(4) to the expected after the dimming level of the LED light should be stable, there should be no light flashing phenomenon.

(5) within the scope of the whole dimmer, LED lamp, LED driver power supply and dimmer controller should be no audible noise.

(6) motion control/have no detection/photoelectric detection component can control LED lights work.

2.3 work reliability
Dimmer for most of the light source, can extend its service life, because under low light intensity of the lamp power consumption is reduced, and the fever is helpful to improve the service life of the light source.

Temperature has important effect on the life of electronic components, low temperature is helpful to prolong the life of electronic components, LED light for light and electronic components of the integration of light, so the whole lamp life of electronic components by the life of the shortest life constraints, dimming is beneficial to lower the temperature of the LED lights, is conducive to the luminous flux LED lights to maintain rate and prolong the service life of LED lights.

Three phased dimmer

Phased dimming the earliest used in incandescent lamp dimming, main advantage of phased dimming is used, easy installation. LED phased dimming, frequency shall be not less than 100 hz, in order to avoid the human feel light flashing, phase KongDao flux Angle, the greater the luminous intensity of leds, the greater the phased semiconductor devices available SCR, fet, or related to semiconductor devices.

Because of the existing dimmers is designed for incandescent lamp (approximate resistance load, power mostly between 20 w and 50 w), so some additional circuit is needed to allow them for LED lighting system. At present, the market there is no standard in incandescent lamp dimmers on, so there are a lot of different performance and parameter values on the market at present the dimmers.

3.1 front phased dimmer

Frontier phased dimming light (before) because of its simple circuit to realize so widely used, switching devices commonly used thyristor, by controlling the conduction Angle of thyristor to control the output alternating current effective value, so as to achieve the dimming control, typical forefront of thyristor phase control the dimming circuit principle diagram is shown in figure 2. VR4 in figure 2, adjustable resistance and capacitance C23 phase shift circuit. When the voltage at the ends of the C23 reach or exceed the DIAC (DB3) breakdown voltage, charge by DB3 C23 part into bidirectional thyristor T2, bidirectional thyristor triggered T2 conduction.

Two-way thyristor the minimum gate trigger current T2 (IGT) two-way thyristor conduction. It also requires a minimum of maintenance to maintain the bidirectional thyristor conduction current, when current below the holding current, the bidirectional thyristor T2 is closed. SCR frontier phased move light dimming waveform diagram as shown in figure 3, the frontier facies dimming control is often used in incandescent and halogen tungsten lamp dimming applications, due to the low brightness by thyristor current is reduced, such as adjustable brightness is low, through the thyristor current is lower than the SCR to maintain current flow can no longer move light, otherwise the thyristor turn off, the low brightness of LED dimmer can be a problem.

4 evaluating thyristor phased LED adjustable optical-intensity system related problems that should pay attention to

Common thyristor phased evaluation LED adjustable optical-intensity system related problems that should pay attention to the following.

Light output is 4.1 100%

When the position of dimmers adjust to 100% and an adjustable light output time output attenuation?

4.2 the major light level

Adjustable light LED lighting system, is the most major light level? 4.3 physical adjustment range and light dimmer output characteristic

(1) the dimmers physical adjustment range is how much? Corresponding LED dimming range is how much?

(2) before the cut off dimmer, in a low light output adjustment range adjustable light output invariable physical adjustment range is how much?

(3) adjust the position, light dimmers physical output and added to the LED lamp on the load voltage RMS (phase Angle, conduction time and duty cycle, etc.) have a relationship?

4.4 dimmers adjustable LED light quantity range/minimum load

(1) the dimmers can be dimmable LED load normal number range is how much?

Incandescent light bulbs, (2) silicon controlled dimmer can take minimum load and maintain current of thyristor, the lowest LED adjustable brightness leds when the minimum working current required to maintain current SCR?

4.5 the surge current

For incandescent lamp silicon controlled dimmer, its input current and surge incandescent filament of cold resistance is related to the LED dimmer load when the thyristor surge input current value than incandescent dimmer, in order to ensure thyristor dimmer circuit and reliable work.

4.6 repeat peak voltage

Withstand voltage value of SCR is limited, should ensure that the LED application when using thyristor repetitive peak voltage is lower than incandescent dimmers repetitive peak voltage, to ensure that the silicon controlled dimmer circuit and reliable work.

4.7 the most minor light range

In silicon controlled dimmer lowest position that move light LED are conduction.

4.8 LED light dimmer

In practical, the silicon controlled dimmer from maximum to minimum, or from least to most major light there is probably somewhere in the middle of the dimmers LED does not work, the LED SCR dimmers have this phenomenon?

4.9 conduction delay time

(1) the LED SCR dimmers maximum conduction delay time is how many?

(2) LED SCR dimmers conduction delay in dimmer what position?

(3) conduction delay and the dimming level about?

(4) when the different LED products connected to the LED SCR dimmers in the conduction delay time change? Whether the dimmer will produce the dimming “popcorn” effect (adjustable light output flashing)?

4.10 move light flashing

In LED SCR dimmers adjust light if there is a light flashing? In LED SCR dimmers adjust light stroboscopic effect?

4.11 change color

In LED SCR dimmers adjust if there is any color change LED light? If there is any color change?

4.12 the audible noise

LED SCR dimmers are audible noise when the dimmer? LED SCR dimmers adjust light whether the advent of audible noise and some factors (for example, LED SCR dimmers with the number of LED lights and LED SCR dimmer light position and other factors)?

5 subtotal

Because silicon controlled dimmer is easy to use, in line with people’s habits, so to promote LED SCR dimmer has very good market prospect. LED dimming applications, however, the silicon controlled dimmer in the power factor of the circuit, adjustable light flashing dimming performance and cost aspects still need to further efforts, in order to expand the SCR dimmer in the LED lighting application range of the dimmer.

In this paper from the light fixtures

Posted by admin in led and tagged with The realization of the LED dimmer

Leather wastewater treatment technology

Large wholesale products field of sewage treatment plant is processing leather sewage plants, design processing capacity of 9700 m3 / d, SRL is an exclusive use, average daily processing leather sewage water volume 1500-3000 m3. According to QingZhuo leather-making sewage diversion, separation treatment principle, the preprocessing of sulfur containing chromium containing wastewater separately collected comprehensive wastewater by biological and chemical treatment technology is carried out
Principle, and then discharged into urban sewage. Perform “Shanghai integrated wastewater discharge standard” (DB3199-1997)

Sewage treatment process
The pretreatment of high concentration of chromium containing wastewater separate collection, alkaline precipitation recycling; The waste water with high sulphur content will be separate collection,
Catalytic oxidation desulphurization process. Comprehensive control of other tanning wastewater (including sewage) after pretreatment by comprehensive pipeline to bio – chemical secondary treatment in wastewater treatment plant. Primary processing integrated wastewater by fine grille, aerated grit chamber, adjusting pool and pool, balance water, remove large particles inorganic, part of the COD and BOD. Secondary treatment namely, biological treatment, the traditional activated sludge process, the piston flow reactor, drum wind aeration at this stage maximum degradation of pollutants in wastewater and removal.
Chemical processing the sewage into the pool chemicals for chemical coagulation precipitation, coagulant using basic aluminium chloride, inclined tube sedimentation. SS and COD in wastewater has been further reduced. Sludge treatment sink at the beginning of the sewage treatment process of sludge, sludge and chemical sludge concentration pool, after gravity concentration, sludge conditioning, enter the plate and frame filter press filter dewatering, returned to the sewage treatment system, the filtrate cake sinotrans central treatment by the local environmental protection department.
The processing of main monomer
2.1 pretreatment
2.1.1 sulfur-containing wastewater oxidation desulfurization
Special pipe separate collection, coarse and fine chrome bar two filtering; Manganese sulfate catalyst, additive concentration, 40-80 – g/kgNa2S before aeration and aeration respectively 2 hours after dosing twice; Table of forced oxygen filling machine, 20 mm impeller submersion depth, lead acetate dipstick test desulphurization effect, sulfide removal rate 95% or higher; Will try tanning ammonium deliming softening in sulfur-containing wastewater, in the process of oxidation desulfurization, have a function in addition to ammonia, NH3 – N removal rate is about 30%; Remove bottom mud regularly, ensure the treatment effect.
2.1.2 precipitation of chromium-containing waste water recycling
Special pipe separate collection, grille, double filter cloth filter; Adding 35% sodium hydroxide, controlling reaction pH7-8, compressed air mixed stirring, continuous reaction 15 to 30 minutes; Plate and frame filter, chromium mud solids content about 20%, 7-20% chromium content; Chromium removal rate > 99.5%.
2.2 the primary processing
Rotating the large particle of solid fine screen intercept wastewater, hair, skin, rotten meat, etc; Aerated grit chamber perforated tube evenly aeration and settling to remove sewage medium sand and gravel small particulate matter; Adjust pool aeration stirring for 24 hours, balance water, according to the average daily water to determine the adjusting pool for water level lower limit, according to the liquid level height adjust volume, qing pool regularly, dredge air perforated pipe, guarantee the air flow; Advection pond, at the beginning of mechanical scraping mud, mud gravity centrifugal pump mechanical dredge, according to the daily sewage quantity determine the pond, water flow, according to the nature of carbon sludge such as thickness, smell and so on to determine the number of mud and time;
Primary treatment effect

Posted by admin in Environmental protection equipment and tagged with Leather wastewater treatment technology

Of potassium, combined humic acid organic fertilizer patent technology

Our country is an agricultural big country, in recent years as the production of agricultural crops, according to estimates the by-product of crops straw each year about 600 million tons, which can be collected using the resources of about 480 million tons. Of these crops straw is rich in nitrogen, phosphorus, potassium and trace elements such as composition, is a development to the value of the huge amount of resources comprehensive utilization. In terms of straw industrial raw materials, paper industry used more in most of the areas in China such as straw, wheat straw, reed, bagasse, bamboo and other materials. From the current situation in our country, with the improvement of living standards, the paper consumption increase year by year, paper production is far cannot meet the demand of domestic market. Supply and demand contradiction caused from where?
___________ because of pollution adverse and shut down parts of paper mill, a large number of wheat straw, rice straw into a waste of natural resources. Farmers take incineration field that influence airport, highway traffic safety, seriously polluted the atmosphere, and waste precious renewable resources.
This alkaline paper making is the main pollution cooking black liquor, black liquor treatment domestic approval method is alkali recovery. But this governance method equipment investment is big, the process is long, high energy consumption, operation cost is larger, leaving many paper mills. Biochemical method of black liquor treatment covers an area of large, high investment, the paper mill governance sewage running cost is also high, implement economic burden.
3. Recently, some domestic papermaking enterprises is imported from abroad, a large number of pulp, paper products, and waste paper as raw material of paper making, avoid the sewage disposal problem.
Analysis of China’s paper industry: wood pulp as the main raw material, resource-poor; Relying on imported pulp and paper products, huge financial resources consumption; Development of straw pulp papermaking, black liquor pollution for governance, enterprise unbearable burden on the economy. Stem with a huge amount of resources of straw pulp paper industry a major problem for the survival and development is to take off on the effective and make the enterprise in the economic can accept black liquor pollution control technology. This is a major problem presses for solution of the environmental protection.
China invention patent technology “alkaline pulping, combined organic compound fertilizer is the serious pollution situation in view of the domestic paper industry a high and new technology research and development.
The technology process design can be used for two different types of products:
___________ use paper cooking, shoving pure humic acid organic fertilizer production equipment and process. In cooking pot with potassium hydroxide and catalysts, the various plant straw, stalk, seedling and leaf shattering direct cooking, made of solid and liquid two humic acid organic fertilizer.
2. The potassium hydroxide as pulping papermaking pulping with alkali and add catalyst, process and alkaline basic same, while a process route in the production of pulp black liquor will all into humic acid organic compound fertilizer, black liquor to achieve zero emissions.
This technology is simple, less investment in equipment, no secondary pollution, is not restricted by firm size. Application of this technology in a paper mill in shanxi (30000 tons), industrial gear through trial production, some paper mill in shandong (50000 tons) industrial device trial production, pulp quality, paper has been sold.
Combined humic acid organic fertilizer (liquid) two flower farms in 4 varieties of the Beijing 600 flowers fertilization, in the same period compared with abroad in Israel (4000 yuan/tons of potassium nitrate) and domestic sesame paste residue organic flower fertilizer (price is unknown), through comparing application of almost 5 months, it looks like the flower (miao) until flowering stem, stem, leaf and flower color effect is very obvious, fertilizer is better than that of control group, have gained good reputation enterprise. , watermelon, strawberries and other fruits and vegetable planting field, seedling planting field are demanding order, used to produce green pollution-free organic agricultural products, improve the quality and the selling price.
About humic acid organic fertilizer, it is a new type of organic fertilizer, not in China, foreign also have no, it possesses the advantages of various kinds of organic fertilizer, no smell and no is invalid, for maintenance and improving soil fertility, production green and organic agricultural products, improve the quality of agricultural products, and restore the natural ecology with inorganic fertilizer incomparable role.
This fertilizer is a kind of all water-soluble liquid fertilizer containing humic acid and a large number of organic matter, can cooperate with agricultural sprinkler irrigation, drip irrigation technology, directly to the plant spraying on the leaf and achieve higher fertilizer effect and has a good role in drought resistance, save a lot of water. This material can also be fat and nitrogen, phosphorus, etc in high quality organic compound fertilizer or fertilizer.
Academy of experts think the potassium combined humic acid organic compound fertilizer, its high content of organic matter, rapidly-available potassium and humic acid and a large number of trace elements, is a kind of good quality and high value of agricultural fertilizer, especially suitable for production of green, organic agricultural products. Can be widely used in saline-alkali land management, depleted soil reconstruction, etc. This kind of organic compound fertilizer in vegetables, flowers, planting of Chinese herbal medicine, tea, tobacco and all kinds of nursery foster, fruits and other crops or field crop fertilizer usage, plays an important role to improve product quality, broad market prospects. This technology makes full use of the precious paper and combined humic acid organic compound fertilizer of potassium resources, make the overall balance between supply and demand of potash, and social benefits obvious.

Posted by admin in Environmental protection equipment and tagged with combined humic acid organic fertilizer patent technology, Of potassium

Anthraquinone method fixed bed palladium catalyst system of hydrogen peroxide

Scope of application:
Fertilizer, chlor-alkali chemical industry, petrochemical industry with by-product hydrogen gas
Main contents:
The technology on the carrier of 2 – ethyl anthraquinone, with heavy aromatics such as mixed solvent mixture as working fluid. The working fluid with hydrogen bubbled into the tower of a containing palladium catalytic hydrogenation, hydrogenation, 2 – ethyl anthraquinone hydrogen can be calculated. 2 – ethyl anthraquinone hydrogen oxidation by oxygen in the air is again back to the original 2 – ethyl anthraquinone, at the same time generate hydrogen peroxide. Using hydrogen peroxide in working liquid and water solubility of the different and the working fluid and the density difference of water, extraction with water containing hydrogen peroxide working liquid aqueous solution of hydrogen peroxide. The latter obtained with solvent purification, enrichment, etc., different concentration of hydrogen peroxide products.
Investment and benefit analysis:
Annual output of 10000 tons of 27.5% H2O2, with a total investment of about 30 million yuan; Payback period of 3 years or so. This technology has obvious economic benefits, according to the scale of production, annual after-tax profits of 5 million yuan. Because this technology use in sludge pollution treatment technology, environmental benefit is obvious.
– — – — – — – — – — – the Product Directory

Posted by admin in Environmental protection equipment and tagged with Anthraquinone method fixed bed palladium catalyst system of hydrogen peroxide

Fetor new technology

This technology USES a special high energy high ozone UVc ultraviolet beam, fetor, change the stench gas such as ammonia and trimethylamine, hydrogen sulfide, hydrogen sulfide and methyl mercaptan, sulfur ether, dimethyl disulfide, styrene, carbon disulfide and sulfur H2S, VOC, molecular chain structure of benzene, toluene, xylene, organic or inorganic polymer odorous compounds molecular chain, under high-energy ultraviolet light irradiation, the fracture of the degraded into low molecular compounds, such as CO2, H2O, etc. Using high energy high ozone UVc ultraviolet light decomposition free oxygen, the oxygen molecules in the air that reactive oxygen species, with electron-positron imbalance by free oxygen so need to combine with oxygen, ozone, and thus.
A, efficient except stink: can effectively remove volatile organic compounds (VOC), inorganic matter, main pollutants, such as hydrogen sulfide, ammonia, mercaptan and stench, deodorization efficiency can reach more than 99.9%, deodorization effect considerably more than the 1993 issued odorous pollutants emission standards (GB14551-93).
2, without adding any material, only need to set up the corresponding exhaust pipes and exhaust power, the stench gas purification, deodorization decomposition by this equipment without adding any material to participate in chemical reactions. ,
Three, strong adaptability, can adapt to the high concentration, big volume, different stench gas deodorization purification processing, can work 24 hours per day continuous operation is stable and reliable.
Four, low running cost: this equipment is without any mechanical action, no noise, no need for personnel management and daily maintenance, only need to regularly check, this equipment is low energy consumption, (1000 m3 / h per treatment, only electricity consumes about 0.1 degrees), the equipment is very low wind resistance < 30 pa, can save a lot of wind power energy consumption.
Five, the pretreatment, the stench gas without special pretreatment, such as heating, humidification, equipment working environment temperature in Celsius – 30 o – 95 o.
Equipment cover an area of an area small, light weight, suitable for special conditions, such as narrow compact layout, site equipment covers an area of < 1 square meters.

Posted by admin in Environmental protection equipment and tagged with Fetor new technology

Process analyzer sample processing system technology

Pick to the 21st century cutting-edge technology field of vision to look at process analyzer sample processing system technology, sample processing system technology is process analysis instrument engineering application system (hereinafter referred to as the process analysis system) core and key technology, establish the idea of this technology is of far-reaching significance, the popularization and application of process analysis system, incentive and greatly facilitating role. In this paper, the sample gas handling system of the system, the specific design of sample gas handling system technology, industrial furnaces, chemical process analysis system in the field of engineering application technology. Particularly, affirmed the current r&d sample processing system technology the latest efforts and the latest progress.

Keywords analyzer sample processing system technology process analysis system for the sample parts

1 the status of sample gas handling system in the process of analysis system

Sample processing system if only process gas analysis systems, it is called the sample gas handling system.

Engineering technology in the industry in the process of analysis, sample gas handling system described in this article, the past has been called sampling pretreatment system, the pretreatment system, the gas sample pretreatment system, the sampling and pre-processing units, etc. Due to long with a word “advance”, as if just additional part of the process analyzer, did not receive the attention they deserve.

GB/T 19768-2005 “said analyser sample processing system in the process of” the national standard, actually to standard JB/T 6854-1993: machinery, already cancelled before processing system “forecast”, it is bound to lead; Sample gas handling system and technology concepts and terminology of sample gas handling parts. Unfortunately, for a long time did not get people attention and recognition in the industry.

This article emphatically elaborated the sample gas handling system of technology, has its relative independence, rigor, systemic, control function and software of PLC programmable controller is a proof. Germany H&B company 60 s type dry temperature sampling probe alone there are as many as dozens of sets of sales in the Chinese market, the highest price 1.35 million yuan, is a persuasive proof.

In order to promote the development of process analysis system for engineering application technology, we should have a kind of new technology concept: the process analysis to face many tough complex technical problem, the sample gas handling system is the core and key technology of process analysis system, looking forward to the sample gas handling system from now on to improve and development.

2 process analyzer engineering application technology of sample gas handling system dependent and requirements

2.1 1986 years ago, the domestic various analytical instruments process of advanced analytical instruments are on the market in the form of single machine sales, almost all the German H&B company process analyzer has about two-thirds (including analysis cabin) based on process analysis system on the market, in the form of sample gas handling system at that time there was a “pre” word is not case.

Three technologies such as sic infrared introduction as an opportunity, at the same time from H&B company introduced technology process analysis system, and two training system design and engineering application talent, make the sic inadvertently acted as a pioneer engineering application process analyzer, the role of the design level, application level and the scale of production has a great progress.

2.2 process analyzer the sticking point of engineering application and the best way

Long-term continuous process analyzer, timely detection, strictly necessary for continuous sampling and of sample gas handling technique, require sample gas and transport fast, real sample gas into the analyzer, gas demand reach to standard of quality. Long-term continuous operation process analysis system reliability and security, and easy maintainability, almost no maintenance is fully rely on the pertinence design of sample gas handling system technology.

According to every process analysis system for field application condition and the sampling condition, to adopt specialization, standardization, the specific design of special process analysis system, produced by professional manufacturers with long-term engineering practice experience the process of high quality analysis system, and take the whole process of technical services.

For process gas analysis, is to make the sample gas handling system and decisive technology with different application conditions and the environment conditions match properly, and perfect combination. Process analyzer the absolute dependence of sample gas handling system, making the process analyzer analysis to fill the order form process analysis system is a process engineering technology development, and it’s been in the industry.

This article from the Fabrication Services Suppliers

Posted by admin in Environmental protection equipment and tagged with Process analyzer sample processing system technology