CN201656773U

CN201656773U - High-voltage frequency converter drive circuit

Info

Publication number: CN201656773U
Application number: CN2010201216867U
Authority: CN
Inventors: 石泉
Original assignee: Yapai Science and Technology Industry Co Ltd Nanjing
Current assignee: Yapai Science and Technology Industry Co Ltd Nanjing
Priority date: 2010-03-02
Filing date: 2010-03-02
Publication date: 2010-11-24
Anticipated expiration: 2020-03-02

Abstract

The utility model discloses a high-voltage frequency converter drive circuit which has the advantages of simple and convenient circuit, low cost and greatly reduced energy loss. The high-voltage frequency converter drive circuit comprises a PWM (pulse-width modulation) signal access end, a triode T1, a base resistor R1 of the triode T1, a connector resistor R2 of the triode T1, a driving chip, a series resistor R3 on the output side and a drive end optical fiber head HFBR-1521, and is characterized in that the driving chip adopts a push-pull circuit consisting of an NPN transistor and a PNP transistor which are in series connection, base electrodes of the NPN transistor and the PNP transistor are connected to the end of the resistor R2 together, which is connected with the collector electrode of the triode T1, the collector electrode of the NPN transistor is connected to the other end of the resistor R2 and a power source VCC, and the collector electrode of the PNP transistor is connected to the emitting electrode of the triode T1 and is grounded.

Description

A kind of driving circuit of high-voltage frequency converter

Technical field

The utility model relates to a kind of circuit, more specifically to a kind of driving circuit of high-voltage frequency converter, belongs to field of power electronics.

Background technology

Development along with power electronic technology, the power of IGBT module is increasing, dc voltage is more and more higher, operating frequency is also more and more higher, the problem of thereupon bringing is interfering with each other between the drive signal, when long distance drives transmission, high-frequency current is to the interference signal of drive signal in the frequency converter, cause distortion, problems such as time-delay are in order to avoid these problems, engineers has adopted a lot of methods all not obtain very good effect, be referred to the driving field up to optical fiber technology, interference problem has just obtained basic solution, and has obtained extensive use very soon.And the optical fiber driving needs the special driving chip, this chip somewhat expensive (general about 10 yuan), and with when the optical fiber emitting head is connected work, failure rate is very high, simultaneously because chip for driving and optical fiber head alternation, makes the power supply continuous firing, for pwm signal, wasted one times power supply energy, the volume of power supply increases and is twice, for requiring today the more and more littler trend of machine to run in the opposite direction.

As shown in Figure 1, what existing driving circuit of high-voltage frequency converter generally adopted is the DS75741 chip for driving, this chip internal can equivalence be the structure that a not gate drives a triode job, it is a kind of chip for driving commonly used, a series of problems of its existence have been found through a large amount of application in early stage, say that as top institute because long-term high-frequency current, the failure of chip rate is very high; Adopt this working method simultaneously, optical fiber head and chip for driving DS75741 alternation, high or low no matter pwm signal is in, inculcating electric current is continuous firing 60mA, will be a no small waste for energy consumption.As Fig. 1, during work, it is the pwm signal of 5V that signal end inserts amplitude, and when PWM was high level, the triode base was penetrated pressure drop and is about 0.7V, base current is about (5-0.7)/2K=2.15mA, because the HFE of triode is 100, resistance R 2 is 10K, so triode is in saturation condition, be output as low level, according to the logic of DS75741, the conducting of chip internal triode is in saturation condition, output voltage is the about 0.3V of triode saturation voltage drop, so pressure drop is about 4.7V above the pull-up resistor R3, this moment, optical fiber head was not worked, and the electric current on the pull-up resistor R3 is 4.7/51=92mA, power consumption mainly on R3, is approximately 0.5W.

When PWM is low level, triode is in cut-off state, so collector electrode is output as high level 5V, logic level according to chip for driving, inner triode ends, be equivalent to open circuit, so this time, electric current all flows to the light-emitting diode of optical fiber head HFBR-1521 inside by R3, because the about 1.6V of interior light emitting diodes pressure drop, non-essential resistance R3 go up resistance and be about 3.4V, the HFBR-1521 operating current is about 3.4/5.1=67mA, power consumption is about 0.33W, and the relative PWM of power consumption descends when being high level to some extent.But generally speaking, no matter optical fiber head work with do not work, circuit all dissipation of energy can occur, and is very unreasonable.And the power consumption of optical fiber head when not working is bigger, from this aspect, extremely waste energy, the requirement to power supply simultaneously also increases, highly energy-consuming also can influence to some extent to the life-span of device in addition, therefore the driving circuit of high-voltage frequency converter that needs a kind of more simple cheap of exploitation and do not waste energy.

Summary of the invention

The utility model has well solved above-mentioned the deficiencies in the prior art and problem, and a kind of driving circuit of high-voltage frequency converter is provided, and the simple and convenient cost of this circuit is low, conserve energy loss greatly simultaneously.

The technical solution of the utility model is as follows:

Driving circuit of high-voltage frequency converter of the present utility model, include the pwm signal incoming end, triode T1, the base resistance R1 of triode T1, the collector resistance R2 of triode T1, chip for driving, the series resistor R3 of outlet side and drive end optical fiber head HFBR-1521, it is characterized in that described chip for driving is a NPN pipe and the push-pull circuit that the PNP pipe is composed in series, the NPN pipe is connected to the end that resistance R 2 is connected with the collector electrode of triode T1 jointly with the base stage of PNP pipe, the NPN pipe collector is connected to resistance R 2 other ends, and be connected on the power supply VCC, the collector electrode of PNP pipe is connected to the emitter of triode T1, and is connected to ground.

Driving circuit of high-voltage frequency converter of the present utility model, its further technical scheme is that described pwm signal access amplitude is 5V, the pwm signal incoming end is connected with the base resistance R1 of triode T1, the size of resistance R 1 is 51K, the size of the collector resistance R2 of triode T1 is 2K, and resistance R 3 sizes that are connected in series with the emitter of NPN pipe and PNP pipe are 30 Europe, and resistance R 3 is received 1 pin of optical fiber head HFBR-1521, and keep the parallel resistance R4 between 1 pin and 2 pin, the size of R4 is 2K.When optical fiber is length about 2 meters, R3 can select 60 ohm resistance for use, and this moment, drive current was 35mA more, and driving force can reach requirement.

Driving circuit of high-voltage frequency converter of the present utility model, its further technical scheme can also be that the pwm signal incoming end at this driving circuit of high-voltage frequency converter is parallel with a filter capacitor and comes the filtering peak voltage; Further technical scheme is that the size of filter capacitor is 10PF when pwm signal access amplitude is 5V again.

Driving circuit of high-voltage frequency converter of the present utility model, the big I of the series resistor R3 that its further technical scheme can also be described chip for driving outlet side is adjusted to satisfy the desired drive current of driving force according to the length of fibre circuit.

The utlity model has following beneficial effect:

When driving circuit of high-voltage frequency converter of the present utility model is high level when pwm signal, the push-pull circuit optical fiber head is not all worked, so there is not energy loss, when pwm signal when being low level, optical fiber head energy operate as normal, and voltage has been divided into basic three average parts, a part is on the light-emitting diode of optical fiber head inside, another part is on R3, some is on the NPN triode, so more disperse than original two parts heat,, so just increased the working life of device so that temperature rise also can further reduce.Because energy consumption has reduced not enough original half, so that power supply also can be done is littler, can be controlled better on the cost, can save cost greatly.Simultaneously because the dispersion of energy loss makes the life-span of device to improve greatly.On general knowledge, also know in addition, simple combination of devices, its performance is stable more, and the out of order probability of Fu Za combination is big more, so the reliability of this circuit also can further improve.Owing to be to adopt simple individual devices combination,, can be more widely used so the response time also can further improve.

Description of drawings

Fig. 1 is existing driving circuit of high-voltage frequency converter structural representation

Fig. 2 is a driving circuit of high-voltage frequency converter electrical block diagram of the present utility model

Embodiment

Below in conjunction with accompanying drawing the utility model technology contents is explained:

As shown in Figure 2, driving circuit of high-voltage frequency converter of the present utility model, include the pwm signal incoming end, triode T1, the base resistance R1 of triode T1, the collector resistance R2 of triode T1, chip for driving, the series resistor R3 of outlet side and drive end optical fiber head HFBR-1521, it is characterized in that described chip for driving is a NPN pipe and the push-pull circuit that the PNP pipe is composed in series, the NPN pipe is connected to the end that resistance R 2 is connected with the collector electrode of triode T1 jointly with the base stage of PNP pipe, the NPN pipe collector is connected to resistance R 2 other ends, and be connected on the power supply VCC, the collector electrode of PNP pipe is connected to the emitter of triode T1, and is connected to ground.It is 5V that described pwm signal inserts amplitude, the pwm signal incoming end is connected with the base resistance R1 of triode T1, the size of resistance R 1 is 51K, the size of the collector resistance R2 of triode T1 is 2K, resistance R 3 sizes that are connected in series with the emitter of NPN pipe and PNP pipe are 30 Europe, resistance R 3 is received 1 pin of optical fiber head HFBR-1521, and keeps the parallel resistance R4 between 1 pin and 2 pin, and the size of R4 is 2K.

The present embodiment signal end inserts the pwm signal that amplitude is 5V equally, and when PWM was high level 5V, the triode base was penetrated pressure drop and is about 0.7V, and base current is about (5-0.7)/51K=0.084mA.Because the HFE of triode is 100, resistance R 2 is 2K, according to the current amplification factor of triode, be easy to obtain triode and be in saturation condition, be output as low level, be about 0.3V, in push-pull circuit, the NPN triode is in cut-off state, so push-pull circuit output is equivalent to off state, the input side of DS75741 is a low level, and DS75741 is in off position, because no current flows through push-pull circuit and optical fiber head, so basic noenergy loss.

When PWM was low level, the base stage no current flow through, so triode T1 is in cut-off state, collector electrode is output as high level 5V, and the NPN plumber of push-pull circuit does, and the PNP pipe ends.Show according to experimental data, the last voltage of R2 is 0.8V, the base stage of the NPN pipe of push-pull circuit. press to be 0.7V, the last voltage of R3 is 1.9V, the light-emitting diode of optical fiber head inside is 1.6V, and the Vce of NPN pipe is 1.5V, and the operating current that can calculate optical fiber head according to the voltage on the R3 is 1.9V/30 Europe=63mA, running parameter by HFBR-1521 learns that this electric current can satisfy the operate as normal of optical fiber head.

Claims

1. driving circuit of high-voltage frequency converter, include the pwm signal incoming end, triode T1, the base resistance R1 of triode T1, the collector resistance R2 of triode T1, chip for driving, the series resistor R3 of outlet side and drive end optical fiber head HFBR-1521, it is characterized in that described chip for driving is a NPN pipe and the push-pull circuit that the PNP pipe is composed in series, the NPN pipe is connected to the end that resistance R 2 is connected with the collector electrode of triode T1 jointly with the base stage of PNP pipe, the NPN pipe collector is connected to resistance R 2 other ends, and be connected on the power supply VCC, the collector electrode of PNP pipe is connected to the emitter of triode T1, and is connected to ground.

2. driving circuit of high-voltage frequency converter according to claim 1, it is characterized in that it is 5V that described pwm signal inserts amplitude, the pwm signal incoming end is connected with the base resistance R1 of triode T1, the size of resistance R 1 is 51K, the size of the collector resistance R2 of triode T1 is 2K, and resistance R 3 sizes that are connected in series with the emitter of NPN pipe and PNP pipe are 30 Europe, and resistance R 3 is received 1 pin of optical fiber head HFBR-1521, and keep the parallel resistance R4 between 1 pin and 2 pin, the size of R4 is 2K.

3. driving circuit of high-voltage frequency converter according to claim 1 is characterized in that pwm signal incoming end at this driving circuit of high-voltage frequency converter is parallel with a filter capacitor and comes the filtering peak voltage.

4. driving circuit of high-voltage frequency converter according to claim 3 is characterized in that the size of filter capacitor is 10PF when pwm signal access amplitude is 5V.

5. driving circuit of high-voltage frequency converter according to claim 1 is characterized in that the big I of the series resistor R3 of described chip for driving outlet side is adjusted to satisfy the desired drive current of driving force according to the length of fibre circuit.