CN107634743A - Overcurrent protection drive circuit and power windows electric machine controller - Google Patents

Abstract

A kind of overcurrent protection drive circuit, it is characterised in that including time base circuit IC1, timing capacitor C1, first resistor R1, the first diode D1, the first voltage-stabiliser tube D2,3rd resistor R3, power tube Q1；The negative pole ground connection of time base circuit, positive pole and clearing termination positive source, output end connects power tube input, one end of low triggering end and timing capacitor, one end of first resistor, the negative pole of first diode connects simultaneously, the other end ground connection of timing capacitor, the other end of first resistor, the positive pole of first diode is connected with the discharge end of time base circuit simultaneously, the positive pole of first voltage-stabiliser tube or the connection of the high-triggering end of one end of second resistance and time base circuit, the negative pole of first voltage-stabiliser tube or the connection of the discharge end of the other end of second resistance and time base circuit, the negative pole ground connection of power tube, power tube output end is connected by 3rd resistor with discharge end；Circuit structure is simple, overcurrent protection is sensitive, small volume, cost are low, it is easy to spread, be widely used.

Description

Overcurrent protection drive circuit and power windows electric machine controller

Technical field

The invention belongs to technical field of electronic control, and in particular to overcurrent protection drive circuit and power windows motor control Device.

Background technology

Various direct current supplys load is required for being controlled its operating current by control device, including DC control and Pulse current controls, such as control of power windows motor, and this technology that anti-overcurrent etc. is just proposed to power tube will Ask.

But the control circuit of prior art has following technical problem：

1st, much do not possess power tube overcurrent protection function, once overcurrent overheat, power tube easily damages.

2nd, partly there is the circuit of overcurrent protection function, usually series connection high current resistance is carried out on the main line of power device Current sample, when electric current is exceeded, rupturing duty pipe input control signal again is judged by comparison circuit, between this method belongs to Stream sampling is taken over, its sampled signal comparison power tube excessively stream generation moment has lagged, and often serious excessively stream just starts Protection act, result are to damage caused by power tube excessively stream still more, reduce the reliability of circuit.

3rd, circuit structure described in above-mentioned 2 is also complex, cost is high and performance is undesirable.

Or the shortcomings that the 4th, partly possessing the special integrated chip of overcurrent protection function and being lagged with above-mentioned protection, want Its cost is higher.

5th, partly possessing the drive circuit of overcurrent protection function does not have the auto-reset function after overcurrent protection, and this needs electricity Reset is restarted on road or matching oscillating circuit produces reset pulse progress separate excitation reset in addition on circuit, and this makes circuit more tired It is trivial.

6th, the drive circuit volume for partly possessing overcurrent protection function is larger.

Because power driving circuit purposes is extremely extensive, so needing R ＆ D design to go out, circuit is relatively simple, cost is relatively low, body Product is small, " the overcurrent protection drive circuit " of detection excessively stream and protection act timely high reliability.

The content of the invention

It is an object of the present invention to design a kind of " overcurrent protection drive circuit ", it can reduce or overcome above-mentioned drawback, carry The reliability of high drive circuit, especially in power windows electric machine controller.

To achieve the above object, according to the first aspect of the present invention, there is provided a kind of overcurrent protection drive circuit, its is special Part is, including

Time base circuit IC1, timing capacitor C1, first resistor R1, the first diode D1, the first voltage-stabiliser tube D2 or second resistance R2,3rd resistor R3, power tube Q1, the power cathode ground connection of the time base circuit, the positive pole and clear terminal of the time base circuit Positive source is connected, the output end of the time base circuit connects the power tube input, the low triggering end of the time base circuit One end of one end, the first resistor with the timing capacitor, the negative pole of first diode connect simultaneously, the timing Electric capacity the other end ground connection, the other end of the first resistor, first diode positive pole simultaneously with the time base circuit Discharge end connection, the positive pole of first voltage-stabiliser tube or one end of second resistance and the high-triggering end of the time base circuit connect Connect, the negative pole of first voltage-stabiliser tube or the other end of second resistance are connected with the discharge end of the time base circuit, the power The negative pole ground connection of pipe, the power tube output end are connected by 3rd resistor with the discharge end of the time base circuit.

Further, present invention also offers a kind of overcurrent protection drive circuit, it is characterized in that, base electricity when described Road is 555 integrated chips.

Further, present invention also offers a kind of overcurrent protection drive circuit, it is characterized in that, base electricity when described The threshold value end on road is connected to voltage-regulator diode over the ground.

According to the second aspect of the present invention, there is provided a kind of power windows electric machine controller, it is characterized in that, described Overcurrent protection drive circuit any one of power windows electric machine controller aforementioned first aspect.

The invention has the advantages that overcurrent protection is sensitive, safe and reliable, circuit is relatively simple, cost is relatively low, volume It is small.

Brief description of the drawings

Fig. 1 is the overcurrent protection driving circuit structure schematic diagram that first aspect present invention embodiment provides；

Fig. 2 is another overcurrent protection driving circuit structure schematic diagram that first aspect present invention embodiment provides；

Fig. 3 is another overcurrent protection driving circuit structure schematic diagram that first aspect present invention embodiment provides；

Fig. 4 is that a little adjustable overcurrent protection driving circuit structure that starts to control that first aspect present invention embodiment provides shows It is intended to；

Fig. 5 is the power windows motor control including overcurrent protection drive circuit that first aspect present invention embodiment provides Device structural representation processed.

Embodiment

With reference to the accompanying drawings and examples, the embodiment of the present invention is done to be described in further detail, embodiment The present invention is merely to illustrate, is not intended to limit the present invention, interest field of the invention is defined by the claims.

In a first aspect, embodiment of the present invention provides a kind of overcurrent protection drive circuit.

Embodiment 1

As shown in figure 1, the architectural feature of the circuit is, including time base circuit IC1, timing capacitor C1, first resistor R1, One diode D1, the first voltage-stabiliser tube D2 or second resistance R2,3rd resistor R3, power tube Q1, the power cathode (1) of time base circuit Ground connection, positive pole (8) the connection positive source Vc of time base circuit, clear terminal (4) the connection external control signal of time base circuit or company Meet positive source Vc, output end (3) the connection power tube Q1 inputs of time base circuit, the low triggering end (2) of time base circuit and calmly When electric capacity C1 one end, first resistor R1 one end, the first diode D1 negative pole connect simultaneously, the timing capacitor C1 other end E is grounded, the first resistor R1 other end, the first diode D1 positive pole are connected with the discharge end (7) of time base circuit simultaneously, and first The high-triggering end (6) of voltage-stabiliser tube D2 positive pole or second resistance R2 one end and time base circuit connects, and the first voltage-stabiliser tube D2's is negative Discharge end (7) connection of pole or second resistance the R2 other end and time base circuit, power tube use FET, its source electrode conduct Negative pole is grounded E, and power tube output end OUT is connected by the discharge end of 3rd resistor R3 and time base circuit (7).

Its course of work is described below：(in figure by taking clear terminal (4) the connection connection positive source Vc of time base circuit as an example)

(1) when electric on, because electric capacity C1 both end voltages can not be mutated, therefore time base circuit integrated chip IC1 is (with NE555 Exemplified by) 2 pin be low level, it is also low level that 6 pin are clamped down on by voltage-stabiliser tube D2, therefore its pin of output end 3 is high level output, together When the pin of discharge end 7 end over the ground, 3 pin output high level make power tube Q1 (in figure by taking FET as an example, according to practical application Need be IGBT or Darlington etc.) conducting, power tube Q1 drain electrode output low levels, make time base circuit by resistance R3 2 pin are that low level, 6 pin are also clamped, therefore IC1 3 pin still export that high level, 7 pin are still off over the ground, and this state is steady State.

(2) when excessively stream occurs for power tube Q1, the pressure drop in its internal resistance is that drain voltage (VD) will raise, and the voltage leads to Cross resistance R3, diode D1 faster charges to electric capacity C1, when voltage be flushed to rapidly higher than when the high activation threshold value of base chip internal During voltage (being generally set 2/3Vc), IC1 is overturn, 3 pin output low level, power tube Q1 cut-offs, its drain voltage VD (that is, power tube saturation voltage drop) is connect load and drawn high to power supply voltage, while IC1 7 pin internal discharge tubes are led over the ground Logical, electric capacity C1 is slowly discharged (now D1 ends) by resistance R1 and 7 pin internal discharge tubes, until electric capacity C1 tension discharges are to low When internal low activation threshold value voltage (being generally set 2/3Vc), it is high level output that chip overturns as 3 pin again, simultaneously The pin of discharge end 7 ends over the ground, and such power tube Q1 recovers conducting, power tube Q1 drain electrode output low levels, and C1 continues electric discharge but right State is without influence.

(3) it can add and receive external control signal, so that the circuit turns into the controlled drive with overcurrent protection function Dynamic circuit, common method can have reception high level signal or the pin of clear terminal 4 on the pin of high-triggering end 6 to be changed to receive control Signal or resistance is sealed between the pin of output end 3 and power tube gate input, then additional control power tube input Method, can receive level controling signal or pulse control signal, and can also according to the control pulse frequency received, R1, C1, R3 parameter are rationally designed, adjusts overcurrent protection off-period, to adapt to physical circuit for cut-out reset and excessively stream Protection resets two aspects and takes into account needs.

This drive circuit with overcurrent protection function of the present invention, makes direct sampled power pipe saturation voltage drop, compares For other sampling main line current samples, the method for main line current sample is often that the curent change of sample resistance lags behind power Pipe saturation voltage drop overflows, and some are that the pressure drop ability protection circuit that experienced after some control pulse periods on sample resistance is just dynamic Make, actual power pipe excessively stream several cycles already, so such protection circuit is not only complicated, volume is big, generate heat more, Er Qiebao Protective function is unreliable, but such circuit application is still relatively broad so far.

And the protection circuit of technical solution of the present invention, in time under Pulse Width Control, when excessively stream once occurs for power tube, drain electrode Saturation voltage drop rapidly overturns IC1 to be controlled in time, and practical application shows, circuit reliability is high.And circuit structure is very Simply, do not have high current sample resistance, small volume, heating less, cost it is low, for DC level control circuit and pulse duty factor Control is all equally applicable, and application prospect is extensive.

Embodiment 2

As shown in Fig. 2 time base circuit is 555 integrated chips.The circuit instead of surely compared with earlier figures 2 with resistance R2 Pressure pipe D2, the drain voltage during power tube overvoltage transmitted through R3 is may also function as,

Embodiment 3

As shown in figure 3, the architectural feature of the circuit is, the pin of threshold value end 5 of time base circuit is connected to voltage-regulator diode D5 over the ground, Due to adjusting electric capacity C1 charging upper limits, when D5 voltage stabilizing value is less than the high activation threshold value voltage of chip internal, overcurrent protection is moved Make sensitivity raising, and D5 voltage stabilizing value reduction overcurrent protection is started to control current value and can reduced, and overcurrent protection is more sensitive.May be used also To adjust excessively stream default time, when continuous excessively stream, power tube drains and will occurred by certain frequency of oscillation of C1 charge and discharge electric forming Pulse, wherein C1 charging interval is excessively stream default time, and its dutycycle is typically designed relatively low, can be less than 1%, this It can be determined according to calculating and combining the test of actual circuit component test.Practice have shown that continuous overcurrent protection when dutycycle is excessive In the case of power tube heating it is excessive, be easily damaged.

Embodiment 4

As shown in figure 4, the architectural feature of the circuit is, the pin of threshold value end 5 of time base circuit is connected to adjustable resistance R4 over the ground, together Sample also functions to adjustment overcurrent protection and starts to control effect a little, the reduction of R4 resistances, and morning is started to control in overcurrent protection, can be according to the normal work of circuit The size of current of work, power tube turn on the parameter binding tests such as internal resistance and rationally set R4 resistances, so that the sensitive safety of overcurrent protection Be not in because the factors such as power tube temperature rise internal drag curve cause over-current protection malfunction to be made again, it is of course possible to add temperature on R3 again Drift amendment resistance is changed with power tube internal resistance caused by offsetting temperature rise, for some circuits, can also be set exclusively with temperature rise Protection point is put, this needs needs to select the temperature coefficient of suitable correction of temperature drift resistance according to function.

Second aspect, embodiment of the present invention provide a kind of power windows electric machine controller, and its architectural feature is, electricity The overcurrent protection drive circuit of any one of motor-car window electric machine controller aforementioned first aspect.

Embodiment 5

As shown in figure 5, the architectural feature of the circuit is, power windows circuit for controlling motor includes direct current generator M, rotating Relay L1 and L2, motor elevating control chip 200, wherein motor elevating control chip 200 also have other pins to connect respectively Control button, vehicle-mounted car body control module, communication terminal etc., it is not shown in these conventional line figures.There is motor to supply in addition Electrical relay L3.

In figure, IGN is that to control power supply, B+ be the direct-connected power supply of battery to ignition switch, E is ground connection.

It will be that over-current protecting unit 100 is cancelled in figure that traditional connection, which is, the relay for the motor M being connected with OUT terminal Control line is directly grounded, thus without overcurrent protection function.

Fig. 5 over-current protecting unit 100 adds current-limiting resistance R4 and voltage-stabiliser tube D3 compared with Fig. 4, and this is to protect IC1, prevent the various throw load overvoltages in vehicle supply line from being damaged to IC1.

The power windows control circuit of connection as illustrated, when over current of motor occurs, the triggering of power tube Q1 drain potentials The pin of IC1 chips 2, overturns IC1, and power tube cut-off, electric motor loop is cut off, and motor stalling, motor is protected, power tube Q1 It is also protected with.If sequential short circuit or continuous excessively stream, by the pulse of certain frequency of oscillation of C1 charge and discharge electric forming, due to its work( Rate pipe conducting dutycycle is extremely low, and power tube will not largely generate heat, and short circuit or excessively stream will not also damage motor or power tube for a long time, Relay, insurance, circuit, battery are protected from simultaneously, are also avoided because Car window electric machine short circuit causes vehicle incidents of spontaneous combustion Occur.When excessively stream or short circuit release, circuit recovers normal automatically.

Claims (4)

1. A kind of 1. overcurrent protection drive circuit, it is characterised in that including

   Time base circuit IC1, timing capacitor C1, first resistor R1, the first diode D1, the first voltage-stabiliser tube D2 or second resistance R2, 3rd resistor R3, power tube Q1, the power cathode ground connection of the time base circuit, the positive pole of the time base circuit connect with clear terminal Positive source, the output end of the time base circuit connect the power tube input, the low triggering end of the time base circuit and institute State one end of timing capacitor, one end of the first resistor, first diode negative pole and meanwhile connect, the timing capacitor Other end ground connection, the other end of the first resistor, the positive pole of first diode are put with the time base circuit simultaneously Electric end connection, the positive pole of first voltage-stabiliser tube or one end of second resistance are connected with the high-triggering end of the time base circuit, institute State the negative pole of the first voltage-stabiliser tube or the other end of second resistance is connected with the discharge end of the time base circuit, the power tube is born Pole is grounded, and the power tube output end is connected by 3rd resistor with the discharge end of the time base circuit.
2. 2. overcurrent protection drive circuit according to claim 1, it is characterised in that the time base circuit is 555 integrated cores Piece.
3. 3. overcurrent protection drive circuit according to claim 2, it is characterised in that the threshold value end of the time base circuit is over the ground It is connected to voltage-regulator diode.
4. 4. a kind of power windows electric machine controller, it is characterised in that driven including the overcurrent protection described in any one of claims 1 to 3 Dynamic circuit.