CN212231089U - Real standard platform surge suppression circuit of car - Google Patents

Abstract

The utility model discloses a real standard platform surge suppression circuit of car, including the opto-coupler, shunt, the relay of establishing ties between drive power supply and load, the output of shunt is connected with the collecting electrode of opto-coupler, and the projecting pole of opto-coupler is connected with a switch end of relay, and the voltage detection end of shunt controls the opto-coupler to turn off and switch on through operational amplifier; the output end of the shunt is connected with one end of a second resistor and the collector of the triode, the other end of the second resistor is connected with one end of a capacitor and the base of the triode, the other end of the capacitor is connected with the ground, and the emitter of the triode is connected with the emitter of the optocoupler through a third resistor. When the current of the current divider is too large, the optocoupler is switched off to enable the triode to be switched on, in the time period, the second resistor charges the capacitor, the driving power supply provides current for the load through the third resistor and the triode, the third resistor shares partial voltage, the load current is reduced, and the voltage at the two ends of the capacitor is increased to be enough to switch off the triode.

Description

Real standard platform surge suppression circuit of car

Technical Field

The utility model relates to a teaching aid, in particular to real standard platform surge suppression circuit of car.

Background

The existing teaching demonstration box for automobile training generally concentrates all basic elements of automobile load in the same box body, and supplies power after a battery system or an alternating current power supply is converted into direct current. Surge is instantaneous over-current occurring in a circuit, and is transient current and voltage fluctuation which rises quickly and then falls slowly. The damage of surge voltage to the circuit is mainly caused by that the generated overvoltage exceeds the rated voltage of an electrical element, so that the electrical element is damaged, a PN junction is broken down, a control circuit fails to control, a circuit short circuit is seriously caused to cause fire, and in addition, different switching loads can be frequently switched for a long time during teaching, so that the condition of overlarge current often appears in the loads. If the condition of overlarge current is not processed in time, the load is often damaged, and the teaching work is influenced. The surge voltage in the circuit is usually suppressed by adopting a transient voltage suppression diode (TVS tube) for voltage limitation, but the TVS tube is easy to be broken down to cause short circuit when the surge is overlarge, and the consequence is more serious.

Disclosure of Invention

The utility model provides a real standard platform surge suppression circuit of car can restrain too high voltage in certain length and act on the load. Specifically, the method comprises the following steps: an automobile practical training platform surge suppression circuit comprises an operational amplifier, an optical coupler U1, a shunt FL, a first resistor R1, a variable resistor Rw, a triode Q1, a second resistor R2, a third resistor R3 and a capacitor C, wherein the input end of the shunt FL is connected with the positive electrode of a driving power supply, the output end of the shunt FL is connected with the collector electrode of the optical coupler U1, the emitter electrode of the optical coupler U1 is connected with a switching end of a relay K, the voltage detection end of the shunt FL is connected with the inverting input end of the operational amplifier, the output end of the operational amplifier is connected with the positive electrode of the optical coupler U1, the negative electrode of the optical coupler U1 is connected with the ground, the non-inverting input end of the operational amplifier is respectively connected with one end of the first resistor R23 and one end of the variable resistor Rw, the other end of the variable resistor Rw is connected with the ground, and the other end of the first resistor R1; the output end of the current divider FL is connected with one end of a second resistor R2 and the collector of a triode Q1, the other end of the second resistor R2 is connected with one end of a capacitor C and the base of the triode Q1, the other end of the capacitor C is connected with the ground, and the emitter of the triode Q1 is connected with the emitter of an optocoupler U1 through a third resistor R3.

Further, the transistor Q1 is an NPN transistor.

The beneficial effects of the utility model are that, utilize shunt FL when the electric current is too big, in time cut off drive power supply and relay K's lug connection, make triode Q1 switch on, until the voltage at electric capacity C both ends risees to the time of being enough to turn off triode Q1, in this time quantum, second resistance R2 charges for electric capacity C, drive power supply provides the electric current for the load through third resistance R3 and triode Q1, third resistance R3 has shared partial pressure, make load current reduce. When the current passing through the current divider FL is reduced after surge elimination, the optocoupler U1 is conducted, the third resistor R3 and the triode Q1 are short-circuited, and the driving power supply provides current for the load through the current divider FL and the optocoupler U1. If the charging end voltage of the capacitor C is still higher, the third resistor R3 and the optocoupler U1 are both turned off.

Drawings

The invention is described in further detail below with reference to the accompanying drawings and preferred embodiments:

fig. 1 is a circuit diagram of a preferred embodiment of the surge suppression circuit of the present invention.

Detailed Description

Referring to fig. 1, an automobile practical training platform surge suppression circuit includes an operational amplifier UA, an optical coupler U1, a shunt FL, a first resistor R1, a variable resistor Rw, a triode Q1, a second resistor R2, a third resistor R3, and a capacitor C, an input end of the shunt FL is connected to an anode of a driving power supply, an output end of the shunt FL is connected to a collector of the optical coupler U1, an emitter of the optical coupler U1 is connected to a switching end of the relay K, a voltage detection end of the shunt FL is connected to an inverting input end of the operational amplifier UA, an output end of the operational amplifier UA is connected to an anode of the optical coupler U1, a cathode of the optical coupler U1 is connected to ground, a non-inverting input end of the operational amplifier UA is connected to one end of the first resistor R1, one end of the variable resistor Rw is connected, the other end of the variable resistor Rw is connected to ground, and the other end of the first resistor R1 is connected; the output end of the current divider FL is connected with one end of a second resistor R2 and the collector of a triode Q1, the other end of the second resistor R2 is connected with one end of a capacitor C and the base of the triode Q1, the other end of the capacitor C is connected with the ground, and the emitter of the triode Q1 is connected with the emitter of an optocoupler U1 through a third resistor R3.

When the current I is normal, the reference voltage is larger than the voltage output by the voltage detection end, the operational amplifier UA outputs high level, the collector and the emitter of the optical coupler U1 are conducted, the current I normally flows into a load, when the current I is overlarge, the voltage output by the voltage detection end is larger than the reference voltage, the operational amplifier UA outputs low level, the collector and the emitter of the optical coupler U1 are cut off, the current I is cut off, and a voltage difference is generated between the collector and the emitter of the triode Q1, the shunt FL charges the capacitor C through the second resistor R2, when the base voltage of the triode Q1 is larger than the emitter and smaller than the collector, the triode Q1 is conducted, the driving power supply provides current for the load through the third resistor R3 and the triode Q1, and the third resistor R3 shares partial voltage, so that the load current is reduced. Until the voltage at the two ends of the capacitor C rises to be enough to turn off the triode Q1, if surge is eliminated at the time, the optocoupler U1 is switched on to enable the triode Q1 to be short-circuited, the driving power supply resumes to supply power to the load through the optocoupler U1, and if the charging end voltage of the capacitor C is still high, the third resistor R3 and the optocoupler U1 are both switched off.

While the preferred embodiments of the present invention have been described in detail, it will be understood by those skilled in the art that the invention is not limited to the details of the embodiments shown, but is capable of various modifications and changes without departing from the spirit of the invention.

Claims (2)

1. A surge suppression circuit of an automobile practical training platform comprises an operational amplifier, an optocoupler U1, a shunt FL, a first resistor R1, a variable resistor Rw, a triode Q1, a second resistor R2, a third resistor R3 and a capacitor C, the input end of the shunt FL is connected with the positive electrode of a driving power supply, the output end of the shunt FL is connected with the collector electrode of the optocoupler U1, the emitting electrode of the optical coupler U1 is connected with a switch end of the relay K, the voltage detection end of the current divider FL is connected with the inverting input end of the operational amplifier, the output end of the operational amplifier is connected with the anode of an optical coupler U1, the cathode of the optical coupler U1 is connected with the ground, the non-inverting input ends of the operational amplifier are respectively connected with one end of a first resistor R1, one end of the variable resistor Rw is connected, the other end of the variable resistor Rw is connected to the ground, and the other end of the first resistor R1 is connected with a working power supply; the output end of the current divider FL is connected with one end of a second resistor R2 and the collector of a triode Q1, the other end of the second resistor R2 is connected with one end of a capacitor C and the base of the triode Q1, the other end of the capacitor C is connected with the ground, and the emitter of the triode Q1 is connected with the emitter of an optocoupler U1 through a third resistor R3.

2. The surge suppression circuit according to claim 1, wherein said transistor Q1 is an NPN transistor.

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