CN103647443A - SCR efficient control circuit - Google Patents

Abstract

Provided is a SCR efficient control circuit. Resistors R1 and R2 are connected with a Fire A and a Fire B through optocouplers U1 and U2; a capacitor C3 and a resistor R3 are connected between a connecting point K4 and the optocoupler U1; a resistor R6 is connected to a voltage-stabilizing tube D3, the resistor R2 and a switch tube Q2; a diode D1 is connected to the switch tube Q2; the switch tube Q2 is connected with the voltage-stabilizing tube D3 and a switch tube Q1; resistors R7 and R8 are connected with a diode D4 after being in series connection with each other, and the diode D4 is connected with a resistor R5 through a diode D5; resistors R9 and R10 are connected with a diode D7 after being in series connection with each other, the diode D7 is connected with a resistor R13 through a diode D8, and the resistor R13 is connected with an optocouplers U5; a voltage-stabilizing tube D9 is connected with the optocouplers U5; a resistor R14 is connected between a connecting point K1 and the optocouplers U5; a resistor R16 is connected with a voltage-stabilizing tube D10, a resistor R11 and a switch tube Q4; the switch tube Q4 is connected with the optocouplers U5 and a resistor R12 through a switch tube Q3, and the resistor R12 is connected with a connecting point G1 and a capacitor C14. When an SCR is not connected, two ends of the connecting points K1 and K4 have voltage and directly act on control electrodes of the switch tubes by resistance voltage division, and the connection conditions are met. The SCR efficient control circuit has the advantages of being efficient and reliable and automatically taking power.

Description

The efficient control circuit of a kind of SCR

Technical field

The invention belongs to the control technology field of power electronics semiconductor device SCR, particularly the efficient control circuit of a kind of SCR, is applicable to power controller, AC power and In Asynchronous Motor Soft Starter.

Background technology

Progress along with power electronic technology, the increase day by day of motor soft starter, AC power application quantity, traditional pulse transformer control circuit is longer its current rise time, easily produce electromagnetic interference, historical facts or anecdotes border poor effect, and independent power supply need be provided, and power consumption, volume, weight are larger, and it is not too convenient to use.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, order of the present invention is to provide the efficient control circuit of SCR of a kind of high efficient and reliable, automatic electricity getting.

To achieve these goals, the technical solution used in the present invention is: the efficient control circuit of a kind of SCR, include resistance R 1, R2, the left end of resistance R 1, R2 connects 5V power supply, right-hand member connects respectively the pin one of optocoupler U1, U2, and the pin two of optocoupler U1, U2 connects respectively the control end of Fire A, FireB; The left end of capacitor C 1, voltage-stabiliser tube D2 connects the pin 4 of optocoupler U1, and the right-hand member of capacitor C 1, voltage-stabiliser tube D2 connects tie point K4; Capacitor C 3, resistance R 3 are connected between tie point K4 and the pin 3 of optocoupler U1; The left end of resistance R 6 connects tie point K4, and the right-hand member of resistance R 6 is connected to respectively the pin one of the left end of voltage-stabiliser tube D3, the lower end of resistance R 2 and switching tube Q2; The pin two of the left end connecting valve pipe Q2 of diode D1, the right-hand member of diode D1 connects tie point K1; The pin 3 of switching tube Q2 connects the right-hand member of voltage-stabiliser tube D3 and the pin two of switching tube Q1; The pin one of switching tube Q1 connects the pin 3 of coupling U1, the left end of the pin 3 contact resistance R4 of switching tube Q1, and the right-hand member of resistance R 4 connects the upper end of G4 and capacitor C 8, and the lower end of capacitor C 8 connects tie point K4; Resistance R 7, R8 connect, and connect respectively the left end of K1 and diode D4, and the right-hand member of diode D4 connects the lower end of diode D5, the lower end of the upper end contact resistance R5 of diode D5, and the upper end of resistance R 5 connects the pin 4 of U1; Resistance R 9, R10 connect, and connect respectively the left end of tie point K2 and diode D7, and the right-hand member of diode D7 connects the upper end of diode D8, the upper end of the lower end contact resistance R13 of diode D8, and the lower end of resistance R 13 connects the pin 4 of optocoupler U5; The left end of capacitor C 13, voltage-stabiliser tube D9 connects the pin 4 of optocoupler U5, and the right-hand member of capacitor C 13, voltage-stabiliser tube D9 connects K1; Capacitor C 15, resistance R 14 are connected between tie point K1 and the pin 3 of optocoupler U5; The left end of resistance R 16 connects K1, and the right-hand member of resistance R 16 is connected to respectively the pin one of the left end of voltage-stabiliser tube D10, the lower end of resistance R 11 and switching tube Q4; 2 pins of the left end connecting valve pipe Q4 of diode D6, the right-hand member of diode D6 connects tie point K4; The pin 3 of switching tube Q4 connects the right-hand member of voltage-stabiliser tube D10 and the pin two of switching tube Q3; The pin one of switching tube Q3 connects the pin 3 of coupling U5, the left end of the pin 3 contact resistance R12 of switching tube Q3, and the right-hand member of resistance R 12 connects the upper end of tie point G1 and capacitor C 14, the lower end tie point K1 of capacitor C 14.

Compared with prior art, the present invention has the following advantages in the present invention:

1) gate pole of SCR control electric current is directly taken from major loop (being electrical network), can strengthen as required or reduce, and has avoided using the restriction of independent current source power, make the conducting of SCR more reliable, and circuit is simple.

2) adopt semiconductor switch pipe, than pulse transformer, operate time is more rapid, the rise time of electric current is also shorter, can make SCR fast by conducting, has reduced switching loss and the caloric value of SCR, and there is no electromagnetic interference, circuit volume and weight also reduces to some extent, has extended useful life.

Accompanying drawing explanation

Fig. 1 is the efficient control circuit overall schematic of SCR of the present invention.

Fig. 2 is the main loop circuit schematic diagram of practical application of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

Referring to Fig. 1, the efficient control circuit of a kind of SCR, includes resistance R 1, R2, and the left end of resistance R 1, R2 connects 5V power supply, and right-hand member connects respectively the pin one of optocoupler U1, U2, and the pin two of optocoupler U1, U2 connects respectively the control end of Fire A, FireB; The left end of capacitor C 1, voltage-stabiliser tube D2 connects the pin 4 of optocoupler U1, and the right-hand member of capacitor C 1, voltage-stabiliser tube D2 connects tie point K4; Capacitor C 3, resistance R 3 are connected between tie point K4 and the pin 3 of optocoupler U1; The left end of resistance R 6 connects K4, and the right-hand member of resistance R 6 is connected to respectively the pin one of the left end of voltage-stabiliser tube D3, the lower end of resistance R 2 and switching tube Q2; The pin two of the left end connecting valve pipe Q2 of diode D1, the right-hand member of diode D1 connects tie point K1; The pin 3 of Q2 connects the right-hand member of voltage-stabiliser tube D3 and the pin two of Q1; The pin one of switching tube Q1 connects the pin 3 of coupling U1, the left end of the pin 3 contact resistance R4 of switching tube Q1, and the right-hand member of resistance R 4 connects the upper end of G4 and capacitor C 8, and the lower end of capacitor C 8 connects tie point K4; Resistance R 7, R8 connect, and connect respectively the left end of K1 and diode D4, and the right-hand member of diode D4 connects the lower end of diode D5, the lower end of the upper end contact resistance R5 of diode D5, and the upper end of resistance R 5 connects the pin 4 of optocoupler U1; Resistance R 9, R10 connect, and connect respectively the left end of tie point K2 and diode D7, and the right-hand member of diode D7 connects the upper end of diode D8, the upper end of the lower end contact resistance R13 of diode D8, and the lower end of resistance R 13 connects the pin 4 of optocoupler U5; The left end of capacitor C 13, voltage-stabiliser tube D9 connects the pin 4 of optocoupler U5, and the right-hand member of capacitor C 13, voltage-stabiliser tube D9 connects K1; Capacitor C 15, resistance R 14 are connected between tie point K1 and the pin 3 of optocoupler U5; The left end of resistance R 16 connects tie point K1, and the right-hand member of resistance R 16 is connected to respectively the pin one of the left end of voltage-stabiliser tube D10, the lower end of resistance R 11 and switching tube Q4; 2 pins of the left end connecting valve pipe Q4 of diode D6, the right-hand member of diode D6 connects tie point K4; The pin 3 of switching tube Q4 connects the right-hand member of voltage-stabiliser tube D10 and the pin two of switching tube Q3; The pin one of switching tube Q3 connects the pin 3 of coupling U5, the left end of the pin 3 contact resistance R12 of switching tube Q3, and the right-hand member of resistance R 12 connects the upper end of tie point G1 and capacitor C 14, the lower end tie point K1 of C14.

The element that main circuit of the present invention is wanted is switching tube, optocoupler, voltage-stabiliser tube, diode, resistance and electric capacity, and SCR is the abbreviation of the controlled brick of semiconductor, and K1, K2 are tie point.Tie point K1, K2 are connected to respectively any two inputs (being electrical network) of major loop, the stack of current limliting by R5, R7～R10, R13 resistance and diode D4, diode D5, diode D7, diode D8, power grid energy is stored in the middle of C1, C13, and voltage-stabiliser tube D2, voltage-stabiliser tube D9 are used for limiting the magnitude of voltage at storage capacitor two ends.Tie point K1, K4 are connected to respectively the two ends of inverse parallel SCR, and wherein tie point K1 gets access to grid, and tie point K4 connects load.Resistance R 2, R6 and R11, R16 are for control switch pipe Q2, Q4.When SCR is not during conducting, tie point K1, tie point K4 two ends must have certain voltage to exist, and directly act on the control utmost point of switching tube through the dividing potential drop of resistance, make it meet the condition of conducting.Otherwise, cannot conducting.Like this, avoid the invalid triggering repeatedly to SCR, can extend the life-span of gate pole.D3, D10 are voltage-stabiliser tube, for the protection of switching tube.Optocoupler U1, U5 are used for control switch pipe Q1, Q3, meanwhile, and also to isolating between signal controlling and major loop.When major loop need be in positive half cycle conducting, need external control system to provide a low level to Fire_D, make the output of optocoupler saturated, then the energy storing in capacitor C 13 can pass through optocoupler, directly act on the gate pole of switching tube, thereby make switching tube Q3 meet turn-on condition, if now switching tube Q4 satisfies condition, SCR conducting.If want, turn-off SCR, the Fire_D that need draw high or open a way, the zero crossing of major loop signal by the time, SCR automatically shuts down.When major loop is during in negative half period conducting, need to control Fire_A, principle is the same.Resistance R 4 is door limit leakage resistance with R12, can select as required.

Referring to Fig. 2, Fig. 2 is main loop circuit figure in practical application.Q1, Q2 are two SCR that inverse parallel connects, and control respectively positive half wave and negative half-wave.G1 is the control utmost point of Q1, the control utmost point that G4 is Q2, and tie point K1 is Q1 negative electrode, and tie point K4 is Q2 negative electrode, and these four points are connected to corresponding point in Fig. 1.

Claims (1)

1. the efficient control circuit of SCR, it is characterized in that, include resistance (R1, R2), the left end of resistance (R1, R2) connects 5V power supply, right-hand member connects respectively the pin (1) of optocoupler (U1, U2), and the pin two of optocoupler (U1, U2) connects respectively the control end of Fire A, FireB; The left end of electric capacity (C1), voltage-stabiliser tube (D2) connects the pin (4) of optocoupler (U1), and the right-hand member of electric capacity (C1), voltage-stabiliser tube (D2) connects tie point (K4); Electric capacity (C3), resistance (R3) are connected between tie point (K4) and the pin (3) of optocoupler (U1); The left end of resistance (R6) connects tie point (K4), and the right-hand member of resistance (R6) is connected to respectively the lower end of the left end of voltage-stabiliser tube (D3), resistance (R2) and the pin (1) of switching tube (Q2); The pin (2) of the left end connecting valve pipe (Q2) of diode (D1), the right-hand member of diode (D1) connects tie point (K1); (Q2) pin (3) connects the right-hand member of voltage-stabiliser tube (D3) and the pin (2) of switching tube (Q1); The pin (1) of switching tube (Q1) connects the pin (3) of coupling (U1), the left end of pin (3) contact resistance (R4) of switching tube (Q1), the right-hand member of resistance (R4) connects the upper end of (G4) and electric capacity (C8), and the lower end of electric capacity (C8) connects tie point (K4); Resistance (R7, R8) series connection, the left end that connects respectively tie point (K1) and diode (D4), the right-hand member of diode (D4) connects the lower end of diode (D5), the lower end of the upper end contact resistance (R5) of diode (D5), the upper end of resistance (R5) connects the pin (4) of optocoupler (U1); Resistance (R9, R10) series connection, the left end that connects respectively tie point (K2) and diode (D7), the right-hand member of diode (D7) connects the upper end of diode (D8), the upper end of the lower end contact resistance (R13) of diode (D8), the lower end of resistance (R13) connects the pin (4) of (U5); The left end of electric capacity (C13), voltage-stabiliser tube (D9) connects the pin (4) of optocoupler (U5), and the right-hand member of electric capacity (C13), voltage-stabiliser tube (D9) connects (K1); Electric capacity (C15), resistance (R14) are connected between (K1) and the pin (3) of optocoupler (U5); The left end of resistance (R16) connects tie point (K1), and the right-hand member of resistance (R16) is connected to respectively the lower end of the left end of voltage-stabiliser tube (D10), resistance (R11) and the pin (1) of switching tube (Q4); (2) pin of the left end connecting valve pipe (Q4) of diode (D6), the right-hand member of diode (D6) connects tie point (K4); The pin (3) of switching tube (Q4) connects the right-hand member of voltage-stabiliser tube (D10) and the pin (2) of switching tube (Q3); The pin (1) of switching tube (Q3) connects the pin (3) of coupling (U5), the left end of pin (3) contact resistance (R12) of switching tube (Q3), the right-hand member of resistance (R12) connects the upper end of tie point (G1) and electric capacity (C14), lower end tie point (K1) (C14).

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