SU1305843A1 - Transistor switch - Google Patents

Abstract

The invention relates to the field of electrical engineering and can be used in pulsed current control devices, for example, in frequency and voltage controllers of direct current electric machines. The purpose of the invention is to increase the efficiency and expansion of functional capabilities. The device contains a key transistor 3, a converter cell 4 of the power current of a magnet-transistor converter, the input valves of which are bridged by a capacitor 5, a control circuit 6, an input sensor 7, a power source 1, a load 2, a ballast resistor 8 converter cell power current magnetic transistor converter. A transducer cell 9 of the no-load current, which is made on transistors in a push-pull pattern, is introduced into the device. Scheme 6 (L SdE ate 00 yy 00

Description

1305843 control contains a transistor And, laziness will allow to increase the range

capacitor 13, diode 12. Introduction to the device of additional elements, as well as a new one. Execution of the control circuit of the load current and limit the degree of our performance of the key transistor, 2 hp f-ly. 1 il.

one

The invention relates to electrical engineering and can be used in pulsed current control devices, for example, in frequency and voltage controllers of ac power electric machines.

The purpose of the invention is to increase the efficiency and enhance the functionality by increasing the range of control of the load current and limiting the degree of saturation of the current transistor.

The drawing shows a circuit diagram of a transistor switch.

The transistor switch contains the power source 1, the terminals of which are connected in series with the load 2, the collector-emitter junction of the key transistor 3 and the input terminals of the transducers of the power current D cell of the magnet-transistor converter, shunted by the capacitor 5, the output terminals of the power current transducer magnetic a transistor converter is connected to the power terminals of the control circuit 6, the output circuit of which is connected to the electrodes of the key transistor 3, and the input circuit connected to the input signal sensor 7, a ballast resistor 8, a converter cell 9 of the no-load current, made on transistors on a push-pull circuit, the output winding of which is located on the common magnetic circuit of the output transformer 10 of the converter cell 4 of a power current of a magnetic-transistor converter 9 no-load currents through the ballast resistor 8 are connected between the collector and the emitter of the key trap 3; laziness will increase the range

regulating the load current and limit the degree of the key transistor, 2 Cp. f-ly. 1 il.

five

fO

15

20

25

thirty

35

40

torus 3 or between the positive terminal of the power source and the positive terminal of the sensor 7 input signal.

The transistor switch control circuit 6 includes a transistor 11 whose collector-emitter junction is connected between the positive power terminal of the control circuit and the base of the key transistor 3, a capacitor 12 that is connected between the positive power terminal of the control circuit and the emitter of the key transistor 3, diode 13, anode which is connected to the positive power terminal of the control circuit, and the cathode - to the collector of the key transistor 3,

Also, the dp of the power supply of the input signal sensor 7, the input terminals of the converter cell 9 of the no-load current through the ballast resistor 8 can be connected between the positive terminal of the power supply 1 and the positive power terminal of the input signal sensor 7.

Transistor key works as follows.

When the key transistor 3 is open, the supply voltage across the input - terminals of the converter cell 9 of the no-load current is low, since the voltage drop at the junction of the collector-emitter of the key transistor 3 is minimal. The entire load current 2 flowing through the open key transistor 3 is supplied to the input terminals of the conversion cell 4 of the power current of the magneto-transistor converter, the output current of which is fed to the power terminals of the control circuit 6, which provides the unlocking of the key transistor 3 .

With the open key transistor 3, the power supply current of the control circuit 6 flows through the collector-emitter junction of the open transistor 1 to the base of the key transistor 3 and through the diode 13 to the collector of the key transistor 3.

Branch part of the input current of the control circuit 6 to the collector of the key transistor 3 reduces the magnitude of the base current of the key transistor 3 and thereby limits its saturation. At the moment of locking the transistor 11, the entire power supply of the control circuit 6 flows through the diode 13 to the key collector transistor 3 during the absorption time of minority charge carriers in it. Due to this, a charge (minor current carriers) accumulates on the p-p junction of the diode 13, which, when the key transistor 3 is locked, provides for the flow of the charging capacitor 12 through it during the recovery time of the reverse resistance of the diode 13, and maintains a low voltage on the collector transistor 3. Thus, the short duration of the flow of a large direct current through the diode 13 reduces the losses in the circuit as compared with the known device, where the direct current flows through the diode during the total time of the open state of the key transistor.

Also at the moment of unlocking the transistor 11, the base current of the key transistor 3 is forced due to the discharge of the capacitor 12, which reduces the unlocking time of the key transistor 3 and reduces the dynamic losses, than the most.

When the key transistor 3 is closed at its collector-emitter junction, the voltage drop is almost equal to the voltage of the power source 1. Through the ballast resistor 8 flows the supply current of the converter cell 9 of the no-load current. Since the voltage drop on the converter cell 9 of the no-load current can be selected greater than on the converter cell 4 of the power current of the magnetic-resistor converter by selecting the 9 9 W of its windings, then getting the same power on you

five

0

During the transistor switch, less power is required flowing through the ballast resistor 8, so that the power losses in the ballast resistor 8 can be reduced and the control range of the load current 2 can be extended to reduce the minimum load current 2,

Claims (3)

O Formula of a, b ete n and 1, A transistor switch containing a power source to which terminals are connected in series with a load, a collector-emitter junction of a key transistor and input terminals 1-I) 1 of a current transformer cell of a magnetically-transistor conversion, a capacitor-biased output terminal of a power converter cell the magnet-transistor converter is connected to the power terminals of the control circuit, the output circuit of the control circuit is connected to the electrodes of the key transistor, and The bottom circuit is connected to an input signal sensor, a ballast resistor, characterized in that, in order to increase efficiency and expand functionality, a no-load current converter cell is introduced, which is made on transistors according to a two- and 5-stroke circuit, the output winding of a no-load current converter cell located on the common magnet - the conductor of the output transformer of the converter cell of the power current of the magnet-transistor converter; the input terminals of the converter cell of the current are single The path through the ballast resistor is connected between the collector and the emitter of the key transistor or between the positive terminal of the power source and the positive terminal of the input signal sensor. 0 0 five 2, The key according to claim 1, wherein the control circuit comprises a transistor, the collector-emitter junction of which is connected between the positive power terminal of the control circuit and the base of the key transistor. 3.Klyu on PP, 1 and 2, characterized in that, with the aim 513058436 limiting the degree of na- tionalisciode to the collector of the key transistor, the control circuit of the transistor, the capacitor is switched on contains a capacitor and a diode, the anode between the positive power terminal of which is connected to the positive control circuit and the emitter of the transistor.