SU1141544A1 - Device for control of transistor switch - Google Patents

Abstract

DEVICE TO CONTROL transistor switch comprising a cascade control with an output transistor that is connected via a capacitor to the input of the transistor switch, and .tranzistor connected across the output of the control stage, characterized in that stselyu increasing efficiency of the control in the collector circuit of the output transistor A cascade connected in series is a non-choking choke and a diode, in parallel with which a capacitor is connected.

Description

The invention relates to electrical engineering and can be applied in devices for regulating and converting direct current into alternating current, in particular, in circuits with increased requirements for the speed of a power transistor switch. A device for controlling a transistor switch in an inverter, made according to a scheme that provides for the firing of the power transistor, and contains a power transistor with a transformer output to the load, a control transistor loaded through a current limiting resistor and a forcing capacitor to the input of the power transistor, a transistor switch, is enabled, and the transistor switch is switched on, the transistor switching resistor and the forcing capacitor to the input of the power transistor, the transistor switch, is switched on, the transistor switch is loaded, and the driving transistor is loaded by a current limiting resistor and forcing capacitor to the input of the power transistor, the transistor switch is switched on, and the transistor switch is switched on, and the load transistor is loaded by the current limiting resistor and forcing capacitor to the input of the power transistor. input circuit of the power transistor. The circuit provides a forced on and off of the power transistor O. However, the formation of the turn-on is provided by the forcing capacitor, and the forcing is locked by the transistor key. The presence of a current limiting resistor in the base circuit of the power transistor causes additional active power losses along the control circuit and reduces efficiency. Closest to the invention is a device for controlling a transistor switch, containing an equalizing stage with an output transistor, connected via a split capacitor to the input of a transistor key, and a transistor connected in parallel with the output of the control stage G2. However, the known circuit contains in the base circuit a current-limiting resistor connected in parallel with the coupling capacitor. The use of a current limiting resistor in the base circuit of a power transistor increases the power loss and reduces the PDC. The aim of the invention is to increase efficiency. The goal is achieved by the fact that a device for controlling a transistor switch, containing a control stage with an output transistor, connected via a split capacitor to the input of a transfer switch, and a transistor connected in parallel with the output of the control stage, to the output collector circuit the transistor of the control stage is connected in series with the input of unsaturation with the choke and the diode, in parallel with which a capacitor is connected. The drawing is a schematic diagram of the device proposed va. In the device, the output transistor 1 of the control stage is connected to the transistor 2 and the separation capacitor 3. The control stage load is the input of the power transistor 4 with the output terminal 5. An unsaturated choke 6 and a diode 7 are connected in series to the collector circuit of the transistor of the control stage and in parallel the capacitor 8 is turned on. The circuit has control inputs 9 and 10, to which control signals in the form of square impulses are shifted relative to each other by 180 el. The scheme works as follows. The anti-phase control pulses are fed in in-phase to the inputs 9 and 10 of the control stage and the transistor switch. The positive control impulse arriving at Id 9 turns on transistor 1, while the capacitor 8 discharges along the circuit: collector-emitter junction of transistor 1 - capacitor 3 - base-emitter junction of transistor 4 - power source. Throwing the discharge current of the capacitor 8 provides a forced turn on of the transistor 4. The capacitor 8 is completely discharged and then recharged with the opposite polarity indicated in the brackets. The base current of the power transistor 4 and the capacitor 3 rises, changing according to a harmonic law, determined mainly by the parameters L and C of the throttles 6 and the capacitor 8. The parameters L and C are chosen on the basis that during the whole time of the control pulse at the input 9 The base current is sufficient for reliable unlocking of the transistor 4 and does not change its direction. Upon termination of the control pulse at the input 9, the control transistor 1 closes and the energy accumulated in the inductance of the throttle 6 recharges the capacitor B. Thus, the capacitor 8 acquires the charge necessary for

unlocking elements of active transis

torus 4 in the next cycle, its on-resistance allows significantly)

neither Transistor switch 2 includes-. Increase the overall efficiency of the device. Besides

c in antiphase transistor 1, and, therefore, devices-6 allows to obtain

In this case, the capacitor 3 is partially discharged;

pyranium of the power transistor 4, and os - by discharge of a capacitor, the accumulated charge of the capacitor 3 energy loss. Thus, reduced to

bakes active transis-minimum locking dynamic losses in the process

torus 4 with an open transistor junction of the power transistor that

re 2. additionally increases the overall efficiency.

Claims (1)

DEVICE FOR CONTROLLING A TRANSISTOR KEY, containing a control stage with an output transistor connected through an isolation capacitor to the input of a transistor switch, and a transistor connected in parallel with the output of the control stage, characterized in that, to increase the efficiency, the collector circuit of the output Transistor of the control stage introduced unsaturated inductor and diode, in parallel with which a capacitor is connected.