SU1361526A1 - D.c.voltage pulse stabilizer protected against current overload - Google Patents

Abstract

The invention relates to radio electronics and can be used in power supply devices for automation units, computing equipment and communication facilities. The goal is to increase the reliability of the stabilizer. This is achieved by eliminating the effect on the operation of the parasitic voltage fluctuation protection unit on the damping diode 4 by switching on in series with the diode of the peak detector 7 droplets 8, 1 or less. Ipit sc SD

Description

The invention relates to electronics, can be applied in devices for power supply of automation units, computing equipment and communication means and is an improvement of the device according to the author. St. No. 605206.

The purpose of the invention is to increase the reliability of work.

The drawing shows a circuit diagram of a pulsed stabilizer of a constant voltage with protection against overcurrent.

The stabilizer contains a key transistor 1 connected by an emitter to the negative input terminal and a collector to the first output of the 2 droplets of filter 3, the second output of which is connected to the negative output of the terminal, the damping diode 4 connected by the anode to the first output of the chokes of 2 of filter 3, and the cathode with a common bus, capacitor 5 of filter 3, connected parallel to the output terminals of the stabilizer, control unit 6, the output of which is connected to the base of key transistor 1, peak detector 7, consisting of a diode, the cathode of which isdetector 7 and via a throttle 8 is connected to the collector of transistor 1 and a capacitor connected between the common-rail and the anode of the diode connected across the resist ivny .delitel comparing unit 9 to the common bus, the middle point of which is connected to the inverting input of the differential Wuxi

the input of the control unit 6, tiryuush 1st input - with output

the output of which is connected to

a non-inverter element

A delay consisting of a series-connected condenser connected between the common bus and the non-inverting input of the differential amplifier, and a resistor connected between the non-inverting input of the differential amplifier and the cathode of the zener diode, which is connected to the negative terminal of the zener diode,

. The stabilizer works as follows.

After connecting the stabilizer to g, how many orders does the power supply period control the key of detected pulses exceed the power supply period. Output

The voltage of the peak detector 7 is fed to the first input of the block 9 by the transistor 1 is carried out by the control block 6, which ensures the flow through the key transition

Neni, on the second entrance which through

0

five

five

0

five

0

five

0

transistor 1 of such a base current, which, when turned on, transistor 1 keeps it in saturation mode, and when turned off, in cutoff mode; as a result, a pulse voltage is formed at the input of the smoothing filter 3 of the stabilizer, while the voltage pulse amplitude in its flat part is less the voltage of the power source on the magnitude of the voltage drop across the key transistor 1. This same pulse voltage, choke 8, is applied to the input of peak detector 7.

The polarity of each voltage pulse on diode 4 is such that the storage capacitor of the peak detector 6 is charged by the first pulse, and in the process of operation it is recharged. With the appearance of each pulse, the voltage on the diode 4 on the choke 8 produces a self-induced EMF, which prevents the accumulative capacitor of the peak detector 7 from flowing through the charging current for a time determined by the value of the inductance of the throttle - 8, after which the self-inductance of the throttle 8 disappears and the capacitor peak detector 7 is charged to a voltage close to the amplitude of the pulse: at the input of the smoothing filter 3 in its flat part.

Thus, the self-induced EMF arising on the choke 8 when each voltage pulse appears on diode 4, prevents the accumulation capacitor of the peak detector 7 from being charged by short voltage pulses associated with the parasitic oscillations that occur when the diode 4 is turned off, the amplitude of which there may be significantly more power supply voltage. In this case, the inductance of the throttles 8 can be from several units to several tens of microgens and depends on the operating frequency of the stabilizer.

In the span of time, when the key-. the transistor 1 is closed, the storage capacitor of the peak detector 7 is discharged insignificantly, since at the peak detector 7 there is a constant discharge circuit time not changing to the second input of which

31

the delay element 10 and the voltage suppressor 11 supply a voltage reduced by an amount acceptable to the voltage drop on the open key transistor 1. During normal operation of the stabilizer, the voltage drop on the open key transistor 1 is small and the voltage on the first input of the comparison unit 9 exceeds voltage at the second inlet. In this case, there is no signal at the output of the comparison block 9.

An increase in the stabilizer current load causes an increase in the voltage drop across the open key transistor 1, which leads to a decrease in the voltage on the storage capacitor of the peak detector 7 and on the first input of the comparison unit 9. If the voltage at the first input of block 9 becomes less than the voltage at the second input, at the output of block 9, the control voltage, which affects the block 6, is the manager O.Ovs Nnikov Editor P. Gereshi Tehred M.Didps. Corrector S.Cherni

Order 6282/47 Circulation 863 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Design, 4.

61526ki in such a way that the key transistor 1 is locked.

In order to resume the operation of the stabilizer f- after the protection has been activated, it is necessary to disconnect and reconnect the power source.

Thus, switching on the chokes in series with the diode of the peak detector practically excludes the possibility of charging the storage capacitor of the peak detector with parasitic oscillations arising when the damper diode is turned off, which ensures reliable operation of the stabilizer protection circuits, which leads to an increase in the operation reliability total stabilizer as a whole.

Claims (1)

Invention Formula DC switching voltage regulator with overcurrent protection by aut. St. No. 605206, different with that 25 the purpose of reliability of operation, consistent with the diode peak detector included, choke.