SU1181078A1 - Stabilizing electric power source with current protection - Google Patents

Abstract

POWER SUPPLY POWER SUPPLY WITH CURRENT PROTECTION; -impulse modulator is connected to the input of the current protection comparator, the non-inverting input of which is connected to the output of the saw-tooth generator, and the inverting input is connected to the output of the sensor then ka, characterized in that, in order to increase reliability in case of current overloads and short circuits in the load circuit, the output of the current sensor is connected oppositely with a voltage divider whose output is connected to the inverter input of the current protection comparator g (Lt and the output of the voltage 00 00

Description

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The invention relates to electrical engineering and can be used in power supplies of various radio equipment.

The purpose of the invention is to increase reliability during current overloads and short circuits in the load circuit.

FIG. Figure 1 shows a structural electrical circuit of a stabilizing power supply with current protection; in fig. 2 - diagrams describing his work.

The stabilizing power supply with current protection contains inverter 1, output transformer 2, rectifier 3, filter 4, feedback node 5, pulse-width modulator 6, current protection comparator 7, sawtooth generator 8, the source of the starting voltage current sensor 10 current divider voltage 11.

The power supply with current protection operates as follows.

The sawtooth voltage from the generator 8 is fed to the non-inverting input of the comparator 7. The signal from the current sensor 10 with reverse polarity is fed to the voltage divider 11, where it is added to the output voltage signal and fed to the inverting input of the comparator 7. The modulator 6 compares the pulse from the comparator 7 and the pulse proportional to the voltage duration at the output of the filter 4. The shortest duration of the pulse arrives at the control input of the inverter 1.

When the stabilizing power supply is turned on, when there is no voltage at its output, the modulator 6 generates a pulse of the longest duration, and from the output of the comparator 7 enters the trigger 0782

A pulse whose duration is determined by the angle of inclination of the sawtooth voltage and the voltage level of the source 10 of the trigger voltage. In modulator 6, these two pulses are compared and the smallest pulse arrives at the control input of the inverter 1, as a result of which the output of the stabilizing power source

a voltage appears that is proportional to the duration of the control pulse. This voltage is added on the divider 11 with a current signal that

leads to an increase in the signal at the inverting input of the comparator 7 and an increase in the duration of the control pulse.

This cycle is repeated until

until the control pulse duration begins to be limited by the signal,,. proportional to the voltage at the output of the filter 4.

In case of overcurrent or short circuit at the output of the stabilizing power supply, the amplitude and pulse duration of the collector current of the inverter 1 simultaneously decrease as a result of a comparison at the comparator 7 of the sum of the signal from the current sensor 10 and the output from the filter 4 with sawtooth voltage, filter 4 is reduced when

overloads on. current and short circuit (Fig. 2), where I. is the collector current of the transistors when the stabilizing-power supply is turned on for a short circuit;

BL v -k nominal value

output voltage and collector current; Ujg is the voltage level of the trigger voltage source 9; Ug, 31 - output level

voltage and collector current at overcurrent ..

FIG. 2

Claims (1)

A STABILIZING POWER SUPPLY WITH CURRENT PROTECTION, containing an inverter with an output transformer, a rectifier and a filter, the output of which through the feedback node is connected to the control input of the pulse-width modulator, the output connected to the control input of the inverter, while inhibiting the input of the pulse-width modulator current protection comparator, the non-inverting input of which is connected to the output of a sawtooth voltage generator, and the inverting input is connected to the output of the current sensor, yuschiysya fact 'that, in order to improve reliability at overcurrent and short-circuit n load circuit, a current sensor output is switched oppositely with voltage divider whose output is connected to the inverting input of current comparator Protective you entered and output trigger voltage source. > Fae. 7 1 ¹