SU1188851A1 - Audio-frequency power amplifier with protection - Google Patents

Abstract

LOW-FREQUENCY POWER AMPLIFIER WITH PROTECTION containing a coincidence element, delay element, executive unit, first and second amplification channels whose first inputs are respectively the first and second inputs of a low-frequency power amplifier with protection, connected in series the first comparator, the first trigger and the first display unit and a second comparator, a second trigger, a second trigger and a second display unit, connected in series, the second input of the first trigger connected to the second input of the second trigger, output the delay element and the first input of the coincidence element, the second input of which is connected to the output of the first trigger, the third input to the output of the second trigger, and the output to the input of the execution unit, which in order to simplify the device, the output of the first gain channel is connected to the common bus low power amplifier with protection through the first circuit of the series-connected first and second resistors and the first capacitor, the connection point of the first and second resistors connected to the second input of the first the gain channel, and the connection point i of the second resistor and the first capacitor to the input of the first comparator (L ra, the output of the second gain channel is connected to the common bus of the low-frequency power amplifier with protection through the second circuit of the third and fourth resistors connected in series and the second capacitor, This connection point of the third 00 00 00 and fourth resistors is connected to the second input of the second channel amplified. Nor, and the connection point of the fourth ate resistor and the second capacitor to the input of the second comparator.

Description

This invention relates to radio engineering and can be used in high power transistor amplifiers.

The purpose of the invention is to simplify the device.

The drawing shows an electrical functional scheme of the proposed low-frequency power amplifier with protection.

The low-frequency power amplifier with protection contains first and second amplification channels 1 and 2, first and second comparators 3 and 4, delay element 5, first and second triggers 6 and 7, first and second indication blocks 8 and 9, coincidence element 10, and executive block 11, the first, second third and quarter resistors 12-15, the first and second capacitors 16 and 17

The power amplifier works as follows.

When the power is turned on using the delay element 5, the triggers 6 and 7 are reset and the actuation of the execution unit 11 is delayed by the time required to complete the transients in the preliminary stages of the first and second channels 1 and 2 of the amplification.

During normal operation, the voltage on the first and second capacitors 16 and

17 is close to zero, and the executive unit 11 does not affect the operation of the first and second amplification channels 1 and 2. When a constant voltage appears at the output of the first or second channels 1 and 2 amplifiers, it triggers the first or second comparators 3 and 4, the first or second triggers 6 and 7, and the execution unit 11, which disconnects the supply voltage from the first and second second channels 1 and 2 gain. The first or second blocks 8 and 9 of the display will show the number of the faulty gain channel.

A low-frequency power device with protection can be made multi-channel. In this case, it must be supplemented with comparators, triggers, indication blocks, and the number of inputs in the coincidence circuit must be increased.

The first, second, third, and fourth resistors 12-15, the first, second capacitors 16, and 17, are designed to impart a constant component to the inputs of the first and second comparators 3 and 4 and simultaneously perform the function of a negative feedback circuit spanning the first and the second channels 1 and 2 gain.

§

r

p.

c

lO

P

15

Claims (1)

LOW FREQUENCY POWER AMPLIFIER WITH PROTECTION, comprising a matching element, delay element, executive unit, first and second amplification channels, the first inputs of which are respectively the first and second inputs of a low-frequency power amplifier with protection, connected in series to the first comparator, the first trigger and the first display unit as well as series-connected the second comparator, the second trigger and the second display unit, while the second input of the first trigger is connected to the second input of the second trigger, the output element and the delay and the first input of the coincidence element, the second input of which is connected to the output of the first trigger, the third input - with the output of the second trigger, and the output with the input of the executive unit, characterized in that, in order to simplify the device, the output of the first amplification channel is connected to a common the bus of the low-frequency power amplifier with protection through the first circuit of series-connected first and second resistors and the first capacitor, while the connection point of the first and second resistors is connected to the second input of the first channel ia, and the connection point of the second resistor and the first capacitor is connected to the input of the first comparator, the output of the second amplification channel is connected to the common bus of the low-frequency power amplifier with protection through the second circuit from the third and fourth resistors and the second capacitor connected in series, while the connection point of the third and the fourth resistor is connected to the second input of the second amplification channel, and the connection point of the fourth resistor and the second capacitor with the input of the second comparator. > 1 1188851 2