SU1684907A1 - Reserve power amplifier with protection - Google Patents

Abstract

The invention relates to amplifier technology, namely to wired broadcast power amplifiers with hot redundancy, operating on a symmetrical load — and installed on a maintenance-free amplifying center. The purpose of the invention 2 is improving reliability by maintaining the symmetry of the load when the protection is triggered. For this, the redundant power amplifier with protection contains N bridge amplifiers 1, each of which is made on transistors 2. 3, 4, 5, block 6 of excitation, fuses 7, 8, current sensor 9, sensor 10 for example, block 11 of protection power, detector 12 current consumption, driver 13 of the load shedding signal, thyristor 14, 15, diodes 16. 17, 18, 19. Block 6 is made on keys 20, 21. Shaper 13 ASHPO / .POM on the element 24 and waiting for a relaxation generator 25 1 c. P. f-ly, 1 ill.

Description

The invention relates to an amplifier technology, namely a wired broadcast power amplifier with hot redundancy, operating on a symmetrical load (wired broadcast lines - feeders) and installed on an unattended amplifying center.

The purpose of the invention is to increase reliability by maintaining the symmetry of the load when the protection is triggered.

The drawing shows a structural electrical circuit of a redundant power amplifier with protection.

The redundant power amplifier with protection contains N bridge amplifiers 1, each of which is made on transistors 2-5, block 6 of excitation, fuses 7 and 8, current sensor 9, voltage sensor 10, power protection unit 11, current consumption detector 12 the first and second thyristors 14 and 15, the first to fourth diodes 16-19, the block 6 off excitation is performed on the keys 20 and 21, the block 11 protection power power is performed on the element 22 of the comparison and the trigger 23 presetting Vatel disconnecting the load signal 13 is formed on the element 24 and the standby and relaxation oscillator 25.

Redundant power amplifier with protection works as follows.

After the power is turned on, the trigger 23 is set to a single state, i.e. a signal appears on its direct output that unlocks the keys 20 and 21 of block 6, and the signal from the excitation source enters the input of the bridge amplifier 1, the Comparison element 22 determines increment difference of current consumption signals

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current sensor 9 and output voltage from voltage sensor 10. With good transistors 2-5 bridge amplifier 1, the increments of the signals from sensors 9 and 10 are the same, their difference is zero, the trigger 23 does not change its state, and its inverse output contains a signal 0m blocking the operation of the element 24 of the imaging unit 13 information entry.

If the permissible power dissipation is exceeded (decrease in load resistance, phase shift between voltage and current in load), the proportionality of the signal increments is disturbed: large signal increments from current sensor 9 and small signal increments from voltage sensor 10. In this case, the element 22 zeroes the trigger 23, which, on the direct output, switches the keys 20 and 21 of the block 6 to the locked state, i.e. disconnects the input of the bridge amplifier 1 from the excitation source, and on the inverse output removes blocking on the first information input of the AND 24 element (by setting the signal 1). Since the malfunction of the bridge amplifier 1 in this case is caused by external factors, the signal from sensor 9 will correspond to the quiescent current of the amplifier. Therefore, at the output of the consumption current detector 12, the trigger threshold of which slightly exceeds the quiescent bridge amplifier 1 current, there is a signal O that blocks the operation of element 24 on the first information input of the driver 13. In this case, a redundant power amplifier reserve is selected, which continues to operate in nominal mode pause broadcast.

When the external destabilizing factors are eliminated, the signal from element 22 of block 11 removes the zero signal of trigger 23, which is then independently set up at the S input to a single position, i.e. the redundant power amplifier with protection will continue to operate with a reserve, as described above, and without interrupting the broadcast.

In case of failure of one or several transistors 2-5 of the Nth bridge amplifier 1, the proportionality of the increments of the signals from sensors 9 and 10 is disturbed and the power protection unit 11 is triggered, which leads to the disconnection of the input of the bridge amplifier 1 from the excitation source and unlocking on the second information input unit 13 of its element And 24.

However, the current consumption detected by the current sensor 9 greatly exceeds the detection threshold of the detector

12 current consumption, at the output of which signal 1 appears. In this case, element AND 24 permits switching on the generator 25 of unit 13. which produces signals to

unlocking both thyristors 14 and 15. The fuses 7 and 8 are burning out. The damaged bridge amplifier 1 is symmetrically disconnected from the load and does not affect the other amplifiers.

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Claims (1)

Claims 1. Redundant power amplifier with protection, containing N bridge amplifiers, the outputs of which are connected 5 parallel to the symmetrical load, with each of the N bridge amplifiers additionally contains the first and second fuses, and one of the N bridge amplifiers further comprises the first, 0 second, third, fourth diodes, first, second thyristors and a load shedding shaper, the anode of the first thyristor and the cathode of the second thyristor are connected respectively to the positive and mi nus power supply terminals of the bridge amplifier, characterized in that, load when triggered protection, in each of the N bridge 0 amplifiers, an excitation switching unit connected in series to the input amplifier circuit, a voltage sensor connected between the outputs of the bridge amplifier, a consumption current detector, a power protection unit, and the first and second thyristors additionally introduced into each N-1 amplifier , the anode of the first thyristor and the cathode of the second thyristor are connected respectively 0 to the positive and negative terminals of the power supply of the bridge amplifier, the first, second, third, fourth diodes, the current sensor, the driver disconnecting the load, the first and second outputs of which in each 5 of the N bridge amplifiers are connected to control electrodes of the first and second thyristors, respectively; in each of the N bridge amplifiers, the anodes of the first and second diodes are connected to the cathode of the first thyristor, and the cathodes are connected to the outputs of the bridge amplifier and anodes of the third and fourth diodes through the first and second fuses, respectively; the cathodes of the third and fourth diodes are connected to the anode of the second thyristor, while the current sensor is connected between one of the power supply terminals a power amplifier with the same power output of a redundant power amplifier with protection, the output of the current sensor is connected to the first input of the power protection unit and through the current consumption detector to the first input of the load shedding signal generator, the second input of which is connected to the first output of the power protection unit, the second input which is connected to the output of the voltage sensor, and the second output to the control input of the disconnecting device excitation, in this case the shaper of the load shedding signal is made on the series-connected element And and the waiting relaxation generator. 2, The amplifier according to claim 1, wherein the power protection unit is provided on the series-connected comparison element and the pre-installation trigger. From the source