SU712965A1 - Redudndancy automatic change-over switch - Google Patents

Description

The invention relates to the field of automation and is intended for use in systems for ensuring the reliability of electronic equipment by duplicating the main channel with an identical channel 5 located in a cold or hot reserve.

Known automatic switches containing a reset circuit, timing circuit and logic elements [1]. 10

The disadvantage of this device is its low reliability.

In addition, there are known automatic reserve switches containing the main and backup channels, isolation 15 devices, detectors, timing chain, key and trigger [2].

The low reliability of this switch is due to the fact that the fault signal 20 is removed from the control output. In this case, in the event of a malfunction, only at the control output does the channel switch, despite the fact that the normal signal remains at the main output of the device. On the other hand, in the event of a malfunction at the main output and a normal signal at the control output, switching does not occur at all. The presence of a control signal input also reduces the reliability of the device 30, since it requires special nodes and circuits.

In order to increase reliability, an automatic switch of the reserve, containing a timing circuit connected to the first input of the trigger, a key whose outputs are connected through the main and backup channels to the output bus and the detector, contains an AND element, an OR element, and an AND-NOT element, the first input which is connected to the first input of the trigger, the second input to the first input of the OR element and the output of the detector, and the output to the second input of the trigger, the second input of the IL14 element connected to the key input and the output of the And element, the first input of which It is connected to the output of the trigger, and the second to the output of the OR element and the third input of the trigger, while the output of the main channel is connected to the input of the detector.

The drawing shows a functional diagram of the device.

The automatic reserve converter contains a timing chain 1, AND — NOT 2 element, OR 3 element, trigger 4, AND 5 element, key 6, main channel 7, backup channel 8, detector 9. The combined outputs of the main and backup channels 7, 8 are the output 10 devices.

The device operates as follows.

When you turn on the supply voltage E _{TT the} signal at the output of the timing circuit 1 corresponds to the logic level “O” for the time determined by the parameters of circuit 1 and then goes into the state of logic “1”. Thus, when the supply voltage is turned on, trigger 4 is priority set on the first input to the logical “O” state at the output. Due to the inertia of the main and backup channels 7, 8 or due to the non-synchronism of switching on the supply voltage of the channels, there may be no signal at the input of the detector 9 at the time of switching on the supply voltage. At the same time, a false fault signal corresponding to logical “1” is generated at the output of detector 9. This leads to the formation at the outputs of the AND – NOT 2 and OR 3 elements of signals corresponding to the logical “1” levels that do not change the state of trigger 4.

At the output of element And 5, a logical “O” signal is generated, according to which key 6 turns on the main channel 7. When the main channel 7 generates an output signal at the output of detector 9, a signal is generated with a level corresponding to the logical “O”, which sets a trigger through OR 3 4 to the state of logical “1” at the output. At the same time, the inputs of the And 5 element receive signals with logical levels “O” and “1”, respectively, and the level of logical “O” is stored at its output.

In case of a malfunction in the main channel 7, a signal is generated at the output of the detector 9 with a level corresponding to the logical “1”. At the output of the AND — NOT 2 element, a logical “O” signal is generated that holds trigger 4 in a logical “1” state at the output. The inputs of element And 5 receive signals with logical levels of “1” and a logical “1” signal is generated at its output, by which a key 6 turns off the main drip 7 and turns on backup channel 8. After that, a logic “ О ”, which does not change the state of trigger 4. The signal from the output of the AND 5 element, corresponding to the logic level“ 1 ”, is fed to the first input of the OR 3 element, excluding the possibility of secondary operation of the key 6. Thus, when the main channel 7 malfunctions its reliable shutdown and inclusion of a reserve key 8.

The device provides reliable inclusion of the backup channel and the disconnection of the faulty main channel 7, which is determined by the signal parameters in the load circuit. The device works automatically, without requiring additional input signals.

Claims (1)

Claim Automatic reserve switch containing a timing chain connected to the first trigger input, a key whose outputs are connected via the main and backup channels to the output bus, respectively, and a detector, characterized in that, to increase reliability, an AND element is entered into it and the element AND –NE, the first input of which is connected to the first trigger input, the second input - to the first input of the OR element and the detector output, and the output - to the second trigger input, the second input of the OR element is connected to the key input and output element AND, the first input of which is connected to the trigger output, and the second - to the output of the OR element and the third trigger input, while the output of the main channel is connected to the input of the detector.