SU490267A1 - Automatic switch - Google Patents

Description

balaclava system 3; plot 15 - at the input of the threshold device 5 (the dotted line indicates the threshold value); plot 16 - at the output of the threshold device 5; plot 17 - pa output circuit "And 6; plot 18 - at the input of the backup generator 10; plot 19 - at the output of the switch.

The switch works as follows.

The pulses of the main generator of the nominal frequency (see Fig. 2) are fed to the trigger 1, where the pulse frequency is divided by 2. The oscillatory system 3 selects the first harmonic of the divided pulse sequence, which is fed to the full-wave rectifier 4. The signal from the rectifier, which is a continuous sequence of half-waves, is fed to the input of the threshold device 5, which generates pulses, the duration of which is determined by the value of the threshold. These pulses are gating for the signals of the main generator. At the nominal tracking frequency, the pulses of the main generator arrive at the AND 6 circuit simultaneously with the pulses of the threshold device, since at resonance the oscillatory system does not create a phase shift and the moment of appearance of the pulses of the main generator corresponds to the moment of zero crossing of the sinusoid emitted by the oscillating system, and the gating pulse is formed by a threshold device in the region of the transition of the sinusoid through zero. The pulses of the main generator pass through the circuit "AND 6, circuit" OR 7 and arrive at the output of switch 11. At the same time, the pulses from the output of circuit "AND 6 are sent to device 8, confirming its condition when the input 10 of the backup generator is disconnected from the circuit" OR 7. The rising edges of the pulses of the threshold device arrive at one input of the NOT circuit 9. Since the second input comes at the same time from output 11, producing a prohibition, the output of the NOT 9 circuit is absent.

The pulses of the main generator with a frequency higher or lower than the nominal one are divided by the trigger 1 by 2 and fed to the oscillatory system 3. Since the frequency of the pulses does not correspond to the resonant frequency of the oscillating system, the phase of its output signal will advance (at a frequency higher than the resonant frequency) or lag (at a frequency lower than resonant), respectively, with respect to the input pulses. Therefore, the pulses at the output of the threshold element will also either be ahead or lag behind the pulses of the main generator. In either case, they will arrive at the “And 6” scheme at different times and there will be no signal at the output. Consequently, it will not be at the output of the circuit “OR 7. Since there is no signal at output 11, it is absent and does not follow the“ NOT 9 ”circuit. Therefore, the falling edge of the threshold device impulse through“ NOT 9 enters device 8, setting it to where the signal from the input 10 of the backup generator is fed to the scheme "OR 7.

Thus, the output of the switch 11 will be a signal of the backup generator. However, the sensing element continues to analyze the signal of the main generator and in the case of restoring its nominal frequency on the output of the “AND 6” circuit, a pulse that arrives at device 8, disconnecting the backup generator from the “OR 7” circuit and through the “OR 7” circuit will pass to the output 11 Work will continue from

main generator.

After a sudden signal disappears from the main generator, at the output of the oscillating system there will be several more periods of damped amplitude sinusoid (like that of a shock excitation circuit), which, after rectifier 4, will go to the threshold device. The pulses from the output of the threshold device arrive at the circuit "And b and" NOT 9. Since the second input of the circuit

“And signal 6 is absent, then there will be no impulses at the output. It will switch to the backup generator, as described in the previous situation. The sensitivity of the switch is determined by

the quality factor of the oscillatory system and the width of the gating pulse of the threshold device, which depends on the threshold value. The narrower the pulses, the smaller the strobe zone, the higher the sensitivity. but

the width of the pulses is limited by the errors of the circuit elements, their aging, the variation of their parameters due to temperature and other destabilizing factors. The minimum width of the pulses should be

such that, with a worse combination of destabilizing factors, the input pulses of the main generator fall into the strobe zone. Pulse width at the output of the circuit "OR

7 should be greater than half the width of the gating pulses in order to confidently implement the ban on the NOT 9.

Subject invention

An automatic switch containing a sensitive element and a switching circuit consisting of a device with two stable states and an AND circuit, to whose input a backup generator is connected, and an OR circuit, whose output is the output of the switch, and from "NOT whose input is connected to the OR circuit, and the output to a device with two

stable conditions, characterized in that, in order to expand the frequency range of the stable operation of the switch, the sensitive element is made of a trigger, an oscillatory system associated with it,

rectifier connected to oscillatory

the system, the threshold device whose input is connected to the rectifier, and the output to the NOT circuit and the first input of the AND circuit, the second input of which is connected to the main generator, and the output to the OR circuit and a device with two stable states .

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