SU1091341A1 - Redundant pulse sequence generator - Google Patents

Abstract

BACK-UP SEQUENCE GENERATOR AND P1ULSES, contains cautjiH the first and second pulse sequence generators, the outputs of which are connected by the inputs of the first and second elements AND, the outputs of which are connected to the output bus of the device and through the reset signal generation unit to the reset input of the counter, the communication unit, output which is connected to the second inputs of the first and second elements And, and with the first group of inputs of the display element, the second group of inputs of which is connected to the outputs of the first and second g pulse sequence nebulizers, characterized in that, in order to eliminate relaxation switchings to the reserve, which occur when the main generator goes into intermittent generation, and increases reliability due to this, an additional pulse counter and an additional OR element are introduced, and the output of the second sequence generator pulses connected to the counting input-additionally (L C th counter, the output of the block forming the reset signal is connected to the reset input of the additional counter, high voltage dy counters through an additional element OR connected to the input of the switching unit. D): about

Description

The invention relates to a pulse technique and can be used in digital measuring devices in computer control devices as a master clock pulse frequency generator, which requires the generation of electrical oscillations with increased reliability and control.

A redundant pulse sequence generator is known, containing two identical pulse generators (relaxers) and a generator control and switching circuit that, in the event of a generator failure, operating as a main generator, connects to the output circuits of the backup generator device f,

A disadvantage of the known device is the low reliability associated with the need for fine tuning of the analog nodes of the device.

The closest in technical terms to the present invention is a redundant pulse sequence generator containing the first and second pulse sequence generators, the outputs of which are connected to the first inputs of the first and second AND elements, whose outputs through the OR element are connected to the output bus of the device and through the signal generation unit reset with the reset input of the counter, switching unit, the outputs of which are connected to the second inputs of the first and second And elements and to the first group of inputs of the indicator element This second group of inputs is connected to the outputs of the first and second: 2J pulse train generators.

The disadvantage of this device is the relaxation of the OHOHiiix switch to the reserve in it in case of emergency frequency reduction of the main generator or the transition of the main generator to intermittent operation. Such a mode may occur, for example, if there is a poor-quality contact in the connections of the elements of the main generator.

The purpose of the invention is the elimination of relaxation switchings to the reserve, which occur when the main generator switches to intermittent generation, and thereby increases reliability.

The goal is achieved by the fact that V is a reserved pulse sequence generator containing the first and second pulse sequence generators, the outputs of which are connected to the first inputs of the first and second And elements, the output of which is connected to the output bus of the device through the W) and the reset signal generating unit to the input reset the counter, the switching unit, the outputs of which are connected to the second inputs of the first and second And elements and to the first input group of the display element, the second group of inputs of which о is connected to the outputs of the first and second generators of the pulse sequence, an additional pulse counter and an additional element 1β are added, the output of the second generator of the pulse sequence is connected to the counting input of the additional counter, the output of the reset signal generating unit is connected to the reset input of the additional counter, the outputs of the counters through the additional element OR connected to the input of the switching unit.

Fig, 1 shows a functional diagram of the device; Fig, 2 timing diagrams illustrating the operation of the device.

The reserved pulse train generator contains the first and second pulse generator 1 and 2 pulse sequences, the outputs of which are connected to the first inputs of the first and BTopo.ro elements 3 and 4, the output of the first generator is connected to the counting input of counter 5, the output of the second generator is connected to the counting input an additional counter 6, the outputs of the elements And are connected to the inputs of the element SHTI 7, the outputs of the counters through an additional element OR 8 are connected to the input of the switching unit 9, the output of the element ШШ 7 is connected to the output bus of the device The properties and with the input of the unit 10 to form a reset signal, the outputs of the generators and the switching unit are connected to the inputs 1 I of the display.

The redundant pulse sequence sequence generator operates as follows.

Generators i and 2 pulses form a sequence of pulses. 3 repetition frequency of which is the same and equal to the frequency that must be obtained at the output of the device. The sequence of 1 pulses from the output of the generator 1 is fed to the first input of the first element I 3 and to the counting input of the counter 5. Similarly, the pulses from the output of the generator 2 are fed to the first input of the second element I 4 and to the counting input of the additional counter 6. The switching unit 9 of the pulse generators can be executed, for example, in the form of a trigger with a counting input. Depending on which position the trigger was set at when the device was turned on, one of the first outputs of the trigger - on the second input of one of the elements AND 3 or 4 there will be an enabling signal. Accordingly, on the other element And at its second input there will be a prohibiting signal. Suppose that the permissive signal in our example is fed to the second input of the first element AND 3 Then the pulses from the output of the generator 1 through the element 3 and the element RSHI 7 are fed to the output of the device. Simultaneously, the pulses from the output of the generator 2 are sent to counters 5 and 6 after a cool-down) 5 (day through the IZ element, the l-LTIH 7 element and block 10 as counter-zeroing pulses. Thus, with the help of the counter 5, each one is automatically monitored). impulse from generator 1, and with the help of counter 6 - after each impulse at the output of generator 2. If, due to a malfunction, generator 1 stopped working after a certain time, the zero signals from the output of unit 10 will no longer flow to the corresponding inputs 5 and 6. Due to the fact that generator 1 does not work anymore, counter 5 remains in its initial state (or in the state in which it turned out to be at the moment the fault occurred). Counter 6 continues to count the incoming pulses at its input from the output of the generator 2. Counters 5 and 6 are expedient to be performed consisting of two bits and turn them on so that after the pulse of zeroing of the counters disappears, the next pulse arriving at the counting input of the counter connected to the sound pulse generator, overflow l this counter and with his vy414 x The ode passed to the element 1-SHI 8. In this case, the input of the block 9 is switch-. pulse generators will receive a control signal by which element 3 will be closed, and at the second input of element 4 it will allow the 1st signal to be resolved. After that, the signals from the generator output 2 pulses will begin to flow to the device output and through block 10 as zeroing signals to the corresponding inputs of counters 5 and 6. (In Fig. 2, the time of generator I failure is indicated by M, and the time when generator 2 starts up, mr Element 11 of the indication of the operation of the generators 1 and 2 pulses does not affect the operation of the entire device. Its presence in the composition of the device allows one to see which of the generators is working or not working due to a malfunction, and which of the generators is currently time in The main device (and operates at the output of the device), and which is a backup. The display can be carried out, for example, by means of LEDs. The circuit of the proposed device is made symmetrically, and the generators 1 and 2 are in equal conditions. the generator is randomly selected depending on the installation in one of the possible states of the switching unit 9. At the output of the device and to the input of the driver 10 reset pulses. impulses come from this main generator. When switching to a reserve, when a temporary failure occurs and the main generator operates, this generator becomes a backup and the other main generator. Thus, the device automatically selects the most stable generator. The symmetry property of the proposed device is a significant advantage over the known one. Indeed, cases of complete failure of the generator, such as quartz, are extremely rare. In practice, generator failures are usually manifested as a transition to a discontinuous generation mode, or a sharp decrease in the frequency of the generated pulses. Such failures can occur, for example, during mechanical vibrations, when operating on a device, under extreme thermal conditions.

paOOTbi generators, with poor-quality contacts between the circuit elements of the generator. For a known device in which one of the generators is the main one, always switching the main generator to the discontinuous generation mode will cause relaxation switching to the reserve in the device and back.

those. to the failure of the entire device, regardless of the presence of a working backup generator. In the proposed device, such relaxation will not occur, because its scheme is symmetrical, and the controlled pulse sequence does not come from one of the generators, as in the known device, but from the output of the device.

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FIG. 2

Claims (1)

RESERVED PULSE SEQUENCE GENERATOR, contents of the first and second pulse train generators, the outputs of which are connected by the inputs of the first and second AND elements, whose outputs are connected via the OR element to the device output bus and through the reset signal generating unit with the counter reset input, the switching unit, outputs which is connected to the second inputs of the first and second elements And and to the first group of inputs of the indication element, the second group of inputs of which is connected to the outputs of the first and second torus sequence of pulses, characterized in that, in order to exclude relaxation switching to the reserve that occur when the main generator goes into intermittent generation, and increase due to this reliability, an additional pulse counter and an additional OR element are introduced into it, and the output of the second sequence generator pulses are connected to the counting input of the additional counter, the output of the reset signal generating unit is connected to the reset input of the additional counter, the outputs of the counters are ithout an additional OR gate connected to the input of the switching unit. I 091341