SU790303A1 - Two-channel harmonic signal switching device - Google Patents

Description

(54) TWO-CHANNELS HARMONIC SWITCHING The invention relates to electrical measuring equipment and can be used in electronic meters for the relationship of two alternating voltages (logometers), in phase alternators and other devices for alternating current, having a two-channel measuring circuit. To eliminate the errors of two channel devices from non-identity AND instability of paired elements, INCOMING in, different channels, alternate conversion of two signals in a single-channel amplifier-conversion path is used. Alternating signal conversion is performed by an automatic switch controlled by a voltage of more than LOW frequency than the switchable signals. It is a known switching device in which, when the switch is controlled by an independent switching voltage generator, the phase of one or both voltages differs from zero in moments to mutation, which causes a transient process in the amplification and conversion path at each transition. Switching 111 SIGNALS The initial switching phase in the known device depends on the phase shift of the converted signals, AND EXCLUDING OR compensating for the conversion error caused by transients is difficult. Locking (gating) the transducer channel at the time of the transient process increases the measurement time, especially in the measuring amplifier-rectifying paths with a long CONSTANT time. The closest to the proposed technical entity is a two-channel harmonic signal switch that contains a discriminator in each channel, the input of which is connected to the input bus and the output to the first input of the AND element, the output of which is connected to the input of the counting trigger, the single output of which is connected to the control input of the key of another channel, the information inputs of the keys are connected to the corresponding INPUT buses, and the outputs are connected to the output bus, the control trigger, the outputs of which are connected to the second input Odam elements And, and the counting input is connected to the output of the forming one-shot.

serially connected first and second time specifying one-shot 2.

The disadvantage of this device is the presence of two time setting elements (one-shot), which causes the inequality and instability of the half-periods of the switching of harmonic signals.

The purpose of the invention is to improve the accuracy of switching.

This goal is achieved by the fact that, in a two-channel harmonic signal switch, there is a discriminator in each channel, the input of which is connected to the input bus and the output to the first input of the And element, the output of which is connected to the input of the counting trigger, the single output of which is connected to the control input the key of the other channel, the information inputs of the keys are connected to the corresponding input buses, and the outputs are connected to the output bus, the control trigger, the outputs of which are connected to several inputs of the AND elements, and the counting input d is connected to the output of the forming one-shot one-shot, serially connected first and second time setting one-shot, two OR elements are introduced, the inputs of the first OR element are connected to the single outputs of the first and second channel triggers, and the output is connected to the input of the first time of the setting one-shot, the output of which is connected to the third inputs of the AND elements, the output of the second time of the master single vibrator is connected to the quarter-quarter inputs of the AND elements, the inputs of the second OR element are connected to the zero outputs of the first and second trigger points th channel, and the output is connected to the input of one-shot formiruk Oleg Zhegoyev.

The drawing shows a functional diagram of the device.

The device consists of two discriminators 1 and 2, the first 3 and second 4 times of master single vibrators, which form the single vibrator 5, the trigger 6 of the first channel, the trigger 7 of the second channel, the control trigger 8, two elements 9 and 10, two keys 11 and 12, two elements OR 13 and 14.

The principle of the device is as follows.

In the initial state, all the device triggers are set to the zero state, and at the output of one-shot 3 and 4, the unit levels of april act. Since unit I levels are at all outputs of AND 9, it is open, and element 10 is closed by zero voltage of trigger 8 at the input connected to the single output of trigger 8. This allows one of the pulses to pass

through the open element AND 9 and set the trigger b to the single state. The signal from the single output trig, the trigger through the element OR 13 starts the one-shot 3. At the same time, the voltage level changes

at one of the inputs of the element 9, the field of which the further passage of pulses from the output of the discriminator 1 to the counting input of trigger b stops.

After time C of the one-shot 3 returns to its original state and, by protecting the front of its output pulse, it starts the one-shot 4. The levels at the inputs of the And 9 element connected to the one-shot 3 and 4 are reversed and it is still closed.

After time, the one-shot 4 returns to the initial state, the element AND 9 opens and the pulse from the output of the discriminator 1 returns the trigger b to the zero state. The voltage drop from the zero output of the trigger 6 through the element OR 14 starts the one-shot 5, the output short pulse of which sets the trigger 8 to the one state. From this point on, element And 9 closes, and element And 10 opens, and the considered half-cycle of operation of the device is repeated.

The switching point of the trigger 7 in the I zero state is restarted by the one-shot 5, the output pulse of which the trigger 8 is again set to the zero state. From this moment, the element 10 is closed, and the element 9 opens, and with the arrival at the counting input of the trigger 6 pulse from the discriminator 1, the considered full cycle of operation of the device is repeated.

From the considered principle of operation of the device, it can be seen that the switching of the flip-flops 6 and 7 is carried out by pulses corresponding to the moment; transitions of the compared signals through-zero. This means that the output signal of the switching device in each clock cycle of the 1st mutation begins, and ends with a zero initial phase. At the same time, the duration of half-periods of co lution –1 + Cr is determined by one time as a setting element (one-shot 3 and 4, and therefore the long-term instability of half-periods of switching is absent, and the short-term almost does not affect the accuracy of switching. of the original one-vibrator state. When two single-vibration oscillators are turned on, one recovery occurs at the moment when

Claims (1)

Claim A two-channel harmonic signal switch containing a discriminator in each channel, the input of which is connected to the input bus, and the output is connected to the first input of the And element, the output of which is connected to the input of the counting trigger, the single output of which is connected to the control input of the key of another channel, information inputs of keys connected to the corresponding input buses, and the outputs are connected to the output bus, a control trigger, the outputs of which are connected to the second inputs of the AND elements, and the counting input is connected to the output of the forming one an oscillator, connected in series by the first and second time-generating single vibrators, characterized in that, in order to improve the switching accuracy, two OR elements are introduced into it, the inputs of the first OR element are connected to the unit outputs of the triggers of the first and second channels, and the output is connected to the input the first timing one-vibrator, the output of which is connected to the third inputs of AND elements, the output of the second timing one-vibrator is connected to the fourth inputs of AND elements, the inputs of the second OR element are connected to zero outputs triggers the first and second channels, and an output connected to an input forming od15 novibratora.