SU721758A1 - Ac voltage monitoring arrangement - Google Patents

Description

The invention relates to electrical engineering. The device can be used to determine the deviation of the voltage of electrical energy.

Known voltage control devices containing comparison devices and logic and pulse elements [1]. Such devices are not suitable for controlling alternating voltages.

It is also known control device ₁₀ variables over- voltages, comprising two comparison device whose inputs are connected together and serve as an input control device, their other inputs are the reference input, and two switches whose inputs are sub-keys ₁₅ to the output of the comparator [ 2J, The disadvantage of this device is the low speed; The measurement time in Yem is equal to one input signal period.

The aim of the invention is to increase _and speed of the device.

This goal is achieved by the fact that in the device for controlling variable voltages, containing two comparison devices, the inputs of which are interconnected and serve as inputs of the control device, their other inputs serve as inputs of the reference voltage, and two keys whose inputs are connected to the output of one comparison device, two multivibrators, two triggers and an And element are introduced, and the output of the other comparison device is connected through multivibrators to the control inputs of the keys and directly to the zero inputs of the triggers, the outputs are the key connected to the unit inputs of the triggers, respectively, the zero outputs of the triggers are connected to the inputs of the element I.

The drawing shows a block diagram of a device for monitoring variable voltages.

In the initial state, the input signal is supplied to the comparison devices 1 and 2. The output of the comparison device 1 through multivibrators

3.4 is connected to the inputs of the keys 5, 6, to the second inputs of which a comparison device 2 is connected. The outputs of the keys are connected to the single inputs of the RS-triggers 7 and 8. The zero outputs of the RS-triggers are connected to the inputs of the And 9 element.

The sinusoidal voltage reaches the value of a certain voltage level Ug in time, 1. Up t _x arc ynp-g-hlt-5

If the test voltage has a nominal value of U _H , then it reaches the level of U _o after a time £ θ. If the voltage is equal to the maximum allowable and _n + d1), then it reaches 10 level U _o after a time of 17 j. The voltage Ux ^{= u} xm ^{sir, a> t} x 'is ^{greater than the} permissible value U _H + Δ U, reaches the level U _o after a time shorter than''j. a voltage less than the permissible ^ U _H - Δ U, - for a time greater than ^.

The pulse duration of the multivibrator 3 is set equal to the time Cj, and multi-, vibrator 4 - equal to 17 ^.

The tested sinusoidal voltage _{20 is} supplied to the inputs of the comparison devices 1 and 2. When the sinusoidal voltage U _x passes through a zero value, a pulse appears at the output of the comparison device 1, which sets the RS-triggers 7 and 8 to zero and starts the multivibrators 3 and 4 controlling the operation of electronic keys 5 and 6.

When the investigated voltage U _x reaches the value of U _on, the comparison device 2 is triggered. In this case, there may be the following 30 cases.

If the test voltage is greater than the permissible value of P _n + Δ U, then the pulse at the output of the comparator 2 sets the RS trigger 7 to the state “1”, the trans lights up; Porant '' Over the norm. ”

If the voltage is less than the permissible · Ι ^, - ΔΙΙ, then the pulse from the comparator 2 arrives after a time> ^ 2- The key 6 is open and the RS-trigger 8 is set to state 1;

Ec 'and the test signal does not go beyond the permissible U _H t Δ U, then both electronic keys are closed and the triggers remain in zero states. The signal “Norma” is issued to the control system through the And 9 element.

To quantify the signal under study, it is necessary to measure the time interval between the output pulses of the comparison circuits 1 and 2. The amplitudes of the signal under study are determined from the expression

Xttl bin οοί _χ

Such a control device has a high speed (parameter control time is less than a quarter of the input signal period), in addition, it allows a quantitative assessment of the measured voltage.

Claims (2)

This invention relates to electrical measuring technology. The device can be used in determining the voltage deviation of electrical energy. Voltage monitoring devices are known that contain comparison devices and logic and pulse elements 1. Such devices are not suitable for monitoring variable voltages. It is also known a device for controlling alternating voltages, containing two comparison devices, whose inputs are interconnected and serve as an input for a monitoring device, their other inputs serve as voltage reference inputs, and two keys, whose inputs are connected to the output of a single comparison device 2, the disadvantage of this the device is a short time action; the measurement time in it is equal to one period of the input signal. The aim of the invention is to increase the speed of the device. This goal is achieved by the fact that the device for controlling variables, including two comparison devices, the inputs of which are interconnected and serve as inputs of the control device, the other inputs of them are inputs of reference voltages, and two keys whose inputs are connected to the output of one device comparison, two multivibrators, two triggers and an AND element are introduced, and the output of the other comparator device is connected via multivibrators with uglavlyuyuschim key inputs and directly with zero trigger inputs, key outputs it is connected to the single inputs of the flip-flops, respectively, the zero outputs of the flip-flops are connected to the inputs of the element I. The drawing shows a block diagram of a device for monitoring variable voltages. In the initial state, the input signal is fed to the comparison devices 1 and 2. The output of the comparison 1 device through multivibrators 3.4 is connected to the inputs of keys 5, 6, the comparator 2 device is connected to the second inputs. The outputs are connected to the single inputs of the RS flip-flops 7 and 8. The zero outputs of the RS-flip-flops are connected to the inputs of the And 9 element. The sinusoidal voltage reaches the value of a certain voltage level UQ through time, i. Uo t uj sin 71- If the voltage under test has a nominal value of Id, then it reaches the level UQ after time e. If the voltage is equal to the maximum allowable, then it reaches the level DO through time Cj. Voltage.,. ,, greater than the allowable value of X LGPl UH + D and, reaches the UQ level after a time less than tl, and voltage less than the allowable Ujj - D and, in a time greater than Cj. The pulse duration of the multivibrator 3 is set equal to the time Tj, a. MyjtbTH-. the vibrator 4 is equal to tj. The explored sinusoidal voltage is fed to the inputs of the comparator devices 1 and 2. At the transition of the sinusoidal voltage DX, the zero value at the output of the comparator 1 device appears, which sets the RS-triggers 7 and 8 to zero and triggers multivibrators 3 and 4, which quash the operation of the electronic keys 5 and 6. At the moment when the voltage under study UX reaches the value Ugr, it triggers the comparison device 2. There may be the following cases. If the test voltage is greater than the allowable value Ujj + D U, then the pulse at the output of the comparator 2 device sets the RS flip-flop 7 to the state 1, the transponder is illuminated More than the norm. If the voltage is less than the allowable C1-D1to impulse from the comparator 2 device arrives after the time tj T2-Key 6 is open and the RS-trigger 8 is set to state 1, the Less-than-normal transponder lights up. If the signal under study does not go beyond the permissible Ujjt D U, then both electronic keys are closed and the triggers remain in zero states. The Norm signal is output to the control system through the AND 9 element. To quantify the signal under investigation, it is necessary to measure the time interval between the output pulses of the comparison circuits 1 and 2. The amplitudes of the signal under study are determined from the expression Xtt1 bin U) tjj Such a control device has a high speed (parameter monitoring time is less than a quarter of the input signal period), except in addition, it allows the quantification of the measured voltage. Formula invented and. A device for control of alternating voltages, containing two comparison devices, whose inputs are interconnected and serve as the input of a monitoring device, their other inputs serve as inputs of reference voltages, and two keys, whose inputs are connected to the output of one comparison device, differ from that that, in order to increase the speed of the device, two multivibrators, two triggers and an AND element are introduced into it, and the output of another comparison device is connected via multivibrators to the control inputs of the keys and directly with zero inputs of triggers, outputs of keys are connected to single inputs of triggers, respectively, zero outputs of triggers are connected to inputs of element I. Sources of information taken into account during the examination 1. USSR author's certificate No. 397862, cl. G 01 R 31/28, 07.09.70. 2. USSR author's certificate number 352168, cl. G 01 R 19/04, 10/13/69. Less Norn eight longer than normal