Patent RU-2057349-C1 (RU)
Inventor: SAMOKISH VYACHESLAV V
IPC: G01R21/133
Filed: 1992-10-20
Granted: 1996-03-27
Abstract: FIELD: electric measuring technology. SUBSTANCE: power-to-frequency converter (first variant) includes input current and voltage converters which inputs are connected to proper input wires and which outputs are linked to inputs of first and second modulus formers, multiplier, which first and second inputs are connected correspondingly to first outputs of first and second modulus formers and which output is linked to first input of first controlled inverter which output is linked to input of integrator, first and second comparators which out inputs are connected to inputs of first logic OR-ELSE gate, low-frequency filter, second controlled inverter, second and third logic OR-ELSE gate. First comparator is manufactured hysteretic one and its output is frequency output of device. Second outputs of first and second modulus formers are connected correspondingly to first and second inputs of second logic OR-ELSE gate which output is linked to first input of third logic OR-ELSE gate and to second input of second controlled inverter which first input is connected to output of multiplier and which output is connected to input of low-frequency filter which output is analog output of converter and is linked to input of second comparator which output forms sign output of converter. Output of third logic OR-ELSE gate is connected to second input of first controlled inverter, output of integrator is linked to input of first comparator. Output of first logic OR-ELSE gate is connected to second input of third logic OR-ELSE gate. In compliance with second variant power-to-frequency converter has input current and voltage converters which inputs are connected to proper input wires and which outputs are linked to inputs of first and second modulus formers, multiplier which first and second inputs are linked correspondingly to first and second modulus formers, first inverter, integrator, first and second comparators which outputs are linked to inputs of first logic OR-ELSE gate, low-frequency filter, second inverter, second and third logic OR-ELSE gate, first, second and third exponential elements and NOT circuit. First comparator is manufactured hysteretic one and its output is frequency output of converter. Second outputs of first and second modulus formers are connected correspondingly to inputs of second logic OR-ELSE gate which output is connected to first input of third logic OR-ELSE gate and to first input of third exponential element which second input is linked to first output of multiplier and to second inputs of first and second exponential elements. Output of first exponential element is connected through first inverter to input of integrator and to output of second exponential element. Output of third exponential element is linked through second inverter to second output of multiplier and to input of low-frequency filter which output is connected to input of second comparator and is analog output of converter. Output of second comparator forms sign output of converter. Output of integrator is connected to input of first comparator. Output of first logic OR-ELSE gate is connected to second input of third logic OR-ELSE gate which output is connected to first input of first exponential element and through NOT circuit - to first input of second exponential element. EFFECT: power conversion is conducted with relatively small error with any direction of average power in measured circuit. 7 cl, 6 dwg