DEVICE FOR CONTACTLESS MEASUREMENT OF MOMENTARY VALUES OF PULSES OF BREAK CURRENT IN SWITCHING SECTIONS OF COMMUTATOR MACHINE Russian patent published in 1996 - IPC

FIELD: electrical engineering. SUBSTANCE: device belongs to electric measurement technology and may be used for measurement of parameters while checking switching in commutator electric machines. Induction pickup 1 of break type is installed by edge of brush between riser and brush close to it. Signals across pickup 1 are measured. Signal proportional to derivative of total measured current is fed through amplifier 2 with controlled gain factor to input of first analog key element 3 and to first input of comparator 14. Reference voltage is constantly supplied to second input of comparator 14 from source 27 of reference voltage. At same time instrument converter 9 forms signals proportional to distance between break pickup 1 and commutator bars across output. Total signal from output of instrument converter 9 is simultaneously fed through precision rectifier 10 to input of amplitude detector 11 and to input of discriminator 17 and directly to input of pulse selector 19. Correction of gain factor of amplifier 2 is proportional to change of value of air gap between each commutator bar and break pickup 1. For referencing of value of break current to ordinal number of section or commutator bar signal from output of discriminator 17 goes to input of counter 21. Circuit is set into initial position with the aid of key element 26. EFFECT: increased authenticity of measurement results. 3 dwg