Development of Airblast Circuit Breaker: The development of Airblast circuit breakers has taken place in three stages shown schematically in Fig. (15.19): Momentarily pressurized Airblast breakers with isomaker in the…
Circuit Breaker Rating: The ratings of a circuit breaker refer to the characteristic values that define the working conditions for which the circuit breaker is designed and built. Circuit breakers…
Coincidence Type Phase Comparator: The basic concept of phase comparison is simpler in that it is possible to deal with signals of equal strength whose coincidence (or noncoinecidence) is readily…
Phase Comparator Circuit: Phase Comparator Circuit technique is the most widely used for all practical directional, distance, differential and carrier relays. If the two input signals are S1 and S2…
Static Amplitude Comparator: If the two input signals are S1 and S2 the amplitude comparator gives positive (yes) output only if S2/S1 ≤ K (Fig. (11.1)), S1 is the operating quantity…
Zero Crossing Detector Circuit: Zero Crossing Detector Circuit basically involves the sine to square wave conversion by a level detector circuit followed by a pulse circuit, which consists of one…
Sampling Circuits: Sampling Circuits is one which allows a comparison of instantaneous values derived at different instants of time, thereby dispensing with the need to phase shift and mix signals…
Potential Transformer Tests: The three Potential Transformer Tests are namely, Polarity check, Ratio check and Phasing check. Polarity check: Polarity check in Potential Transformer Tests is performed in the same…