Static Distance Protection Relay: Static Distance Protection Relay are characterized by having two input quantities respectively proportional to the voltage and current at a particular point in the power system,…
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…
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…
Smoothing Circuits: The rectified a.c. consists of a series of undirectional half waves of current or voltage. It is generally desirable to smooth this output. The various filters used for…
Logic Circuit in Static Relay: The concept of Logic Circuit in Static Relay can be better understood by considering the logic operations performed by the devices rather than the actual…
Unijunction Transistor in Static Relay: Unijunction Transistor in Static Relay is a three terminal device with only one pn-junction. It is made up of n-type silicon wafer having two base…