Amplitude comparator compares the amplitudes of two (or more) input quantities. The phase angle between the quantities under comparison (inputs) is not recognized or noticed by the amplitude comparator. If the two input signals are S1 and S2 (say S1 the operating and S2 restraining), the amplitude comparator gives positive output only if – S2/S1 < K. The function is [...]
Phase comparison technique is the most widely used technique for all practical directional, distance, differential and carrier relays. In a phase comparator, the operation of the relay takes place when the phase relation between two inputs S1 and S2 varies within certain specified limits. Both inputs must exist for an output to occur; ideally, operation is independent of their amplitudes, [...]
Distance relays can be either single phase or polyphase using multi-input comparators. Such multi-input comparators may be instantaneous or integrating type and compare either phase or amplitude or both. The characteristics of conventional two-input comparators are in the forms of straight lines, circles or sectors of circle on complex plane. Multi-input comparators may have elliptical, conical or quadrilateral characteristics on [...]
Learn about the comparison between filament lamps and fluorescent lamps. Comparison # Filament Lamp: 1. Simple, reliable and cheap. 2. Average life 1000 hrs. 3. Reddish Light. 4. Life is not affected by frequent switching. 5. No stroboscopic effect. 6. Voltage variations, which vary with the wattage, affect the temperature, efficiency and also the life. 7. Brightness is very high [...]
Learn about the comparison between conservancy and water-carriage systems of sanitation. Comparison # Conservancy System of Sanitation: 1. Conservancy system is very cheap in initial cost. 2. Due to foul smell from the latrines, they are to be constructed away from the living room, so building cannot be constructed as compact units. 3. The aesthetic appearance of the city cannot [...]