Features:

– Ground referenced tachometer input interfaces directly with variable reluctance magnetic pickups
– Op amp/comparator has floating transistor output
– 50 mA sink or source to operate relays, solenoids, metres, or LEDs
– Frequency doubling for low ripple
– Tachometer has built-in hysteresis with either differential input or ground referenced input
– Built-in zener on LM2917
– ±0.3% linearity typical
– Ground referenced tachometer is fully protected from damage due to swings above VCC and below ground

Applications:

– Over/under speed sensing
– Frequency to voltage conversion (tachometer)
– Speedometers
– Breaker point dwell meters
– Hand-held tachometer
– Speed governors
– Cruise control
– Automotive door lock control
– Clutch control
– Horn control
– Touch or sound switches