Description

The AT Series tachometers are rugged, transistorized instruments with solid-state circuitry for indication of engine RPM. They are equipped with a bracketfor mounting into a standard 3- 3/8 in. (86 mm) dash mounting hole. A full 270° sweep of the pointer gives an accurate indication on a large easy–to–readscale and the dial can be illuminated for night reading. The ATH Series models are also equipped with hourmeter to record the elapsed running time of an engine.

Models available for Alternator, Magnetic Sensor or Ignition signal. These instruments are designed to function from pulses generated by an alternator with 4, 8, 12, 14, or 16 poles on the rotor. The pulses can also be obtained from the ring gear of an engine by means of an electromagnetic sensor(magnetic pickup). Murphy’s magnetic sensor driven models are designed to function with flywheels having anywhere from 50 to 304 teeth. Ignition signal model available for 4, 6 or 8 cylinder, spark-ignited engines. All models are for negative ground, positive ground or isolated electrical systems and are protected against reverse polarity hookup.

All models are powered by a 11-28 VDC battery and are reverse polarity protected.

Series Models

ATS Series Magnetic Sensor Signal Tach
50-304 flywheel teeth* 11-28 VDC, 2733 Hz to 13.62 kHz @ 4000 RPM
ATHS Series Magnetic Sensor Signal Tachometer/Hourmeter
50-304 flywheel teeth* 11-28 VDC, 2733 Hz to 13.62 kHz @ 4000 RPM
ATA Series Alternator Signal Tachometer
3-32 pulses* 12 VDC, 137 to 1330 Hz @ 4000 RPM
ATHA Series Alternator Signal Tachometer/Hourmeter
3-32 pulses* 12 VDC, 137 to 1330 Hz @ 4000 RPM or 193 to 1815 Hz @ 4000 RPM
ATHI Series Ignition Signal Tachometer/Hourmeter
4, 6 or 8 cylinder engines @ 4000 RPM

Applications

These tachometers are specially designed for use on truck, marine, industrial, or stationary engines.