The Model 1790 Tachometer Tester is used for testing and calibration of electrical
and mechanical tachometer generators and indicators. A high-quality DC motor is
coupled directly to a 1/4 inch square hole drive (AN Pad). This tachometer tester
output can be converted to a wide variety of adapters and different tachometer interfaces.
The motor drive control circuit uses SCR components and an open loop system for
an economical solution to speed adjustment. The control panel consists of a five-digit
LED display, momentary switches for start and stop, a direction switch, a display
select switch, and a ten-turn potentiometer for speed adjustment.