Calibrated-tachometer


Posted on Jul 3, 2012

Here is a simple tachometer circuit for use with a hand-held DVM or portable chart recorder. A novel feature is that the source frequency pulse/rev rate can be directly set on a ten-turn potentiometer to provide a convenient calibration of one V per 1000 rev/min. This is particularly useful when measuring a shaft or engine speed by sensing gear teeth.


Calibrated-tachometer
Click here to download the full size of the above Circuit.

The circuit uses an LM2917 IC which is specifically designed for tachometer applications. The tenturn potentiometer, which provides the pulse/rev setting, is suitably configured in the output amplifier feedback path. The pulse/rev range is 100 to 1100, so the potentiometer dial mechanism should be set to start at 100 to provide direct calibration. The IC"s internal 7.5-V zener provides stable operation from a 9-V battery. The tachometer accepts an input signal between 50 mv and 20 V rms and has an upper speed limit of 6000 rev/min with the component values shown.





Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

MOSFET Headphones
Electronic Siren based NE555
Analog To Digital Converter
flasher and lighting control circuits
IR Widget Consumer infrared remote control capture and visualization
Keyer circuit
Voltage-Doubler Circuit



Top