3-Stage Level Indicator (CB24561E)

Using the Texas Instruments SN75489P this circuit was found in June 1978 Radio Electronics magazine. The power supply is from 10 to 18 V.

Dwell Meter (CB4961E)
This circuit is from the time when cars used contact breakers. This 80's version measures the dwell...
Tolerance Indicator For Capacitors (CB4650E)
The basic idea of this circuit is to indicate the tolerance of a capacitor by reference to a...
Multitester (CB3834E)
This simple multitester tests continuity, semiconductors, leaks, and other common component...