Using an LDR as a sensor and an operational amplifier this circuit was found in the Encyclopedia of Electronic Circuits volume 5 from 1995. The circuit triggers an optodiac.
This circuit decodes a 1800 Hz tone used in communications. The circuit is from an American...
These two circuits were found in Radio Electronics magazine from February 1960. The transistor is a power...
With the development and availability of small LCD screens for automotive use, especially in...