Leak Detector (CB22456E)

We found this circuit in a Popular Electronics from 1992. The transistor is general purpose, assuming equivalent.

Diode Noise Generator (CB4127E)
This noise generator uses the thermal noise of a common diode junction. The circuit is from an...
Optical Isolator Power Switch (CB12413E)
This solid-state relay (SSR) or shield was found in a 1995 Electronics Now. The transistor can be...
Capacitive Loads Driver Circuit MC34001 (CB15275E)
Other operational amplifiers from the same family such as MC34002, MC35001, MC34004 and MC35004 can...