Non Inverting Amplifier (CB6437E)

This non-inverting AC amplifier was found on a Popular Electronics. The setting applies to any operational amplifier.

Telephone Tone Generator (CB13935E)
This double tone generator uses a specific integrated circuit, having been found in a 1977 CMOS...
Simple Transistor Test (CB17139E)
This circuit is used to test PNP or NPN transistors giving the status indication through LEDs. The...
Dimmer (CB5270E)
This dimmer for incandescent lamps was obtained from an American 1990s documentation. The circuit...