Low Voltage Test (CB22158E)

This is a simple voltage tester for voltages from about 2V to about 15V with the indicated resistor and red LEDs.

NB FM audio amplifier (CB7462E)
Found in a documentation from the 90s, this circuit limits and amplifies a voice signal in the 800...
Fence Electrifier (CB12895E)
This circuit is from an Argentine publication from the 1970s but can still be assembled with...
Low voltage drop regulator (CB21216E)
This simple LDO, or low voltage drop regulator was found in an Electronic Design from the 90s. The...