Found in a 90s Elektor, this circuit is based on a Maxim integrated circuit of the time. The circuit supplies 5 V at its output with a maximum current of 50 mA.
The basis of this circuit is a CA3130 operational amplifier. The transistor can be BC548, and the...
This circuit, found in a 73 magazine for radio amateurs, is used in radio localization. The...
This circuit is from an American magazine Popular Electronics of March 1991. The circuit produces both...