Found in a Raytheon transistor manual from the 1950s, this circuit uses one of the first commercially available transistors, the CK722. The circuit is for using a small speaker as a microphone.
This circuit uses an MW radio tuned to around 540 kHz to detect atmospheric signals, for example, from...
This circuit is intended to maintain constant current in a heating element. This element must have...
The LMV321 is a low voltage operational amplifier from ON Semiconductor. The following diagram,...