Found in a 90s Popular Electronics, this circuit checks if a remote-control transmitter is emitting signals. The sensor is a general-purpose type found in many electronic devices.
This circuit generates a high negative voltage responsible to produce ions in a tip electrode. The circuit...
This circuit is very useful to instantly reveal the lack of power in the local network. There are...
This circuit was found in a 1980s Intersil documentation. The integrated circuit used is not...