This circuit is temperature stabilized. Modern equivalent transistors can be used, and the power supply can actually be between 9 and 12 V. The circuit is from an old documentation.
Found in a 1968 US publication, this circuit is designed to measure very weak signals. The...
The sensor can be made using two bare wire or two screen with a piece of tisse between them. One...
This circuit serves as a binary demonstrator using 3 LEDs. The circuit can be scaled up for a...