This circuit was found in a 1966 General Electric documentation. It makes use of direct contact water sensors and therefore requires an isolation or low voltage relay drive transformer.
Found in Popular Electronics from the 90s, this circuit is intended for a radar emitting pistol. The...
This circuit can generate signals up to 5 MHz according the power supply voltage. Frequency is...
This transmitter emits a modulated signal at a frequency given by the first transistor in the...