This circuit was found in a 1966 EEE. The circuit uses transistors from the time but can be made with modern equivalents. The operating frequency ranges from 0.1 to 1 kHz.
We found this anti-theft circuit in a 90's English publication. The circuit uses common components...
This circuit transmits signals with good power in the range of 1 to 10 MHz using only integrated...
The circuit below is a two-band timer that directly triggers a sensitive relay (less than 20 mA...