Found in a 90s Popular Electronics, it serves both TTL and CMOS logic. The injector can provide 10 kHz or 100 Hz signals. The circuit drives a transducer and two LEDs.
This precision circuit can be implemented with other operational ones. We found it in a...
The circuit shown in the figure causes a piezoelectric transducer to emit interval beeps. The 100...
This range corresponds to the lowest TV channels, 2 and 3 specifically in VHF. The circuit is from...