This circuit is intended for underwater communications. Of course, the critical point is the shielding to avoid water. The circuit is from an Electronic Hobbysts Handbook from the 90s.
This circuit has a frequency range of 30 Hz to 100 kHz with an output signal of 1 Vrms. We found...
This circuit is suggested by the Optoelectronics Sourcebook by Texas Instruments when AC signals...
This sequential relay actuation system circuit for traffic lights was found in Electronics Now...