This optically coupled circuit was found in the February 1968 Radio Electronics magazine. The circuit uses an LDR in modulation. Transistors are types of the time.
This circuit is based entirely on TTL gates. The circuit must be powered by a voltage of 5...
This transmitter operates in the FM band emitting beeps that can be picked up on a common radio at...
This circuit was found in a 90s European documentation. The circuit already includes a powerful...