This circuit was found in a 90s Electronic Design. The circuit is for TTL technology and can function as a shield for microcontrollers.
This is a possible circuit for the receiver of the previous circuit. Other circuits can be found...
This small transmitter with 2 transistors can reach several hundred meters using a 30 to 70 cm...
Using the 4001 integrated circuit, this latching relay can employ any general-purpose transistor. The...