This relay shield circuit for old computers was found in January 1983 Radio Electronics magazine. The relays are sensitive types with currents up to 200 mA.
Written in an article in Radio Electronics magazine in April 1987, this circuit triggers an alarm...
This is the receiver circuit for the previous transmitter. The circuit has a programming key to...
This is an example of a temperature sensor shield using the Texas Instruments TMP390 obtained from...