Relay driver (CB20549E)

Found a documentation on PCs from 1996, this circuit can be used as a shield. The relay is rated at 100 mA of coil current.

Modulated light receiver (CB7846E)
This circuit is indicated to function as a receiver of the previous circuit. The circuit is from...
1 Hz Time Base 2 (CB24205E)
We found this time base circuit in a timer project from the August 1972 Radio Electronics...
1 kHz Low Pass Filter (CB24386E)
This basic op amp filter configuration was found in July 1975 Radio Electronics magazine. The...