Address decoder using the 74LS138 (CB20537E)

This decoder circuit 3 of 8 was found in a publication for PCs from 1992. The circuits are TTL and must be powered with 5 V.

20 minute timer with PUT (CB4254E)
This circuit was found in the ON Semiconductor's Thyristor manual of the 1980s. The high quality...
Pulse Width to Capacitance Converter (CB6100E)
Suggested by Linear Technology, this 80's circuit makes use of an operational of the time but can...
Active Cycle Detector (CB6529E)
This circuit was obtained from a Popular Electronics of the 80's. It is set to a certain pulse...