Process timer (CB21865E)

We found this timer for times of a few minutes in a 1974 Ferranti transistor manual. The relay is 37 mA sensitive type.

Logic Gate with LED Indicator (CB14628E)
This circuit is from a technical documentation from Texas Instruments from 1978. In it we have the...
Operational Multiplier and Divider (CB13812E)
We found this circuit in a publication with experiments with operational amplifiers from 1973. The...
FM modulator with varicap (CB6913E)
Using a varactor or varicap, this 1969 Electronics World circuit has a modulation range from 75...