This circuit was found in a 1968 Motorola documentation. The circuit can be implemented with virtually any photo transistor and general-purpose transistor.
This power source was found in a 1968 Electronics World. The transistors are from that time. The...
We found this circuit in an American documentation from the 60s. The circuit can be made with...
This TTL dice is from an old publication from 1978, but it can still be assembled, as the...