Suggested for the control of photographic enlargers, this 1967 General Electric circuit uses still common components. The circuit directly controls a lamp for exposing negatives.
This circuit was suggested by Motorola in a 1980s publication. It is based on a PUT that is not a...
We found this circuit in an old documentation, using an operational of the time. The circuit...
This circuit uses a pickup coil to take the signal from a telephone line without contacts. The circuit...