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 is from an Argentine publication from 1973. It generates a 100 kHz signal from a...
This filter was found in a 1975 American technical publication. The filter can be of any type and...
This circuit was found in a 90s American documentation. The circuit uses still common components...