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 provides a signal to an amplifier from...
This filter was obtained from the Texas Instruments Linear Circuits Applications. It makes use of...
We found this circuit in a 1997 documentation. It can be used in any common 12 V source and has...