Found in a 1969 EEE, this circuit is based on an operational amplifier of the time and on old type MOSFETs. The components support modern equivalents.
Published in an old Popular Electronics, this circuit makes use of components that are still...
Suggested for the control of photographic enlargers, this 1967 General Electric circuit uses still...
Found in old documentation, this oscillator operates with high voltage. The diode must be of the...