Found in a 1968 EEE, this circuit accepts frequencies from 1 to 1000 Hz and control voltages from 0.1 to 15 V. The operational amplifier is from the era and can be replaced by modern equivalents.
This circuit has a logarithmic response as a function of the light falling on the sensor. The...
This circuit was found in documentation from the 70s. The transistors are from that time, but the...
The idea is simple: using a flashlight to cut your TV commercials triggers a relay that turns off...