Found in a 1924 documentation, this circuit is powered by 3 batteries, two of which are high voltage. The output is a high impedance headphone jack.
This circuit for automotive use was found in American documentation from the 90s. The circuit uses...
This is the name given to the 1969 Electronics World voltage inverter. It is a series converter...
We found this circuit in an 80's Electronic Design. It makes use of couplers of the time that can...