This circuit is from an old Japanese publication of 1962. The circuit uses two batteries, one for the filaments of the tubes and the other one of high voltage for the plate circuits.
The purpose of this project is to monitor remote loads. The windings are made in a burnt...
This circuit allows to activate three functions in a controlled way, determined by a diode array....
This circuit is from Radio Electronics. The magazine no more exists, but the circuit can be...