This filter circuit for active frequency divider applications was published in the December 1957 Radio Electronics magazine. The supply voltage is indicated.
This circuit, from a 1988 documentation, consists of an automatic temperature control using an NTC...
This power supply, found in an Argentine publication from the 1970s, uses a wire potentiometer of 25 W or more...
With this type of circuit, it is possible to obtain high input impedances and, at the same time,...