This circuit can be used to obtain a zener voltage from a common zener of another value, adjusting in a multimeter. The circuit is from an American documentation of the 1970s.
Only for reference this is a circuito f a commercial receiver of the year 1958. The circuit uses...
This modulator for analog video signals was found in a 1980s Motorola documentation. The circuit...
With a 1 500 uFcapacitor this timer can reach times up to one hour. The capacitor must be of good...