This oscillator produces a modulated signal using a unijunction transistor. We found it in an American documentation from 1965. The circuit modulates in frequency the generated signal.
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...
The gain for this circuit is given by the ratio between R2 and R1. The circuit is suggested by...
Only for reference this is a circuito f a commercial receiver of the year 1958. The circuit uses...