This circuit consists of an inverter powered by only 4.5 V. The circuit is from a 1967 Mullard documentation. No information was provided on the transformer winding. Capacitors can be 1.5 nF x 3 kV.
This circuit was found in a 1965 General Electric manual. What it does is give a warning if you...
The sensor in this circuit is a BA315 diode. Other diodes can be experimented, but this is one...
This circuit turns on your car's backlight when a vehicle coming from behind gets too close to it...