This circuit is from an American 80's documentation. The integrated circuit is from the time and the sensor consists of a smoke chamber measuring its transparency change.
Published in 1988 in Hands On Electronics, this circuit converts the 12 V of a battery into 120 V AC...
The current accross the LED as function of the resistor value is given by the formulas. The...
This circuit was found in an old 1980s valve documentation. The circuit can directly replace a...