Critical components of this project are the Geiger tube and the 300V battery. The battery can be replaced by a small inverter, as the circuit current is few microamps. The circuit is from an old documentation. Transistors are general purpose types.
This circuit is from a cookbook to timers. The circuit is triggered by an external signal and,...
This is a general purpose pramplifier launched in Brazil by Philips in the years 70. The BC549 is...
This circuit turns on your car's backlight when a vehicle coming from behind gets too close to it...