Geiger counter with high voltage source (CB22333E)

This circuit includes a high voltage inverter to power a Geiger tube. We found it in an American documentation from the 60s.

RS232 temperature interface (CB21278E)
Found in an Electronic Design from the 90's, this circuit uses common components. The circuit is...
Locked Light Relay (CB3868E)
When the sensor receives light, the relay closes its contacts and remains so even after the light...
90V Pulser (CB8838E)
This circuit produces pulses of 90 V at intervals that can reach 5 minutes. The circuit is from a...