We found this circuit with transistors in a Philips documentation from 1968. The double transistor can be replaced by discrete married types. The power supply is symmetrical.
Found in an Electronic Design from the 90's, this circuit uses common components. The circuit is...
When the sensor receives light, the relay closes its contacts and remains so even after the light...
This circuit produces pulses of 90 V at intervals that can reach 5 minutes. The circuit is from a...