This power supply is based on the 723 integrated circuit, which is no longer very common today. The transistor must have a heatsink and the bridge can be formed by diodes 1N4002 or equivalent.
This oscillator was found in a 1967 General Electric documentation. The UJT is P-channel, an unusual...
Found in an Elektor from the 90s, this circuit triggers a Sonalert-type buzzer when the sensor is...
This precision circuit can provide timings from 0.2 milliseconds to 3 minutes accurately. The...