This circuit is from a 1975 Miniwatts magazine, therefore using Philips components from that time, now difficult to find. The circuit directly controls a heating element via a Triac.
This Wien bridge oscillator was found in an Analog Devices documentation from the 90's. The...
This circuit is from American documentation from 1970. It can be designed with a BC558 and for the...
Found in an EEE from 1970, this circuit supplies a voltage of 12 V DC x 10 mA current from the...