This flasher circuit consists of an astable multivibrator with the frequencies given by the capacitors. The circuit is from 1965 using light bulbs, but LEDs can be used. Power comes from 4 batteries.
This drain dip oscillator was found in an old English documentation. The JFET can be of any type...
This circuit was found in a 1977 timer cookbook. The circuit can generate signals with up to 99%...
This didactic circuit was found in an English publication of 1965. The sensor is an LDR and...