Found in a 1980s American documentation, this circuit uses programmable unijunction transistors of the time. The time interval obtained depends on the capacitors that can be changed.
This circuit is from 1987 when there were only analog TVs and stereo sound was still a novelty for this...
This circuit was obtained in a 90s documentation. However, it can be developed with modern...
This circuit uses a FET to drive an LED with constante currente. The current up to 20 mA can be...