Found in a 1970 American publication, this circuit uses transistors of the time. These transistors may be replaced by current equivalents. The factor Q is greater than 3 000.
This circuit uses an operational amplifier to simulate an inductor. The circuit is from old...
This timer counts down the times until, at the end, it activates a relay. The programming time is...
Although it is a common configuration today, this circuit was taken from an old publication. The...