This circuit was found in Motorola documentation from 1966. The lamps are according to power and current according to the components used which are uncommon today.
This 1969 Philips documentation circuit makes it possible to control an engine through the sound...
The absence of a pulse in the pulse train applied to the input of this circuit causes a high level...
Found in a 1970's Radio Electronics, this circuit uses a triac to switch loads on the AC network. This...