This symmetric 30 mA x 15 V power supply was found in the Ferranti transistor manual from 1974. Transistors are common types at the time.
This light effect was found in a European circuit manual from the 90s. The triacs can be of the...
This is an improved circuit from the earlier version also found in the April 1972 Radio...
This circuit uses integrated 555 and an amplification step with transistors, as we can see in the...