E)
This soft start dimmer was found in a Motorola documentation from 1968. However, it can be implemented with modern equivalent components like the 2N2646 for the Unijunction.
The circuit presented is based on a mechanical tuning fork. The circuit is suggested by National...
This source, from a 1982 documentation, uses a triac to control the power and voltage applied to...
This circuit was found in a 1990 Electronics World magazine. The circuit can be mounted today by...