Using digital signal processing techniques in light controllers

In some European countries, the electric power stations sends out controlling codes modulated onto the net frequency in order to synchronize all the public timers. These features are detected as modulated noise by the light controllers in the house. A digital filtering technique that does not require a dedicated digital signal processor is presented. A small, low-cost, 8-b processor is used to handle the remote-control commands and at the same time digitally process the signals fed to the triac-component in order to remove blinking effects and direct-current displacements. The noise cancelling method is described, and general results and some suggestions for improvements of the method are given