Light Dimmer with Infrared remote control



This is a light dimmer for incandescent light bulbs controlled by any Sony SIRC compatible remote controller. This circuit is an original idea of Ivica Novakovic [1] and more information can be found on his website.

Its working principle is based on phase control [2]were a triac is fired a short time after each half-cycle of the AC waveform. By carefully calculating these delays it's possible to adjust the intensity of the light bulb in constant steps [3].


Design and Implementation

The original circuit by Ivica Novakovic has everything necessary to do its job. All that remains to be done is to describe what features are included in my version of the software:



The schematic is similar to the original and contains an extra led to blink every time a valid command is received.




The PCB is a lot bigger than the original one because I'm using through-hole components, PCB connectors with screws and placed most components horizontally.



The software allows the selection of 10 different levels of intensity, selectable using keys 1..0, PR+ and PR- and VOL+ and VOL-. The Mute key saves the currently selected intensity as the power on preset. The Power key toggles the power on the light bulb and saves the preset value to the current selected intensity on power off.

The power state is remembered across utility power losses so that the circuit can be used with an external switch that cuts power and still remember the last saved light intensity.



Warning: this circuit is connected directly to 230V and it might kill you if you are not careful. Both hardware and software assume the utility power is 230V/50Hz.

Here's a picture of the board, ready to work.

And finally a demonstration video.





  1. Ivica Novakovic website
  2. Phase control (wikipedia)
  3. Phase control (epanorama)



Published on Sunday 2013/01/06, last modified on Monday 2015/12/28