Smart Light Switch Replacement

Dammo

I swapped a regular light switch for a smart switch. I put the capacitor that came with the smart switch into the ceiling rose and it eliminated the flicker in the bulbs. All fine but it turns out that the light is on a loop with 3 other rooms. Now when the lights are switched on in one of these rooms, there is the briefest of flashes of the light with the smart switch.

Any suggestions on how to deal with this?

Bluefoam

*deleted

10-10-20

Did you just need the module as you had no neutral at the switch?

Is the module a dimmer type or just a binary switch?

Dammo

Thanks for the reply. No neutral at switch. Not sure about the module (capacitor?). Came with the switch but there was no mention of dimmer on listing.

10-10-20

You might be stuck with the flash with that particular model. Does the same happen if the light is in the min brightness position as opposed to being "off"?

Electrically speaking, as these switches don't have a neutral they have to approximate 0v as a reference voltage so they do this by creating it from the existing AC wave. The problem happens when that incoming 230v @ 50Hz is disturbed by an external factor - such as a light on the same circuit being switched, and the AC waveform is then distorted by the capacitor/bypass circuit. This causes the reference 0v in the switching circuit to go "high" for a moment and you get a flash as the voltage spikes across the MOSFET's input.

Basically, some models of switch could do this more than others, and ones which put a light into a brightness minimum position instead of fully off may suffer more. You might try swap out either the bypass/capacitor with another, or the switch, etc.

Also check online - some of the UK electrical forums are handy for these issues.

Dammo

Cheers, appreciate the input 👍