Triac Dimmer - Do I Require An On/Off Relay

Hardware
1

I am considering using this triac dimmer to control some LED dimmable grow lights.

I currently have a relay that switches the dimmable LED lights on and off (does not control the dimming).

Using the triac dimmer, if I pass a zero PWM value to the dimmable lights, will this zero PWM value mean the dimmable lights are off, and I can dispense with the on/off relay?

I have read several articles on the issue, but there appears to be no concrete answer.

2

You need to read the datasheet for your light to understand how to power or control it. It’s impossible to answer the question “will these two devices work together” while only knowing about one of the two devices.

It’s unlikely that this is what you need if you’re using a commercial LED grow light. Those lights often require a 0 - 10 VDC or 10 VDC PWM signal.

3

NEVER NEVER NEVER use triac dimmers on any sensitive electronics! If you try “dimming” your LED power supply, you will very likely damage it.

4

Dimming control via firing angle method. This is stated in the spec of your ‘triac dimmer’.

This means that the LED will have instantaneous power applied every half cycle of mains. This causes all sorts of electromagnetic problems and reduces the life of the LED. You need to state the make of your LED bulbs.