Dimming a Transformer - Tilted Forum Project Discussion Community

BoltedDown · 04-25-2005, 11:25 AM

I just bought a set of 12V lights from IKEA and they came with a AC -> DC transformer.

Would it be safe and smart to use this with an X-10 lamp dimmer module?

transformer specs:

Output: 12VAC 1.67/A 20VA

If they transformer cannot be used with the dimmer, what would be an alternative way of dimming the lights?

Thanks!

BoltedDown · 04-27-2005, 05:41 AM

No dice?

Ok, how about this: What is a good website to get a mechanical dimmer that has a ~1" shank on it (so it can go through a piece of shelving)?

flat5 · 04-28-2005, 05:06 AM

The dimmer will have a messy waveform (maybe sawtooth) that the transformer will not like. (The transformer may over heat)

The device is called a rheostat, a variable resistor.
You need to know the power it has to handle.
Then call an electronics parts store and order one.

If you just want two light levels, a cute trick is to use a diode and switch across it.
By stopping the current in one direction you will half the light very efficiently.
You could use 2 amp or 5 amp diodes in parallel or some big wattage diode on a heatsink. I have no idea what power is involved.

Edit: put the diode/switch on the 12vac side of the transformer.

What is the current rating of the transformer?

04-25-2005, 11:25 AM	#1 (permalink)
BoltedDown Crazy	Dimming a Transformer I just bought a set of 12V lights from IKEA and they came with a AC -> DC transformer. Would it be safe and smart to use this with an X-10 lamp dimmer module? transformer specs: Output: 12VAC 1.67/A 20VA If they transformer cannot be used with the dimmer, what would be an alternative way of dimming the lights? Thanks! __________________ -BoltedDown

04-27-2005, 05:41 AM	#2 (permalink)
BoltedDown Crazy	No dice? Ok, how about this: What is a good website to get a mechanical dimmer that has a ~1" shank on it (so it can go through a piece of shelving)? __________________ -BoltedDown

04-28-2005, 05:06 AM	#3 (permalink)
flat5 Very Insignificant Pawn Location: Amsterdam, NL	The dimmer will have a messy waveform (maybe sawtooth) that the transformer will not like. (The transformer may over heat) The device is called a rheostat, a variable resistor. You need to know the power it has to handle. Then call an electronics parts store and order one. If you just want two light levels, a cute trick is to use a diode and switch across it. By stopping the current in one direction you will half the light very efficiently. You could use 2 amp or 5 amp diodes in parallel or some big wattage diode on a heatsink. I have no idea what power is involved. Edit: put the diode/switch on the 12vac side of the transformer. What is the current rating of the transformer? Last edited by flat5; 05-03-2005 at 02:11 AM..