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🔌General Home Automation => Automating Your House => Troubleshooting Automation Problems => Topic started by: GStuttman on March 05, 2012, 10:18:33 PM

Title: Problem with 12 volt lights
Post by: GStuttman on March 05, 2012, 10:18:33 PM
I moved and had an old Lamp Module LM465 that I wanted to use with 12 volt high intensity lights that each have their own dimmer. I use AHP and various other controllers. I plugged the 2 lamps into a 3 way adapter that was plugged into the LM465 and the lights did not work. I had a night light that I was going to use for trouble shooting and when I plugged it into the 3 way adapter all the lamps worked. Does anyone know why the lamps in the LM465 work with the night light plugged in but does not work if it is not plugged in?
Title: Re: Problem with 12 volt lights
Post by: Brian H on March 06, 2012, 05:59:35 AM
The LM465 is not designed to work with low voltage light power supplies and didn't like the load.
Adding the night light bulb calmed down the LM465 enough to work.
Unless the low voltage lights power supply is designed for a dimmer. Both the low voltage supply and the LM465 can be damaged by continued use.

The lights have their own dimmer also? Trying to use a LM465 on lights with built in dimmers is also a very bad idea. Again asking for damage to to the lights power supply or the LM465.

Best to use an  appliance module and not to dim them.

Title: Re: Problem with 12 volt lights
Post by: pomonabill221 on March 06, 2012, 02:05:02 PM
   It also sounds like the light's dimmers (not the lm465) may have a switching power supply in them, and SMPS's don't normally like to be fed phase angle AC (triac dimmer that the lm465 is).
   The night light is a purely resistive load and maintains the phase angle control from the lm465 allowing the triac to trigger, where the SMPS is a non linear load.  The input to SMPS's are normally a half or full wave bridge rectifier, and do affect a triac's triggering angle.
   I have been using this type of lighting on a track light, with one of the lights a 25watt incandescent for just the  reason that you have done with the night light.
   I have not had any problems dimming these lights, but each SMPS is designed a little different so not all will work.
   Use your night light along with the high intensity lights that you have and give it a try.
  Monitor the lm465's temp (by feeling it) and if it gets hot, try something else.
  You may damage the triac (usually goes open), but I would guess that the nightlight should keep that from happening.... YMMV and I cannot guarantee that it will work for you.
Title: Re: Problem with 12 volt lights
Post by: cjhallx on March 06, 2012, 03:23:26 PM
Another reason may be that using the additional light adds enough current draw.. Some of the switches will not work unless their is a minimal amount of load  albeit how small.