# troubleshooting my design?



## AussieApprentice (Aug 16, 2008)

Spat72 said:


> Here is my roundabout thoughts on this issue. I don’t know for sure but it is my understanding that modern dimmers are a solid state design. I don’t know where to find internal schematics or any thing that will tell me of a typical modern dimmers design. I have heard that the dial position determines a clock speed in the circuitry and the clock controls an on/off time interval. The longer the off time the lower the light output of a bulb. The high speed flicker of a standard CFL bulb used behind a dimmer seems to support that theory. So my thought is maybe something to do with the low spike voltage by photo control in comparison to the high spike voltage of a standard mechanical switch is the issue. I just don’t know but I am thinking somehow the photo control is causing a lockup in a transistor in the dimmer every once in a while.
> 
> I hope someone here understood that!!
> 
> Thanks


The basic circuit idea sounds OK. 

The output from the photo control should be full voltage and a full wave form so it should not affect the dimmer. Does the photo control have a solid state relay or a conventional coil relay?

What type of lights are you running from the dimmer and is the dimmer appropriate for the type(leading/trailing edge)?


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## Spat72 (Oct 20, 2008)

AussieApprentice said:


> The basic circuit idea sounds OK.
> 
> The output from the photo control should be full voltage and a full wave form so it should not affect the dimmer. Does the photo control have a solid state relay or a conventional coil relay?
> 
> What type of lights are you running from the dimmer and is the dimmer appropriate for the type(leading/trailing edge)?


Thanks for your help. I would assume the photo control is solid state as well. It is one of those tiny 1" X 1" block body with a 3/8" dia. lens shaft.

I bought them both at Lowe's so I am thinking maybe it's the "cheap" quality parts are not good enough for such an unintended application. I just hate to go spend $50+ on a better dimmer and still have the problem.

I currently have a type A LED bulb in a conventional type fixture on the porch. But this problem existed for the first couple months with a standard incandescent bulb as well. The other light over the sink is a halogen puck light with 120V bulb (no transformer). I currently have the dimmer at about 50% on and it is less problematic. I would rather have it at about 30% but the problem is more common with a lower setting.

The dimmer is a Lutron - GLPB BO 8721. Not sure of the leading/trailing edge designation, I assume that is the signal cut off points. Heck I wish I knew more about the inner workings of most devices Got a source for that?

Really would like it to work properly. Darn thing was off last night. Thumbing for proper key with hand full of groceries in the dark is a pain!

Thanks


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## machasman (Mar 10, 2009)

sounds like your pulling some pretty good amperage through that dimmer. Its my beleif that any type residental dimmer will burn in espesiall the dimmer you go.

gut feeling


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## Randy L (Jun 11, 2008)

Most of those NPT style photocells, that I am familiar with, are rated at 600 watts. The two fixtures he has shouldn't even equal half that...he'd need two 150 watt bulbs for that.

Just for fun, have you taken a multimeter and measured the voltage at the fixture when the system is not working?

You also state the problem is more frequent when you have the dimmer set at 30%. The problems happens less frequently at 50%. Try this; set the dimmer at 80%-full and see if the problem still happens. Let us know what you find.


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## luby104 (Mar 28, 2009)

Neat idea spat. You've probably already solved the problem by now.
But I would think that a small 110VAC relay after the photo control wired to pull in the
full 110 volts at the dimmer instead of coming through the photo control might be worth a try.


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