On Wed, Jul 11, 2001 at 11:47:50PM +1000, Roman Black wrote:
> chucksea@mindspring.com wrote:
> >
> > I think what he was asking was the nuts
> > and bolts of how do you do the actual wiring?
> > Does the resistor go in the socket somehow?
> > Do you have to pull the fixture out of the
> > ceiling and add a resistor inline with wirenuts,
> > black tape, etc??
>
>
> > > Hey Roman - I know this hasn't been mentioned for a while,
> > > but I was wondering:  how do you physically implement
> > > the 5% resistors?
> > > Thanks.
>
> OK, point taken. I can't really help you here.
> The resistor will dissipate maybe 3w with a 60w
> bulb. That is a HOT resistor. You need at least
> a 10w resistor.
> As Jinx said, expect maybe 40'C temp rise
> (60+ degrees at the resistor) so that is very "ouch".
>
> My experience was as an apprentice where the
> oldtimers showed me some high outdoor light fittings
> that had 5% drop resistors, so they didn't have
> to change bulbs. The bulbs last for many years.
>
> I have used this with excellent result in a 100w
> incubator, using 7% volts drop on the resistors, and
> I used 2 large 20w ceramic resistors because I have
> heaps of that stuff in my junkbox. :o)
> The incubator has done thousands of on/off cycles over
> months, still the original 100w bulb.

Roman, let's start here. How did you wire the incubator? Where did you wire
the resistors relative to the light socket?

There are two major problems in wiring the resistor, high voltage and heat.
Of course this is the same two problems as wiring a light fixture, but with the
light fixture the source of heat is out in free space.

Ideally the resistor should be an a grounded, thermally coupled metal box
that's mounted in free space. It may be possible to get away with a deep
metal box at the light socket. Mount the resistor at the back of the box on
the side away from the stud. The box would then act as a heat sink for the
resistor. Note that IANAElectrician!

Frankly the thought of a radiated heat source mounted in wall is quite a scary
one.

BAJ

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