Re: ---My wiring questions (was progress on Travelette - premature sending)

["Allan Ericson" <lowvolt@xxxxxxxxxxxx>]

Thomas-

I would agree with Howard except for one minor detail.

Measure the voltage across the rheostat when you have the light exactly how
you want it.

Then use the ohm meter function to measure the resistance of the rheostat
you are now using. As Howard said, it should tell you exactly what size
resistance to use.

Take the voltage reading and SQUARE it. Divide by resistance reading.

That number is how much wattage is being used by the rheostat. Double that
number. That's how much wattage you want on your resistor. With luck, the
number will be less than half a watt so you can buy the resistor at Radio
Shack. If it's not, post back, and I'll tell you where you can find the
right resistor.

-Allan
----- Original Message ----- 
From: "T.R.E. Jr." <T_R_E_Jr@domain.elided>
To: "IHC Digest" <IHC-Digest@domain.elided>
Sent: Sunday, June 29, 2003 11:16 AM
Subject: ---My wiring questions (was progress on Travelette - premature
sending)


> ---As for my Scout II... it was evident that it needed a nerve
> reconstruction surgery. Which BTW, now that I have installed a completely
> new system, I am considering changing out the gauge illumination from the
> original 158 bulbs to 194 bulbs. Can't wait to see how bright the gauges
> will be afterward.
>
> ---Now my question. I have installed a digital clock from a `90 model
Taurus
> (fit the original hole perfectly). I need a resistor in the
> lighting/ignition circuit but don't know what ohm rating. I have a digital
> multimeter with ohm ranges 200, 2k, 20k, 200k  and 2000k, DC Voltage
ranges
> of 2V, 20V, 200V and 450V Not knowing too much about electrical
engineering,
> I have set the lighting/ignition circuit on the clock to the rheostat
> feature on an old headlight switch. I am now able to adjust the voltage to
> the clock, and get the clock to light up clearly without drowning out the
> numbers. So what's next? use the voltmeter to complete the circuit after
the
> rheostat and take a reading. Here is where I think I need an equation to
> figure what ohm resistor I would need to install in the circuit... anyone
> have one for me? :D
>
> ---Thank you,
> -T.R.E.Jr.
> -`73 Scout II (StoneThrower)
> -`51 Farmall H (Heinz)
> -`49 IH fridge (presently unnamed and in need of a compressor)
> -`49 Plymouth Special Deluxe 4-door Sedan (Papapalooza)