12v adapter for lights

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Its both, the regulator chip monitors both the 12V and 5 volt output. They can be easily modified to monitor just one voltage or to change the output voltage somewhat. By changing the value of a resistor you can "fool" the regulator into "thinking" its putting out more or less voltage than it really is thereby increase / decrease the output voltage. Jimmie
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On Tue, 10 Mar 2009 11:28:09 -0700 (PDT), JIMMIE

Changing the load resistance should NOT change the output voltage. That's the idea of regulation. You just need a load on the bus to stabilize it.
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snipped-for-privacy@snyder.on.ca wrote in wrote:

he's not talking about LOAD resistors,but the resistive divider inside the PS that sets the output voltage. But changing the output V of one of the output voltages will also change some of the other unregulated supplies. The supplies track each other,unless they have a separate regulator circuit.
--
Jim Yanik
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On Mar 10, 9:24 pm, snipped-for-privacy@snyder.on.ca wrote:

Excuse me, where did I say anything about changing the value of a "load" resistor?
Jimmie
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On Tue, 10 Mar 2009 19:54:59 -0700 (PDT), JIMMIE

My FIRST mention of a resistor was a load resistor. I never mentioned getting inside the box at all.
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switching supplies need a minimum load to regulate properly. And PC supplies regulate off the +5 volt line.
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Jim Yanik
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So you pop a small power resistor on the +5 to regulate, and you are on your way.
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I have a stack of old PC supplies and most of them will power up and be stable with nothing plugged into them. I know the old AT supply needed a load but the newer ones must have some internal load to regulate against.
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On Tue, 10 Mar 2009 10:52:21 -0500, snipped-for-privacy@aol.com wrote:

The ATX may not need the 5 volt load but are not as reliable, on the whole.
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On Mar 9, 10:29 pm, "Stormin Mormon"

Might not be a + if you are selling your house with one installed.
Jimmie
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On Tue, 10 Mar 2009 11:49:52 -0700 (PDT), JIMMIE

They have all the certification you might ever want so what's the problem? Just do the installation so it looks like it was planned to use that power supply.
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snipped-for-privacy@snyder.on.ca wrote in

it's essentially a custom mod that is unsupported;nobody will service it.Nobody will accept responsibility for such a mod.
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Jim Yanik
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No mod to the supply - just "plug and play"
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Depending on how closely you want it regulated a well made transformer goes a long way over the typical wall wart.
Jimmie
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On Mar 8, 9:15 pm, snipped-for-privacy@manx.misty.com (Don Klipstein) wrote:

Regulation depends on the quality of the transformer. On a lot of cheap import transformers a 12 volt transformer may put out 18 volts into a light load then drop to 10 when pushed to near there rated capacity. Get a good transformer and you dont have to worry about this. Good transformers arent cheap but neither is replacing cheap ones. My 12.6 volt 10 amp Stancor transformer only varies about 1 volt from no load to full output.
Jimmie
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JIMMIE wrote:

Besides quality, there are 2 other factors:
1. Voltage variation with change of load tends to be less with larger transformers and more with smaller ones. Though my experience is that upsizing the transformer tends to make load voltage more excessive, until the transformer gets so big that open circuit voltage is only a little higher than the nominal load voltage. A 12.6V 10 amp Stancor brand one is a big as well as decent quality transformer as far as ones to find inside a home go - though maybe only mildly oversized for 60 watts worth of halogen lights, probably not especially bad for this job after all. (If voltage runs half a volt high at 5 or slightly more amps, then 60 watts worth of halogen lamps will be supplied 13.1 volts. If the lamps get that much voltage after wiring voltage drops, expect incandescent/halogen lamps rated for 12 volts even to have life expectancy reduced maybe 60%.)
2. Most wallwarts have DC output, and not only the transformer windings but also the rectifier circuit (diodes and filter capacitor) has issues of load voltage varying with load current.
- Don Klipstein ( snipped-for-privacy@misty.com)
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The origonal power supply was too small. 57 watts power supply for 60 watt load? You need a 90 watt power supply or larger. If ther is no watt rating on the replacement I would look for 8 amps or better.
Jimmie
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fredinstl wrote:

(Amazon.com product link shortened)
Remember, the track lights are 12 volts AC, not DC. Running them on DC will work, but the wiring of the lights may not be designed for DC.
Probably it's cheaper to buy another set of lights from Ikea and use the transformer from it.
You can buy a transformer at a place like "http://www.lightwavesconcept.com/product.php?productid 549&catH0&page=1".
Maybe Home Depot or Lowe's sells them as well.
In the olden days you could buy a 12.6V filament transformer for a few bucks, but no more.
Again, it's a bad idea to buy a 110VAC to 12VDC power adapter for track lights.
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wrote:

Actually the wiring will make no difference - and as long as you are switching the high voltage (ac) you don't need to warry about DC rated switches. The lamps will "like" regulated DC better than sloppy AC too.

And have the same cheap crap fail in the same manner in the same short time??? What's wrong with this picture???

It's a waste of money if it costs you more than an adequate AC transformer - but even a GOOD NEW ATX power supply of adequate capacity can be bought for under $30 - used PC/AT supplies are a dime a dozen.
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snipped-for-privacy@snyder.on.ca wrote in

Fine if you want a KLUDGE. the next owner will probably not know what to do with it,when a problem occurs with it.
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Jim Yanik
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