[RE-wrenches] Low wattage 120vac to 24vdc transformer for LED's

[James Jefferson Jarvis]

It's called a switching power supply. There are thousands and thousands 
of different models. Typically universal input voltage (80 to 300 volts 
AC, more or less) and DC output. Should be in the upper 70's to mid-90's 
percent efficiency.

Mean Well is a decent quality brand. Prices are good. Buy from Jameco.

Just put it at the beginning of the circuit that feeds all your lights. 
Power supplies are efficient when they are loaded. With no load, 
efficiency drops to 0%. Like idling your car at the stoplight ... 0 MPG.

My house is all low voltage DC lighting. I have a single 200 watt power 
120VAC to 24VDC switching power supply that runs everything in the house.

-James Jarvis
APRS World, LLC

On 1/29/2015 12:58 PM, Dave wrote:
> We are renovating a 25 yr old off grid house and one of things being
> done is to change some 24vDC circuits to 120vac. The only problem that
> I'm having is finding a low wattage 120vac to 24vdc transformer for a
> few strings of 24v LED night lights (a few watts each string) that are
> built into some nice hardwood trim in the bedrooms.
>
> I just tested the following device and found that it uses 29 Watts to
> power a 3W LED. Not an acceptable load for this house. It is labeled as
> LED Magnetic Transformer by National Specialty Lighting part #
> TR24L20DC-M20L24DC-AR Input: 120vac, Output 24vdc, Maximum 20W
>
> Is there anything else available that will do this job and use a lot
> less power than 29 Watts?
>
> Thanks,
>
> Dave
>
> David Palumbo
>
> Independent Power LLC
>
> 462 Solar Way Drive
>
> Hyde Park, VT 05655
>
> 802-888-7194
>
>
>
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-- 
-James Jefferson Jarvis
APRS World, LLC
+1-507-454-2727
www.aprsworld.com