if you will look at the different power supplies you will see the
difference. The LED lights require dc power (note the transformer says
output 12vdc). teh exisiting transformer you have is marked output
12vac. To use it you will need a rectifier unit to change from ac to
dc. something similar to these.
http://www.radioshack.com/product/index.jsp?productId=2062583&cp=&origkw=rectifier&kw=rectifier&parentPage=search
http://www.radioshack.com/product/index.jsp?productId=2062584&cp=&origkw=rectifier&kw=rectifier&parentPage=search
http://www.radioshack.com/product/index.jsp?productId=2062582&cp=&origkw=rectifier&kw=rectifier&parentPage=search
note, you may need to mount these on a heat sink if carrying much
current. according to the marking on the LED transformer you have, any
one of these should be able to handle several LED strings, since they
draw less than 1/2 amp.
Ian wrote:
> Hi All,
>
> Here's what I'm trying to do: I have a built-in wall unit that has existing
>12V spotlights using a 300W transformer (see 12VTrans pic link below) that has
>a lot of excess capacity (only using 60W of it). I'm adding LED strip lights
>that are also 12V and come with their own little power supply (see LED pic
>links below). I'd like to cut off the LED strips power supply and just wire
>them into my existing transformer that is controlled by a dimmer on the wall.
>
> The problem: I wired the LED strips into one of the open 60W transformers
>(the 300W 12V unit is actually 5 individual 60W magnetic transformers). It's
>a magnetic transformer so it dims nicely with the wall dimmer. However, the
>LED lights will not work. At full power on the dimmer the LEDs come on at
>normal brightness for a fraction of a second, then they dim to maybe 10%
>brightness and stay that way. As I adjust the dimmer they don't get more than
>maybe 20% brightness. Using the LED power supply, they are full brightness;
>they only come with an on/off switch, no dimmer. Does it sound like the LED
>light strips have some sort of electronic circuit on them that doesn't like my
>12V magnetic power supply, as even at full power (no dimming) they aren't
>working?
>
> I'd love to have these strip lights wired into my existing transformer, but
>in lieu of that my plan is to just use their original power supplies and give
>up on dimming them. If anyone knows how I can make them work or can even just
>explain why they don't work, I'd appreciate the insight.
>
> http://i17.photobucket.com/albums/b98/ianmcfetridge/LEDstripsps800x600.jpg
>
> http://i17.photobucket.com/albums/b98/ianmcfetridge/LEDstripsbox800x600.jpg
>
> http://i17.photobucket.com/albums/b98/ianmcfetridge/12VTrans800x600.jpg
>
>
> Thanks, Ian
>
--
John
another one of them
*.?-!.* cub owners
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