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toodle_pipsky
09-13-2009, 08:32 AM
Well we're getting down to the business end of construction time. Woot! I was putting together mini trees and getting ready to remove the controller from the lights. Long story short the lights are LED and run off 14VDC from the output of the controller.

I couldn't find a power source to generate 14VDC. So I bust open the controller to modify it because there's a few threads around talking about it. Great, it doesn't look like any controller with pics posted before and I can't make the destructions given marry with what I'm looking at. Ugh.

So here's dumb dumb asking for help again. What parts do you think I can remove/jump to keep the 24VAC --> 14VDC but remove the 8 function blinky?

LabRat
09-13-2009, 09:11 AM
So you just want to stop the internal controller on the device from triggering? Here's my "best guess".

If you want these to be an "always on" string, then look at jumpering
each of the gaps as indicated by the RED arrows.

If you want to use the on-board transistors to act as your SSR board, then
you will want to connect at the yellow points. (The base of the transistors)
You will have to probe with a meter to see if these are pulled low or high in order to turn the lights on. Note that for *THIS* board they appear to be in pairs, and you should probably gang them together that way. If you were to
cut the traces marked with the BLUE arrows.. this could be a 4 channel SSR.

Well... that's MY guess anyways.

;)



Well we're getting down to the business end of construction time. Woot! I was putting together mini trees and getting ready to remove the controller from the lights. Long story short the lights are LED and run off 14VDC from the output of the controller.

I couldn't find a power source to generate 14VDC. So I bust open the controller to modify it because there's a few threads around talking about it. Great, it doesn't look like any controller with pics posted before and I can't make the destructions given marry with what I'm looking at. Ugh.

So here's dumb dumb asking for help again. What parts do you think I can remove/jump to keep the 24VAC --> 14VDC but remove the 8 function blinky?

kostyun
09-13-2009, 10:50 AM
Did a little bit of photo editing - and labeled a few things - I am curious - is this designed for a 12vac or 24vac input? It almost seems as if it should be 12vac.

The AC itself is run through a full wave bridge rectifier - therefor prodviding your DC.

http://www.doityourselfchristmas.com/forums/attachment.php?attachmentid=4590&stc=1&d=1252852611

christmas-light
09-13-2009, 01:30 PM
Hi

You youst have to soldering the greay pant I have made on the picture. ;)

I do the same whit thoes form ebay :p

C - L

toodle_pipsky
09-13-2009, 05:56 PM
Did a little bit of photo editing - and labeled a few things - I am curious - is this designed for a 12vac or 24vac input? It almost seems as if it should be 12vac.

Well smarty pants Frank with his diagram editing :) My bad - I originally said 24VAC - it is in fact 20VAC input. Thanks everyone, I'll have a crack at this tonight.

toodle_pipsky
09-14-2009, 08:21 AM
Ooook - tried what christmas-light (and I think - sorry that's me missunderstanding your diagram) Labrat suggested. By my multimeter, that's increased the output by 5VDC, from 14VDC to 19VDC. So what does that mean?

TimW
09-14-2009, 08:57 AM
Hi TP
How are you measuring the voltage at the output of the controller? These controllers work a bit like our other controllers in that they use a PWM waveform to dim. This could mess with your voltage reading unless you've got it fully ON (and even then its going to depend on whether the controller sets 'fully on' as straight DC.

Another thing to check ... are you sure the AC supply is an AC supply and not a 20V DC supply?? Give a couple of diode drops for the bridge and you'd be somewhere near 19V

How many leds in series in the string?

Tim

g2ktcf
09-14-2009, 09:08 AM
Well we're getting down to the business end of construction time. Woot! I was putting together mini trees and getting ready to remove the controller from the lights. Long story short the lights are LED and run off 14VDC from the output of the controller.

I couldn't find a power source to generate 14VDC. So I bust open the controller to modify it because there's a few threads around talking about it. Great, it doesn't look like any controller with pics posted before and I can't make the destructions given marry with what I'm looking at. Ugh.

So here's dumb dumb asking for help again. What parts do you think I can remove/jump to keep the 24VAC --> 14VDC but remove the 8 function blinky?

Toodles...is that an honest to goodness COMMERCIAL BOARD? That is horrible...you could do better making your own! lol

toodle_pipsky
09-14-2009, 09:40 AM
Hi TP
How are you measuring the voltage at the output of the controller? These controllers work a bit like our other controllers in that they use a PWM waveform to dim. This could mess with your voltage reading unless you've got it fully ON (and even then its going to depend on whether the controller sets 'fully on' as straight DC.

Another thing to check ... are you sure the AC supply is an AC supply and not a 20V DC supply?? Give a couple of diode drops for the bridge and you'd be somewhere near 19V

How many leds in series in the string?

Tim

Hey hey Tim,
Little controller set to steady on (I noticed the numbers flickering and dancing when it was set to any thing else :) ). Transformer is labled "AC-AC Adaptor" complete with squiggly line symbol. And I can't confuse this transformer with any other one I have since the plug that goes from lights to transformer is different to anything else I have. And there's 7 leds in a series.
Thanks for your help!

Thanks Chris - methinks you give me waaaaay too much credit.

TimW
09-14-2009, 10:21 AM
oh.. forgot to ask led colour....red?

(I'm working backwards here.... if we know the preferred forward voltage across the Led and multiply by 7....... for a 2v red led its 14V but for a 3.4V Blue it would be...23.8V )

christmas-light
09-14-2009, 10:29 AM
Ooook - tried what christmas-light (and I think - sorry that's me missunderstanding your diagram) Labrat suggested. By my multimeter, that's increased the output by 5VDC, from 14VDC to 19VDC. So what does that mean?

but did it work :p

C - L

kostyun
09-14-2009, 10:30 AM
My guess is white or multi-colored LED's.

20vac x 1.2 (recitified) is roughly 24 vcd.

toodle_pipsky
09-14-2009, 05:51 PM
Everyone's right! I have the same lights in blue, white and multi. And it was a multi coloured set that I've been looking at for this.

I'm looking at the box and as much as a box can be trusted, here's what they reckon the specs are:
Input 240V
Output 20V 4VA
Bulb Rating 3V 0.03W (bulbs cannot be replaced)
Total Wattage 2.88 max

And it gives the same for all colours. They're a black set, so I can't see what resistors they're using (in a clear set I have you can clearly see what the resistors are).

So you think it might just be easier to ditch the controller and work on what we know about LEDs?

PS - christmas light, when I got the different reading I didn't test the lights, but it didn't go bang!

TimW
09-15-2009, 09:34 AM
TP ,

To answer the question... I reckon just go with the mod as suggested (to get the power). There are a couple of possible reasons your multimeter readings vary the way they do. I doubt the DC waveform is very 'flat' and that will be confusing things. You need a scope to be sure.

If the box is basically saying 3V/'bulb' (well, nominally....) and 7 in a string its nominally 21 volts.... you're in the ballpark with a 20V AC supply full wave rectified (provided there's a current limiting resistor ).

I doubt the mod will give you a higher peak voltage than the leds already see.

If I'm wrong... well you may lose a strand.... (sorry about that!). But I'd try it if they were mine.... ;)


Tim

toodle_pipsky
09-15-2009, 06:00 PM
Coolio - thanks for the advice Tim. These are my super all time lucky find lights, only $5 from Dick Smith, so I don't mind losing a strand.

Thank you all!

joshlisa
09-20-2009, 05:17 AM
Toodles,

Last year I stuff arsed around changing those pesky little controller boxes and ended up with a very successful pile of spaghetti.
This year I lashed out and bought two very large 24v ac transformers. I have then put in bridge rectifiers and totally got rid of the controller boxes.
Looking at your controller board the two resistors at the top are for the two channels out and I simply removed them, Soldered them out near the first led in each string and heat shrunk them.
I have put in a little more effort in set up this year for good reason but more of that to come soon. Watch this space..;)
I guess what I am saying in a long winded way..Swap out the controller box for a bridge rectifier (changes ac to dc for all intents and purposes) and put the resistors in line...Easier in the long run.
Just my two cents....
Josh