Where do I get my 12v from? DK restore

[Neilyboy]

Alright so im somewhat close to finishing my DK cab. I have installed one of GGG's Nova Matrix LED marquee lights. I am now wondering where to I get the needed 12v from? I know I could just cut the yellow or green wire from teh 9P CPU harness and splice it in there but I would rather not splice the harness.
What I am wondering is since I am not using both of the 100v plugs off of the original nintendo power supply. Would I be able to plug in a 12v transformer block say off of an old router or something that outputs 12v or would this not work (here is where I dont know much about electricity). I was hoping to be able to just cut the end off of an old router power block and attach the wires directly to the nova matrix. I know the transformer would be expecting 120v then converting it to 12v out for the 'router' or in my case nova matrix but would it still work as long as it is getting ~100v?

Anyway, what is my best bet at doing this asides from installing a switching power supply just for the marquee light.

Thanks so much in advance,

Neil

[BobA]

Be careful if you are using a wall wart from other equipment to power the light.  I used a 12V one that was supposed to be regulated but it was more than 14 V even with load.   According to Randy this would damage the LEDs iin a very short period of time since they are optimized for 12VDC regulated.

In my case I added some (IN4004) diodes in series with the supply lead.  This brought the voltage of the wall wart down to an acceptable 11.8V.  You may have to experiment with your setup to determine how to get the output of your wall wart to 12V.   You could also use a 3 terminal regulator such as a 7812 and a higher voltage wall wart  to provide a regulated 12 V.  I used a wall wart rated at 12V and 600ma.

Since wall warts are usually a small transformer you will loose about 20% of your output voltage plugging into the 100V ac transformer.  This may give you an unacceptable output voltage depending on how it is rectified and regulated internally.   The only way to tell is to plug it in and measure the voltages.  Remember you need 400ma for the NM Leds.

[Neilyboy]

Thanks a ton for all the info BobA! I do have a multimeter so I will check it out. I know for sure the meter will read voltage but is there a certain spot on the dial to check for (ma) readings?

I assume that if I am able to plug a 'wall wart' into the 100v plug on the nintento power supply as long as its spitting out ~12v give or take .2v at 400ma then I should be ok in throwing that into the nova matrix.

thanks again Bob!

Neil

[Neilyboy]

is 1A (amp) 1000mA  (milli-amps) by chance?

Cause I was able to find a plug that says 120V/12VAC 1A
and one that reads 12VAC 1250mA (So im guessing both of these are too much)

I also found a Linksys Wireless Router Power adapter that says "Output: 12V DC 0.5A" so would this one be my best bet?
This would probably only give me like 9.5v but at 400mA (correct?-if plugging into the existing 100v power off nintendo block)
So what If I were to splice into my 120V input from the wall before it gets to the nintendo power supply could I then just splice into it and rig a jack out of it for this linksys adapter to plug into?

Neil

[BobA]

You don't have to measure the ma.  Just make sure the wall wart is rated high enough to supply your requirements.   1A is 1000 ma and .5a is 500 ma. Too much does not matter when rating a wall wart.  It just gives the max capacity of the unit.  Your leds will only take as much as they need.

You can splice into the 120V before it reaches the transformer and get a full 120 to feed your wall wart.  The best place to do this is at the terminal strip where the 120 cord hooks into your cabinet.   With this type of voltage your best way to tap in is using the same gauge of wire and following the blk/wht/green color scheme wire is a 120V outlet housed in a metal outlet box just like the one for 100V.  Be sure to label the new outlet as 120V as there are different ac voltages in your DK cab.

[Neilyboy]

Thanks Bob you are the man!! So as long as I am able to supply no more than 12v to the nova matrix it shouldnt hurt the led's correct.

thanks again.

Neil

[BobA]

Right 12V or a bit less.  Do not go over as the heat and stress on the LED is apparently exponential.