huck1199

Use the red wire to the resister along with the black. Don't worry about the sense wire for now.

myrddin

Just picked up the resistor... I will let you know in about 10 min

myrddin

No good... I have black and green together... I have red to one side of the resistor and black to the other. I have all the yellow grouped together and comboned at teh end, I have done the same for the black... I have capped off every other wire so they are not connected or touching. I plug it in and the fan moves a bit and stops. I can keep it plugged in and take the green and the black wire and tap them together and it will light and spin for a second and stop and many times as I touch them together. nothing.... just spent another 14 bucks

any ideas?

Andrew

The Power_ON rail is green and must be connected to ground (black), either directly if you're going to use the AC master switch found on some supplies or thru a switch. Some supplies will latch without a load; some will not - there is no consistancy although many of the newer supplies will latch. Even though the supply may power-on without a load, output under load will be more stable if you either add a pre-load resistor or 1157 bulb or equivalent. The best way to determine if your supply has a sense wire is to check the motherboard connector - any pins with more than one wire attached is indicative of a sense wire and this must be reattached to the appropriate rail during the conversion.

Fan bumps are fairly common. I'm attaching a pdf file I send out to folks that covers some of the causes with solutions.

andrew

[link=http://web2.murraystate.edu/andy.batts/ps/POWERSUPPLY.HTM]Power Supply Conversion[/link]

myrddin

I have checked to be sure but there are no sense wires, only the green which I have connected to a black. I do now have a 10/10 resister on a red/black. it will not do anything... reading your PDF now.

myrddin

OK, I disconnected all the wires. I checked each for continuity... All was good... I plugged it in and then tested the yellow and black it beeps so that tells me its a short to ground but only when there is power? not sure if that is right.

jrowles91

Can anyone tell me how I blew the little glass fuse? Red, Yellow, Orange and Black wires all bundle and soldered to separate posts. Blue, Grey and Purple snipped short and shrink wrapped separately. 1 Red and 1 Black connected to opposite ends of 10w/10ohm resistor. The only Green and 1 Black for power on. As soon as I turned on the PS the fuse popped. Any help would be greatly appreciated now that I've destroyed this PS.

Below is a picture of the unit. You can see just about everything.

http://www.rcuniverse.com/gallery/ga...berID%3D479503

BTW how do you get pictures to show up on the post without using a link like this. I've hit the image button but nothing.

jrowles91

lol well I guess it worked. Why doesn't it show working on the Preview? oh well.

jrowles91

UPDATE: I took the case apart and found the ground cables had come loose and were probably touching the case. Could this be why the fuze popped? If so can I replace that fuze or is the PS junk?

Andrew

Generally, no from touching the case; touching something else may have been the culprit.

However, in one of the photos, the lead from the resistor appeared to be touching the heat sink - that may have also caused the fuse to blow. These leads should be covered either with heatshrink or a piece of insulation from some 16 to 18 ga. wire and should not come into contact with any part of the PSU. On many supplies, these heatsinks are hot and you can get an AC jolt if you touch the sink and case at the same time [X(].

The fuses are replaceable - yours appears to be soldered in. When you get it out, check the rating on the metal ends and replace with an equivalent fuse.

andrew

jrowles91

Ok so move the resistor and cover the leads completely (btw the leads are NOT touching the heatsink), replace the fuse and it should operate? From what you can see and what I explained, the wiring seems correct? Also yes the ground could have been laying on the 3.3v or 12v connector also, just not sure.

TedWS

lbarnes

Maybe I'm missing something here, but the power supplies that I have laying around have all the yellow, red and black wires soldered to the same location on the mother board.

This would tell me that I dont need to solder all the yellow, red and black wires together. Just cut all but 1 wire for each color and run to a jack.....

I did read somewhere on another post and forum that you will increase the amp output by paralleling the 12 and 5V outputs.

If they all go to the same location on the mother board paralleling the wires will do nothing.

Larry

Andrew

Using 2 (or more) wires on the same rail to one jack does not effect how the PSU functions. What is does do is ensure that there is a minimal voltage drop and maximum current carrying capacity between the circuit board and associated jack. I have seen a 400 watt supply (which I suspect was grossly overrated) with 22 gauge wires for all rails. Although the Design Guidelines specify 16 AWG for high wattage supplies, most have 18 AWG as the standard.

If you want to pull a continuous high amperage current on 18 AWG, feel free. Most folks double up just to improve current transfer.

andrew

lbarnes

I respect that.

If your going to pull max amps then yes the bigger the wire the better.

But I have seen it posted on some BBS the if one yellow wire is 10 Amps the 4, yellow wires soldered together are 40 Amps...[:-]


Since the output is posted on the side of most power supplies, that should be the MAX you can draw.

Just my $.02 worth...

Larry

Andrew

You're correct - that's just bad information. There would be a lot of happy folks if it were true.

Realistically, many of the less expensive supplies are probably overated - the spec. placard is an optimistic rating, but at absolute best, the MAX as you noted.

andrew

dmartin2010

Is there anyone that would be willing to build we a power supply?. Im running Turnigy 30-40c discharge 4s packs. Would like the option of charging at 4c but will probably do 3c to be safe. I have a iCharger 208B which is 20a/350w max. I am capable of building the power supply myself but would rather not. If someone is willing I would like this done but only with a decent power supply (not a 30 dollar psu for example) an Antec, Cooler Master or something along those lines. Any help would be appreciated.

lbarnes

Why not go on Ebay and look for the mainframe power supplies. You can find them for about $50.00. They are rated at 12V, 50A.

Our club purchased 2 of them last year for our field charging station.

Larry

dmartin2010

I would still need to open it and convert so I could use it wouldnt I?.

lbarnes

No conversion needed. you just hook up the wires to the output terminals and you good to go..

Your thinking of a personnel computer power supply.

This one is a 30A 12V switching power supply, but bigger ones are available.

http://cgi.ebay.com/Regulated-Switch...item483dbb2f8a



Larry

dmartin2010

ok so ewhat exactly do I search for ? Im clueless here.

lbarnes

Well, click on the Ebay link in the last post and then you can go to the category (dc power supplies) that will get you into the proper page. Do a search for 12 V power supplies and you will see the listings.

Or if that power supply is going to work for you, just buy it

Larry

dmartin2010

ok so between the one you showed me and this one

lbarnes

It's up to you. Either one would work. The one you found is about $3 cheaper in price.

I cant tell if one is better than the other by manufacture. Just about everything is made in China now a days....

You may want to ask about the warranty...

We have not had any issues with the 2 we bought last year, but I could not find them on Ebay. I guess the 50A are all gone.

Larry

OldRookie

My Feedback: (13)

Try this one. A little higher price, but you are guaranteed that it is manufactured, and carries the Meanwell brand name. This is the one I use, and I use my computer power supply that I built as a back up. Some of the converted computer power supplies will make some chargers get a false peak, and terminates the charge prematurely.

If you get one of these, make sure you select 120V, on the AC input voltage switch. I also replaced the cheap two wire cord that is supplied, with a 3 wire cord.

http://cgi.ebay.com/12V-DC-29A-350W-...item19c31eb598

Greg