Using LED power supply to run incandescent bulbs

Graeme wrote on 18/08/2017 :

Maybe you could make use of the base of the original failed lamp, to make up some ready to use LED replacements? As one fails, screw in a ready made LED version.
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wrote:

As silence doesn't seem to be essential and there is plenty of room to hide them I'd use old computer ATX PSU's. They have the advantage that they can be switched on and off easily using the low voltage control built into them.
I've got a spare DPS 750 server PSU (details at
https://static.rcgroups.net/forums/attachments/3/1/3/5/4/3/a4388405-162-Delta%20DPS-750BB%20PS%20Full%20Pinout.jpg ) This will supply 12V at 36 Amps all day so about 350 of your bulbs. If you are using the full 750W the fan is loud, at half load it is pretty quiet. It also has 5V and 3.3V outputs also at 36A max (but total load must stay less than 750W).
It is big - 12 x 12 x 30cm and fairly heavy - 5kg
If its any use you can have it for the price of the postage (which should be less than £10). I can do the wiring mods for you.
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wrote:

And he said how to handle that in the bit you deleted from the quoting.

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Tim Watts wrote:

Just strap the green wire to a black one, that'll start it.
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Thank you for all the replies. I now understand why an LED power supply will be unsuitable.
However, this is brilliant :

I must have at least 4 old desktops here, not used for years. I'm guessing they will have power output printed on the label. I confess I did not know breakout boards existed. So, a power supply from an old PC, a board like this :
<http://www.ebay.co.uk/itm/24Pins-ATX-Benchtop-Power-Board-Computer-Power -Supply-Breakout-Module-Adapter-/332344315793?hash=item4d6143cf91:g:G8YAA OSwjIRZkm5e>
The answer to a maiden's prayer. I assume two wires, connected to 12v and GND, will supply all the little 12v bulbs I need, all wired in parallel. Perfect.
From memory, the power supply will come out of the PC complete with 'kettle' mains socket, cage, fan etc. all in one.
--
Graeme

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That should do it. However you should watch that the 24 pin 'ATX' connector has a limited current rating - I'd budget about 5A per pin[1]. There's only two 12V wires on the ATX connector so 10A available.
Most of the 12V current is intended to be supplied on the 'EPS' and 'PCI Express' connectors: http://www.playtool.com/pages/psuconnectors/connectors.html
So you might use the above breakout to supply other voltages and switch the PSU on, and then snip off and solder yellow/black wires to access more 12V current.

Yes. The outputs should be on the label. Note that some PSUs are split rail (12V1, 12V2, etc) so it's best to not to join outputs from different looms if you need more current.
Theo
[1] The official Molex pins are rated at 9A, but safer to assume they've underspecced the wiring (and to avoid pins getting hot).
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wrote:

LED power supplies are mostly constant current supplies, incandescent bulbs require constant voltage. The LED PSUs voltage can vary considerably as they try to keep the current stable (ish). A constant current PSU will have a specified output current much lower than its wattage rating would indicate - as you increase the load it increases the voltage. The rated current is fixed, the rated wattage is fixed, the voltage will vary to maintain the rated current within the power maximum. If you connect bulbs in parallel to the PSU then as bulbs fail the PSU will ramp up the voltage to maintain the current at a stable level. Incandescent bulbs really dislike over voltage so they will all start failing rapidly.
For example a typical constant current LED drivers provides 700mA output in power ratings of up to18W. It will automatically set the current output and allow the voltage required vary automatically to cover voltages from 3 - 54V as the load varies..
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Graeme wrote:

I've used lots of these for all sorts of jobs including driving electronics and motors in the same job. They are current limited and behave very well. The most recent one is powering a lift to raise a 1/4 tonne machine from its storage position to operating bench height based on the works from a motorised golf cart. A good cost effective PSU solution.
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On 17/08/2017 17:46, Bob Minchin wrote:

... snipped

That sounds very interesting - any more info, or pics?
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snipped-for-privacy@gmail.com wrote:

Yes it was an interesting project and a great sense of relief when the first lash up managed to lift my own weight with quite a small proportion of the PSU current being drawn! I wrote it all up for a woodworking forum but since the decision of Photobucket to apply extortionate charges that I refuse to pay, the photo links are all broken.
I'll try and dig out a working link to a video I took of it running.
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Bob Minchin wrote:

Here are the photos http://s115.photobucket.com/user/9fingersphotos/library/Planer%20lift?sort=2&page=1
and the text is here
http://www.thewoodhaven2.co.uk/viewtopic.php?f#&t 65
they are sort of in order. Hope you can make something of it.
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On 17/08/2017 22:01, Bob Minchin wrote:

Unfortunately my broadband is so slow here that I can't get to all the pics in a sensible time, but from the thumbnails it looks pretty impressive (and a lot of work). I talk about projects like this but there's a never ending list of things to do on the "new" house so engineering projects are shelved for the time being. I got the (2 tonne) lathe and (1/2 tonne) mill into the workshop this week (after far too long under tarps) but have now decided I want the lathe against a different wall so lots more jacking and rolling are needed - bu&&er!
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snipped-for-privacy@gmail.com wrote:

Glad you could make something of it. I've now fixed the forum links for the photos and as the forum auto scales the pictures it might load faster for you. Now I'm retired and time -rich I can embark on projects like this. Good luck with machinery move and hope the rust has not crept in under the tarps. My myford lathe and VMC mill are quite modest by comparison but still not relishing moving those anytime. Bob
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Bob Minchin wrote:

What's the tale behind the middle finger?
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Andy Burns wrote:

Not to be read at meal times!
It got attacked by a planer (a different one). Tendon transplanted from my leg, skin from my forearm and flesh sourced from the next door finger. The surgeon sewed the damaged finder to its neighbour which gave the transplanted flesh a blood supply (called a cross finger flap).
Whilst in that state, bandaged (and bored), I joined a different woodwork forum with the user name "9fingers". A few weeks later, the finger were separated again but if I had changed my user name to 10fingers, it would have led to even more questions! The (female) physio seemed a little taken aback when I said I really needed my foreplay finger working again! 12 years on my hands are fully functional but I still use the user name "9fingers" on a number of forums.
Well you did ask....
Bob
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Bob Minchin wrote:

Excellent. I had/have various relatives who lost one or two fingers to belts on farm machinery ...
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I have a nine-fingered friend who lost his when he jumped off a trailer in motion and his wedding ring caught on something on the trailer. I believe it's called a "degloving" injury. :oO
--
Today is Setting Orange, the 11th day of Bureaucracy in the YOLD 3183
I don't have an attitude problem.
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You aren't a Joe Abercrombie fan, by any chance?
http://firstlaw.wikia.com/wiki/Logen_Ninefingers
https://en.wikipedia.org/wiki/The_First_Law
--
Today is Setting Orange, the 11th day of Bureaucracy in the YOLD 3183
I don't have an attitude problem.
  Click to see the full signature.
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On 18/08/2017 11:34, Bob Minchin wrote:

An enjoyable 30 minutes has just been spent reading your project write-up - very impressive! I don't know how long it took, but it might have been faster to extend the workshop ;-)
One of the photos showed parts of your extraction system - I'll start a separate thread on the subject in the hope that you can describe what you've done
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snipped-for-privacy@gmail.com wrote:

I've replied to your extraction thread and posted a video
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