Need a good 30 volt switching power supply

[sam_sam_sam]

Where can I find a good 30 volt switching power supply or a 24 volt switching power supply I can do a mod to and change to 30 volts @ 1 amp or better

I am going to use some 100 watt LED modules as yard lights and need a power supply form them

These thing are VERY BRIGHT

Thanks to any one that can help

[stj]

Re: Need a good 30 volt switching power supply

your doing it wrong, you dont regulate the voltage for that job.
you need a regulated current psu.

there are lots on ebay once you calculate the current to drive your leds.

[PeteS in CA]

Re: Need a good 30 volt switching power supply

What stj said! I worked briefly at a place that made power sources for LED street lamps, and LED are indeed current-operated devices. You need a constant (regulated) current power source. That said, you might begin by checking Digikey, Newark and Allied.

[mariushm]

Re: Need a good 30 volt switching power supply

Like the people above say, you need to control the current going into the led, not the voltage.

That kind of "lightbulb" is made out of lots of blue leds in series, and then there's potentially several of those chains of leds in parallel. The whole matrix is covered in phosphorus to produce white light.

As the whole thing runs, it will heat up. As with any diode, the voltage drop on each led will change with heat so if you feed the led matrix with a fixed voltage, you may break it by giving it too much "juice"

When you buy a led from eBay they're giving you a voltage and a current. That voltage is just an indication... the current is important.

For example, if a led says 30v and 1A you would use a led driver that would constantly adjust the voltage around 30v so that there's always 1A flowing through the led.

There's BOOST drivers which will take a lower voltage from a power supply and raise the voltage up or down controlling the amount of current, and there's also BUCK drivers which take a higher voltage and output a smaller voltage, enough to reach that current limit.

So depending on what led driver you pick, you can use various power supplies.. for example you could get a 24v switching power supply and use a led driver to boost to about 30v @ 1A, or you could get a 36-48v switching power supply and use a buck led driver to get down to about 30v @ 1A.

Here's an example of ready made led driver, it accepts anything between 7v and 36v DC and outputs exactly 1A of current to whatever led you connect (up to 31 watts) : http://uk.farnell.com/recom-power/rc...33v/dp/1793224

Lots of other ready made drivers here : http://uk.farnell.com/dc-dc-converters-led-driver

Replace uk.farnell.com with newark.com , it's the same online store (same company) but they use newark.com domain for US sales. There's also digikey.com or mouser.com for US people.

If you want to make your own driver, you can buy chips and follow the schematic in datasheets to built circuit.

Though in the end... keep in mind that such leds will be very hot very fast, you'll need quite a large heatsink and potentially even a fan moving air over the heatsink to keep the leds at a normal operating temperature.

[budm]

Re: Need a good 30 volt switching power supply

Some readings:
https://www.badcaps.net/forum/showpo...&postcount=121
Coolings:
http://www.edn.com/electronics-blogs...assive-methods
http://www.ledsmagazine.com/articles...-magazine.html

http://www.electronics-cooling.com/2...n-led-cooling/

[sam_sam_sam]

Re: Need a good 30 volt switching power supply

I will have some reading to do I want to thank everyone who posted to this question

[PeteS in CA]

Re: Need a good 30 volt switching power supply

There's also digikey.com or mouser.com for US people.

I keep forgetting Mouser. Back in "ancient times" (Nixon was President of the US) Mouser was basically selling surplus and floor-sweepings parts. I think Jameco is a modern seller of surplus electronic stuff.

[stj]

Re: Need a good 30 volt switching power supply

i want a datasheet for that led, i'v only seen them upto 50w - and they werent cheap!

[mariushm]

Re: Need a good 30 volt switching power supply

There's lots of them on eBay, they're cheap but they're mostly of dubious quality and reliability.

Basically, the color temperature could be wacky (2400k instead of 2700k for example), the view angle could be lower, the CRI may be very low (let's say 65-70 instead of 85-90 for high quality leds... if you light up a room with leds that have low cri your eyes will see screwed up colors), maybe they failed test due to too high voltage drop/overheating and so on.

Farnell / Newark has a lot of these leds, from 75-100mA to tens of watts... I personally played with some high CRI 8w leds (19v 0.5A) that were about 10$ each and they were worst every cent.
Here's a link (change to newark.com to get the US site) : http://uk.farnell.com/webapp/wcs/sto...owResults=true

[kc8adu]

Re: Need a good 30 volt switching power supply

those things need a big heatsink too.even then they fade fast.
ebay is full of these cheap things and the drivers for them.

[sam_sam_sam]

Re: Need a good 30 volt switching power supply

Here is the link to the E-bay seller that I bought two them from
http://www.ebay.com/itm/121363517173...%3AMEBIDX%3AIT

One foot note these LEDs are very bright even at 200 milliamps and real bright at 1amp but I only for less than 5 seconds at that power

[stj]

Re: Need a good 30 volt switching power supply

the Lumen's on that are only about the same as a flourescent tube.
10,000 Lumens for 100w led.
i have 5200 Lumens on a 58w tube here.

[kc8adu]

Re: Need a good 30 volt switching power supply

remember those are chinese lumens.
if it does 2000 i would be shocked.
and as i stated earlier the lumen maintainence stinks!

[kaboom]

Re: Need a good 30 volt switching power supply

remember those are chinese lumens.
if it does 2000 i would be shocked.
and as i stated earlier the lumen maintainence stinks!

not to mention a CCT of 8000 and a CRI of about 12