Re: Worst soldering job ever??

My word, my soldering looks class compaired to some of those - and I am a bit of a numty!

Re: Making a small high power LED array - best way to drive them?

OK guys, the LED's came today and I've been having a little play with them. Like them so much I'm going to get the 12v versions so they are easier to drive.

Only problem really - apart from they need loads of juice, is that there so small. The die is only 2cm square. Packed into that is a matrix of 3X3 LED's, cooling them down is problematic...

Got a small vid to show you guys, bear in mind this is only two LED's done Mguyver style. The lights are near the center of the tank and they are...

Re: Making a small high power LED array - best way to drive them?

OK, so I'm going to knock the step up boost converter on the head. Would be fine for lower power leds but its just not suitable. might get one though as they seem handy as a small bench psu type thing.

Going to go for an off the shelf driver, and I will run three - one for each led. Finding a driver with enough volts was difficult!

Anyway the specs are:

input Voltage: AC85V-265V
Output Voltage: 27-30V (10W)/30-36V (20W/30W/50W)
Input Current: 0.2-10A
Output...

Re: Making a small high power LED array - best way to drive them?

Sorry guys, I got the V/C mixed up when accumulating. The idea of using the dc/dc boost controller was so that I can regulate current or voltage (does both i think) this is the digital one, you can get a cheaper one with pots on which does the same thing.

[URL="http://www.ebay.co.uk/itm/DC-DC-400W-8v-80v-10A-Digital-controlled-Boost-Step-up-Module-Power-Supply-/111160407480?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item19e1ad35b8"]http://www.ebay.co.uk/itm/DC-DC-400W-8v-80v-10A-Digital-controlled-Boost-Step-up-Module-Power-Supply-/111160407480?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item19e1ad35b8[/URL]...

Re: Samsung le19r86wdx - Noise

Thanks Tom66 - I'm going to see if I can get a known good board from Ebay Do you know if I will have any problems using a newer revision board like we would have got if I used the newer rev board on the plasma we fixed?

Plasma is still going btw

Re: Making a small high power LED array - best way to drive them?

Hmm I'm willing to learn and maybe its because its really late here 12:30 but some of that goes well above my head

The LED lights only cost 4.99 for five, am I right in thinking that if I bought the 12v versions = Voltage 9-12v current = 900ma

I could just simply run them off of a dc/dc boost converter in series @ 12v - 2.7 amps, well within spec with an off the shelf psu and not having to worry about different I/V of chips?

Thanks

Re: Making a small high power LED array - best way to drive them?

^^ @ Tom AH bugger, I was hoping the diagram below would work

[/URL][/IMG]

I guess the easiest to work with is to get the 12v LEDS and drive them off of a boost controller in series?Re: Making a small high power LED array - best way to drive them?

^^ @ Tom AH bugger, I was hoping the diagram below would work

[/URL][/IMG]

I guess the easiest to work with is to get the 12v LEDS and drive them off of a boost controller in series?Re: Making a small high

Re: Making a small high power LED array - best way to drive them?

Just read through your post @mariushm

What an awesome idea, the LED's are going to be connected to a large piece of aluminum which acts as a lumair/hanger with some regulated computer fans so cooling wont be a problem (I think)

All I need are one of these and to mount the regulator/driver on the heatsink with the led's (so simple!)

Do the semiconductor run @ the full 350ma without changing the Radj?

Much thanks!

Re: Making a small high power LED array - best way to drive them?

Thanks for the information @mariushm

Re: Making a small high power LED array - best way to drive them?

Thanks for the info tom, I've now found there's two types of these dies. One has the specs above, another has a 12v feed with increased current - guess the 12v one will be easier to work with off the shelf parts.

Damn it, Ill have a little play with them when they get here and see how I get on, is there anyway a mortal can see the I/V characteristics of a die? I suppose if the I/V is close you could run them in parallel without a ballast resistor?

Re: Making a small high power LED array - best way to drive them?

OFc, thank you. Though in my previous post I think I made a mistake about wiring them in series - the voltage will be out of spec for the stepup boost converter. I will have to wire them in parallel at just over 1amp (I think)

The link is below, I think they have a chip on them (IC led floodlight) I thikn COB is "chip on board" ?

[URL="http://www.ebay.co.uk/itm/251406491858?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649"]http://www.ebay.co.uk/itm/251406491858?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649[/URL]...

Re: Making a small high power LED array - best way to drive them?

^^ Ah sorry Tom, your right. I was looking through Ebay and might have got the wrong link.

Though in the description (Chinese language barrier perhaps?) it does say its a "DC-DC 400W 6-40V to 8v-80v 10A Boost Converter Step-up Module Power Supply" (confused)

Anyway the one I was thinking about was [URL="http://www.ebay.co.uk/itm/Digital-led-400W-10A-DC-DC-constant-voltage-constant-current-DC-boost-Converter-/281175791194?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item417762165a"]http://www.ebay.co.uk/itm/Digital-led-400W-10A-DC-DC-constant-voltage-constant-current-DC-boost-Converter-/281175791194?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item417762165a[/URL]...

I'm going to make a simple high power led setup for my aquarium, I just need to figure out the best way to drive them.

The array is going to be made up of two or three 10w COB leds, specs are below...

Voltage: DC 32-34V
Current: 350mA
Power: 10W

I could get a driver for each of them, but I can only find simple 12v dc ones. I was thinking about using an old laptop charger and running it though one of these:

[URL="http://www.ebay.co.uk/itm/Digital-controlled-Constant-Current-Voltage-LED-Driver-Step-Down-Power-Module-T1-/271286006158?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item3f29e7f18e"]http://www.ebay.co.uk/itm/Digital-controlled-Constant-Current-Voltage-LED-Driver-Step-Down-Power-Module-T1-/271286006158?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item3f29e7f18e[/URL]

Re: Samsung le19r86wdx - Noise



Sounds good mate, thanks for saying

On another note i've been looking at some later revision boards and apart from having different caps there are two big changes..

Ether side of the inductor there are two yellow boxes and they have been changed to blue one in the later revisions. It might be clutching at straws but it does seem to be in the area of noise.

I wonder what those boxes are and if they could make a whining noise?...

Re: Samsung le19r86wdx - Noise

Well, just to try I swapped the inductor over. no change. But as you said Tom the board could have the same fault.

I could try using some epoxy on it, not got varnish. Will the epoxy be ok for heat?

Re: Samsung le19r86wdx - Noise

^^ Hi again Tom, I had nothing to loose and swapped it over before dinner cant really tell if it produced a change or not, though I don't think the sound is coming from there (hard to say with high frequency sounds)

From what I can gather there is a noise coming from the transformer area and there is another noise coming from the area below. The noise from the transformer at the moment is bearable. Though the noise coming from the area below is the "kettle coming to a boil" noise and it quite often changes pitch (not related...

Re: Samsung le19r86wdx - Noise

^^ Thanks a lot for your help Tom, I think that I will swap the part around from the two boards for now and see if it changes the noise at all.

Looking at the two boards, the part in question has no markings for positive and they are soldered on the board in opposite ways.

What i mean by that is on one board the writing is facing the large 450v capacitor and on the other the writing is pointing away from the cap.

I suppose it does not matter which way round the small cap (C 106) is soldered?

Re: Samsung le19r86wdx - Noise



Hi there, thank you for your input.

I think the board is bn44-00152b S/N number is :CN08BN4400152BSE38B5NA193

I located the part described (in front of a large cap) Part is labeled: B 102k 1kv

If that sounds right I have a spare one on the old board or I can buy a new one, problem is I don't know what on earth it is and if I bought a replacement, I wouldn't know whether to get the same spec.

Would it be possible to ask what it is, and is it worth buying a new one or will replacing...

Re: Samsung le19r86wdx - Noise

OK, strange turn of events. got myself a borked board on the cheap and replaced the transformer over with my noisy old board...

No real change in the noise, the noise still seems to be coming from the transformer - I find it odd that two transformers exhibit the same noise?

Anyway, could there be anything "out of spec" on the board which causes a strange whistling noise?

Cheers in advance.

Re: Samsung le19r86wdx - Noise

Just cooked it, I thought the heat wrapping of the tape might have melted and quieten down the coils. I don't have any varnish to hand which is a bummer.

On the bright side I didn't kill the transformer and it still works, I'm afraid I'll have to bite the bullet and source another transformer or board (quite likely not to too far off the cost of a pot of varnish @ bnq)

I'll have a phone around and see if i can liberate some.

Thanks