Ledengin 120V AC driver ?

[purduephotog]

I could use a little help here-

I'm a bit on the tired side of buying tons of 40W Xitanium drivers- they're getting very expensive.

What I'd like is a 120V AC line driver to drive 8x 10W Ledengin LZ4-40R210 (11.4V, 1A, 660nm deep red) LEDs in series.

If I pop over to Webench-
http://webench.national.com/webench...&ledparallel=1&source=AC&line_fsw=60&op_TA=30

Put in 8 in series, 1A, 11.4V, leave AC to the default range- and you get a solution.

You get 3 unique custom parts, Rsense which is 0.612 Ohm and an output capacitor 1uF, ESR=100uOhm, VDC=109.44V.

(Say what?)

Going from what I thought would be simple (parts add up to about 22$, give or take- most of the cost in caps).... what would it take to build this circuit?

At this point I'd be willing to pay someone else to finish the design (since I don't even believe the effort I've put into it is considered 'design').

Ideas? Comments?

 

[SemiMan]

AC designs, isolated, are not trivial. You need UL, CSA, CE, etc., FCC, DOC, VDE, etc. before you can ever put them into a product.

Webbench is designed to get you started... a way of comparing options, basic simulations, etc. It does not take care of EMI, emitter or susceptible, proper layout for effective operation, safety or EMI, transformer winding, etc., etc.

If you are buying under 10,000 pieces, in general it is better to buy off the shelf. Worst case, have an existing supplier slightly modify an existing design.

Semiman

 

[purduephotog]

AC designs, isolated, are not trivial. You need UL, CSA, CE, etc., FCC, DOC, VDE, etc. before you can ever put them into a product.

Webbench is designed to get you started... a way of comparing options, basic simulations, etc. It does not take care of EMI, emitter or susceptible, proper layout for effective operation, safety or EMI, transformer winding, etc., etc.

If you are buying under 10,000 pieces, in general it is better to buy off the shelf. Worst case, have an existing supplier slightly modify an existing design.

Semiman

Thanks-

Unfortunately I have not seen anything in this product range- a high voltage 1A LED driver. My choices are 40W Xitaniums or, rare if you can find them, 60W and 100W- but even then they're not really designed for these voltages so many go to waste.

I wasn't going to make a product, just something for home use.

Thanks for the thoughts- I hadn't thought about it in those terms.

 

[deeuubee]

I don't know if this is what your looking for, but I'm trying to wire up my 16 ceiling downlights with leds and one power supply.

I'm about to give these folks a call. I just found out about them, so I don't have much else to say about them except it looks like it's gonna cost me to do it right. :mecry:

They sell and make power supplies.

http://www.acopian.com/constant-current-power-supply-models.html

this is the other LED driver place I'm looking at

http://www.astrodyne.com/led-drivers/

 

[blasterman]

What I'd like is a 120V AC line driver to drive 8x 10W Ledengin LZ4-40R210 (11.4V, 1A, 660nm deep red) LEDs in series.

Watcha growin?

I have the same problem with Bridgelux. 9.8 volts at around an amp, and they suck up smaller current regulated supplies to the point it isn't practical to use them. Plus, I'm growing increasingly aggravated at Xitaniums and such for really big LED arrays because current regulation *isn't* mandatory.

We should really blame Nicola Tesla and his durn AC power for this, but I think I might have a more practical solution. I use computer power supplies for my Bridgelux because dropping 12 volts to 9.8 just requires a fat radio shack resistor, and run them in parallel. It's even easier in your case because it's 11.4 volts. That's like 1ohm on a 12 volt supply.

Just wire them all in parallel, and it's a go. It's more annoying to wire them this way rather than series, but it will work fine. I just helped a guy wire up a big array with a fixed DC supply the same way (he hates current regulted supplies more than I do), and it works perfect.

 

[purduephotog]

Watcha growin?

I have the same problem with Bridgelux. 9.8 volts at around an amp, and they suck up smaller current regulated supplies to the point it isn't practical to use them. Plus, I'm growing increasingly aggravated at Xitaniums and such for really big LED arrays because current regulation *isn't* mandatory.

We should really blame Nicola Tesla and his durn AC power for this, but I think I might have a more practical solution. I use computer power supplies for my Bridgelux because dropping 12 volts to 9.8 just requires a fat radio shack resistor, and run them in parallel. It's even easier in your case because it's 11.4 volts. That's like 1ohm on a 12 volt supply.

Just wire them all in parallel, and it's a go. It's more annoying to wire them this way rather than series, but it will work fine. I just helped a guy wire up a big array with a fixed DC supply the same way (he hates current regulted supplies more than I do), and it works perfect.

Believe it or not (most don't) Lettuce. Green Peppers. Tomatoes if I can get them to start (they're weeds in the garden from so many seeds, and I can't grow them now).

Mostly lettuce- my wife likes the 'good stuff' and I can get some rotated trays that do pretty good for growth- she gets a full bowl of lettuce mixed with some cheap greens. I figure a couple of small scattered plates should keep us good all winter.

The Bridgelux drivers really are at a bad position- you can't make them easily multiples of three- and the 16.8V one is a killer.

 

[blasterman]

Yeah, I hear you. I get an E-mail about once a week from *those* guys. 😡

Like I said, if this were my project, and were working with a lot of 11volt Vf emitters, it would be a no brainer. 12volt PSU (or any dedicated 12volt switched supply), and just run a high wattage 1-2ohm power resistor on the common +. It's that easy.

While I'd prefer to build a dedicated supply (if not for the sake of it for learning) as you've seen this approach has practical limitations. A $25 computer PSU -vs- a horde of expensive Xitaniums. Hmmm....

Yes, the Bridgelux (like a lot of other big LED arrays) have absurdly impractical Vf specs. That's why I stick to the smaller ones.