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nutz4lights

Everybody asks about max current, what about minimum?

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Funny subject line huh? Anyways, what I am referring to with "minimum current" is, I typically buy the PC line of controllers. Next year I wanted to put a controller for several (16) small trees that will only draw around 0.1A each... seems like a waste of a card that cost $150-200 right? Well, I was thinking that I could go without some of the options that come on the cards and I'm wondering how to go about doing that. for instance, the bare cards during the sale might cost $100 but then $20 for high power heatsinks, an enclosure, etc. Can I go without the $20 heatsinks if I am doing 0.1A per channel? What about if I put the card in the plastic enclosure? The card specs state "use the high power heatsinks if you put this in the plastic enclosure" but is it really necessary for 0.1A?

Ok, that is my question, how little current can you do without requiring the high power heatsinks and what kind of enclsoure does it have to go in?

Thanks!

-Louie in Melbourne

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I use the CTB16D Kit boards. That is my choice.

I purchase the larger heatsinks cause I never know where or when I might hcnage things and need the capacity. The kits come with the standard heatsink as well. I believe I read somewhere that the standard heatsinks are good to about 2 amps per channel. BUT there then you have to the concern of mounting. As the standard heatsinks are basically just a flat piece of aluminum stock with the holes punched for the mounting of the triac tabs.

Chuck

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Thanks for the replies everybody. I guess part of me wishes that LOR made higher channel cards that were very low current. I mean, the more channels you typically use, the less you are putting on each channel current wise. I don't need 8A per channel and I don't need 30A or 40A total for 16 channels.... I need 32 channels with a total of 3.2A current draw and it seems that two x $150-200 cards is a waste for that.

You would think that with the advent of LED lighting and the low power draw that it brings, that LOR would come out with two product lines. One geared towards the incandescent group and one toward the LED or low power draw group... and I'm not talking about their DC line.

-Louie

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Louie,

LOR is slated to release a 32 channel IO mother daughter board arrangement. Some had hoped it would be out by now. This thing may be just what you looking for. I am not certain, but there maybe some info on the LOR site.

I know there are posts related to the IO board in the forums.

Chuck

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The card is not so much about direct control of lights, but rather controlling daughter cards that in turn control the lights..

http://www.lightorama.com/Documents/DIO32_Man_Web.pdf

However, all the AC daughter cards are actually higher current options..

One of them is 16 channels, 8A per channel, 30A max per bank of 8...

Another one is 8 channels, 10A per channel, 30A max per bank of 4...

However, the costs on the PC series cards are incurred for safely switching the line side of the AC power more so than how much current they can control. Looking at BTA16-600-CW, they cost under $2 each in quantity 1.. Let's say you want 3 A per channel max.. A BTA06-600-CW is $1.75 each. So you are saving $4 per controller. In reality, in bulk purchases, the prices are lower, and the savings are even less...

Other potential savings in the cards come with much higher engineering costs, and you likely won't recover any cost savings by the time you make a new version of the card, and stock both versions..

One other way to look at it is that the card kit is $99.. The complete assembled unit is $250. The assembled card is $122, and the card assembled, kit is $206. So based on this, assembling the card is about $23 and assembling the rest of the controller is about $44, so depending on how you buy, there is $23 or $47 that is not going to change for a lower power version... The difference between the bare card, and the card assembled kit is $84. So the high power heat sinks, enclosure, card to enclosure mounting hardware, cord sets, and strain relief hardware totals up to $84.. Some of that is the dual inlet cords, and all the cordage that is rated for 8A on the channels, and 15A on the inlets. You could save some money by finding cheaper, lighter gauge cord sets, and only using one inlet, and the jumper that powers the left side from the right inlet cord. You could save some money with the low power heat sinks, but now mounting the card is much more difficult. The case and strain relief hardware won't change at all for lower power..

You can also look at the fact that the card and card components is only $99 to be trying to save costs out of.. Not that likely to happen... Also note that DC card at $119 isn't any cheaper when you compare with the $122 price of the card assembled price, which is the most comparable price point...

- Kevin

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-klb- wrote:

However, the costs on the PC series cards are incurred for safely switching the line side of the AC power more so than how much current they can control. Looking at BTA16-600-CW, they cost under $2 each in quantity 1.. Let's say you want 3 A per channel max.. A BTA06-600-CW is $1.75 each. So you are saving $4 per controller. In reality, in bulk purchases, the prices are lower, and the savings are even less...

Thanks for the excellent reply. I think you hit the point I was looking for with the text I saved above. I didn't know anything about the triacs and their relative cost. What your saying makes perfect sense, there really wouldn't be a savings by going to lower current, that is not what we're paying for.... and now this all makes perfect sense to me. We are paying the $120 for the card based on what the card does, not what it is rated for, so I'm not going to save money by going to a lower current card.

The other point of my post was to figure out the cheapest way to get to a packaged 16 channel card. LOR support replied to me that the heat sinks serve two purposes, sinking heat (which obviously isn't a concern for my example of tenths of mA per channel) and mounting the card. There are holes in the LOR boards that I can use to mount the card inside a housing in this example.

I'm going to try and focus on the $100 a card price and go from there. Worry about housings and cordsets (like you said, I can use low power cordsets for cheap) later.

-Louie

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