How many amps per channel and is a heatsink needed?

[jwilliams31]

I've been going through the different posts and I see some that say that the SSR4 can do 1 amp per channel and 2 with a heatsink.  Then I've seen posts that say they can do 2 amps without a heatsink.

So my question is do I need to add a heatsink to run 2 amps per channel.

Also, just for clarification, 1 amp is about 300 mini-lights, correct?

Thanks.

Jason

[aERonAUtical96]

The rule of thumb I've used is 1 amp/channel=no heatsink, 2 amps/channel=heatsink.

While you probably can get aways w/o putting a heatsink on for 2 amps, why not just do it to be safe.  I would think that if someone is hitting 2+ amps / channel w/o a heatsink, then they might not be doing it on a high load (continuous) basis, ie hit that channel once every 20-30 seconds vs all on all the time (hope that makes sense).

You really need to look at the amperage of the string.  I have 100 count, "energy efficient" strings that are .20/.24 amps vs .33-4.  So I can get 4 / channel.  Take a look at the string on the safety sticker and it should tell you what the amperage is.

[dmaccole]

The BTA06-600SRG that RJ calls for in the SSR4 BOM are six-amp, 600-volt TRIACs, which would mean that you could run up to three amps through them without a heat sink.

You probably don't want to run more than three amps through them regardless, as I believe the copper traces aren't rated any better than that.

So a heat sink is not necessary.

And you probably should always measure your light strings to determine their draw, rather than relying upon rule-of-thumb or even packaging claims. The Kill-a-Watts are running $15-$17 these days on-line (w/o shipping) and well worth the investment.

\dmc

[jwilliams31]

Thanks for the info.  I would prefer not to put too much load on them, it's just that this year I have more lights than channels so I wanted to see how much I can get on there so I can at least have all of my lights controlled.

[RJ]

They are not rated for three amps without a heat sink.

To220 packages can only handle so much with out a heatsink. They do not have enough area to move more heat so a to220 triac rated at 3 amps and one rated at 8 amps still is limited by its package to roughly the same current limit. To handle the higher currents requires a better heatsink. The difference is the 3 amp can not handle higher no matter what heat sink you put on it and the 8 can.

Run them at 1 amp without heatsink and while they will most likely survive 2amps with out I would recommend if you want that much current running a heatsink.

If you do use the thinest aluminum angle you can find. Too thick will run the wires and thickness is not what cools the triac it is the area so big area thin is what you want.

RJ

[rrowan]

Hi RJ,

How about a small piece of the tile from the shuttle.

that should help remove the heat

Yes I am just kidding

Rick R.

[RJ]

Hi RJ,

How about a small piece of the tile from the shuttle.

that should help remove the heat

Yes I am just kidding

Rick R.

No No No Rick that is an insulator it would not get rid of the heat but hold it in. LOL
RJ

[dmaccole]

They are not rated for three amps without a heat sink.

I misunderstood. Sorry for posting incorrect info.

\dmc

[jwilliams31]

I bought the aluminum last night.  Either way, I figured it couldn't hurt to add it.

I'll have to look into a load tester, just to be safe.

Thanks.

[WWNF911]

Hey RJ,

I'm planning on running some regular C9's for the roofline this year. (couldn't find any red or green LEDS so just bought regular. Hopefully next year) Have you tested anything like these on the SSR4? I'm thinking somewhere around 1.8 AMPs per string/channel and was planning on preparing some heatsinks. Wonder if anyone has a template I can use for measuring/ drilling the necessary holes? Just curious. Any suggestions on where you found the aluminum angle and what size? I'm thinking HD or ACE and probably .5 inch? 

Leon

[WWNF911]

Bump.

                                     /\
RJ?                                 |


EDIT - Think I found answer in Post #4. Thanks

[RJ]

Sorry it got missed. I do not have one and sine the triacs could be solder a little one way or the other you almost have to measure or create the heatsink before you attach them and mount the triacs to it before you install them.

HD or Lowes should have some thin aluminum angle theat will work and with not a lot of it attached 1.8 amps per channel will be fine. I would not leave it on continuously for an hour but if it is off any once in a while it will not get too hot in the case. (very Warm yes).

RJ

[memphislights]

I saw some thin aluminum outside corner bead for drywall at Home Depot or Lowes.  It is about 1"x1"x8' and really thin.  It was also really cheap at like $2 for an 8' piece.