The Renard 24ss Higher channel amperage??

[griffixdc]

i haven't bought any of these yet but when the BOM hits i will do so ....but i would like to Mod a couple of the units to allow about 7 amps per channel if i need them to be....of course i understand i don't want to exceed the initial 15 amp input on both sides of the board a total of 30 amps MAX. Some of my channels will have spot lights or old C9 light strings and will pull about 5 amps of power...i am also looking into adding servo's to actuate moving displays so more than 2 amp MAX will be needed there. Any help is Much appreciated. i would like it to be as simple as replace the triac with a high capacity on the same board with maybe larger heat sink but i don't know if that is possible.

[dirknerkle]

IMO, it sounds to me like you'd almost be better off designing heavy-duty external SSRs and taking the outputs from the front ends of the MOC3023s on the SS to the SSRs. The A/C traces on the SS board are pretty healthy, but nowhere near enough to handle 7A per channel. And if you go this route, it'd almost be easier to use a Ren24LV board or a Ren64, either of which are designed for external SSRs, in place of the SS boards.

[IdunBenhad]

Hi:
I think if you try to get 30 amps through a 24 SS, it's going to be more like the 4th of July than Christmas.

[chelmuth]

Idea's for 4th Display Finale'? (SP) Lol

[dirknerkle]

LOL! It wouldn't be blinky-flashy... it'd be more like FLASH! and "Hey honey, where's the fire extinguisher?"

[james70818]

We have rules about Pyrotechnics here!

:)

[griffixdc]

so i am not understanding ...if the board is rated for 2 amp per triac with 24 channels ...but the main fuse only allows 10 or can be switched to 15 bi-fed so a total of 20 or 30 amps why cant it handle it i know in common electrical degrading you calculate a 80% deduction for power based of the protective devices or multiply by 1.20 to find what is proper to protect....why would it explode so to speak, wouldn't the fuse limit it from doing that before anything else i mean thats what fuses are for unless they weren't sized properly. what is the handicap on these boards that is stopping them from reaching their potential...not big enough heat sinks other components not rated for the extra power

[IdunBenhad]

Hi:
All the later comments were tongue-in-cheek and meant to have fun. As far as I know, there have not been any actual explosions or fire. However, 30 amps is a lot of current for any controller.

The limitation is the printed circuit runs for the triacs. This is all explained in the WIKI, which you should read.

http://www.christmasinshirley.com/wiki/index.php?title=The_Renard_SS24_Controller_Board

Maybe the designer, Wayne J will check in and give you his opinion. His design and documentation are excellent and there are a lot of them in use and there will be many more.

There is a planned group buy coming in March.

DIYCers tend to be conservative (except with money) when it comes to the controllers and associated parts. That is why DIRKNERKLE suggested it would be better to use external SSRs. He was responding to your question about how best to handle the larger currents.

Merry Christmas and Happy Blinky-Flashy

[chelmuth]

I believe it may have also been stated earlier that the biggest reason could be the traces on the board itself may not be large enough to handle the amperage..

[Wayne J]

There are many guidelines when designing a PCB. Trace width/weight AND spacing, based on voltage and current, being most important. The traces on the SS boards are in no way, shape, or form designed to handle the types of current you are discussing here. The wiki gives the guidelines on the amperage of the SS boards and this is where they need to stay. ;)
If you desire or need these high amperage ratings, maybe Frank's 24HC channel board, or a design of your own would be best suited for you. :)

[griffixdc]

ok better put ...thanks waynJ ...so what would be the maximum amperage draw i should safely use for this board and safe amperage draw max per side. I am trying to get away from having duplicate purpose channels just so i am safe with the amperage draw.

[dirknerkle]

ok better put ...thanks waynJ ...so what would be the maximum amperage draw i should safely use for this board and safe amperage draw max per side. I am trying to get away from having duplicate purpose channels just so i am safe with the amperage draw.

It's all in the Christmas Wiki, just waiting for you to read it. :p

[Wayne J]

This board would be more suited for your needs. ;)

http://store.kostyun.com/product.php?id_product=26

[P. Short]

It's a topic for further discussion, but I think that it is possible to wire up one of the SSxx outputs to an external resistor and higher-current triac to boost the output current. The reasons for not just replacing the existing triac are given in the previous posts, so I won't repeat them.

The heatsinks for this triac needs to be quite beefy. At the 1-2A level there is almost no need for a heatsink, but the requirements go up quite a bit at the 5-7A level.

This whole thing needs to be handled fairly carefully, so as to not cause fires or other problems.

[Wayne J]

It's a topic for further discussion, but I think that it is possible to wire up one of the SSxx outputs to an external resistor and higher-current triac to boost the output current. The reasons for not just replacing the existing triac are given in the previous posts, so I won't repeat them.

The heatsinks for this triac needs to be quite beefy. At the 1-2A level there is almost no need for a heatsink, but the requirements go up quite a bit at the 5-7A level.

This whole thing needs to be handled fairly carefully, so as to not cause fires or other problems.

It is easy enough to just make a board to hold the resistor and larger triac and wire to it, but why do this when the 24HC will already handle 8A as is. ;)

[griffixdc]

is there i higher capacity heat sink for the Triacs on the 24ss that we can attach to better the cooling from the OEM BOM listed for this board? Like a solid plate not individual. Better heat sink = safer to maximize the amperage per triac /etched traces

[RavingLunatic]

is there i higher capacity heat sink for the Triacs on the 24ss that we can attach to better the cooling from the OEM BOM listed for this board? Like a solid plate not individual. Better heat sink = safer to maximize the amperage per triac /etched traces

Am I missing something or are you not understanding that the SS boards are not suited for your needs? Or did you just reference the wrong board in your last post?

The Renard 24HC that you were pointed to in an earlier post is right up your ally for the requirements that you listed. Except for form/fit and some power considerations they are basically the same design.

So save yourself some aggravation (which you stated as one of your goals) and potential risk and go with the board already designed to handle your needs.

Any help is Much appreciated. i would like it to be as simple as replace the triac with a high capacity on the same board with maybe larger heat sink but i don't know if that is possible.

BTW: The BOM doesn't have a heat sink listed for the Triacs, only the voltage regulator. The best Triac heat sinks are hand-made (which goes for both boards).

[g2ktcf]

I know that Frank has 50-100 REN24HC boards in stock. We have been discussing running a coop for the parts.....