silicon controll rectifier (SCR) or solid state relay (SSR)

[Tony]

Those heatsinks would probably work up to about 20 to 30 amps, difficult to be precise, but are far too small for the required 70 amps you mentioned in your first post. Even with a cooling fan it would be marginal.

If you cannot comfortably hold your finger continuously on the heatsink at full power without screaming, the heat sink is becoming far too hot.

A flat plate 12 inches by 12 inches or a total fin area of 150 square inches would be minimum.

[Brucepts]

The first heat sink is to small for anything over 40A, the second one is what is available now for the 40A+ SSR's as you can see they are not inexpensive.

Trust me I've researched this to death or I would not be selling them

[watercooler]

Ok so I finally came to the conclusion rather than spending a arm and a leg on a piece of aluminum thats adequate to dissipate the heat I came across this,Its very big and only need miner modification as to mounting it on a flat surface I shall use aluminum L brackets take a look.
http://www.ebay.com/itm/Aluminum-Large- ... 3a7841ef5d
and for the L brackets I have some 1/8" around my house but I am posting this as a reference.
http://www.ebay.com/itm/1-1-2-x-1-1-2-x ... 27c7e84ebb

Bruce I also found 2 HE-90 which is the equivalent to 90 amps heat sinks for you,they are pretty cheap and the buyer said its old stock.
http://www.ebay.com/itm/230480293439?ss ... 1438.l2649

[Tony]

That is much better.

[yosemitedale]

Hi, Watercolor, and everyone,
Hey, Watercolor, Did you get your get your new motor control setup working yet, and how much did you spend on it?
Haven't decided what I'm going to do yet with a motor control.
Is Bruce's setup that he sells, still the easiest and cheapest way to go?

Thanks, everyone

[bstryk]

If I may jump in several months late...

I've just purchased the Crydon SSR with ECD board for a temp control application, but after an exhaustive multi-day search for a data sheet on the board, I've come up empty handed. I am looking for power, terminal/pin and jumper information to get this thing powered up and running. Watercooler, did you have any success getting the board working? Do you have any insight you can share on setup?

[Tony]

Try searching Crydom not Crydon

[01z28auto]

Hey guys,did any of you figure out the crydom with the ecd board?