Solid state relay question re heat sink size

[domwild]

Hi,

This message is on the side of a Gordos G280D45 SSR, 280VAC, 45 Amp. Input 3-32VDC. Assuming I wished to drive this relay at its max. rating, what sort of a weight in grams or size should this heatsink be??

Does this mean per watt, the temp is going to climb 1 deg. C

Thanks.

Regards,

[commanda]

12.6 KW. What mischief are you up to?

Suggest you go to jaycar.com.au and enter "heatsink" in the search box. Look through what they have available, will give you a good idea.

For instance, a fan type, 105mm wide * 225mm long, is 0.9 degC/watt.

Fan type, 105mm wide * 135mm long, is 1.1 degC/watt.

I think the flat plate formulae are in my voltage regulator book on the bookshelf at work. Google would probably find it.

Amanda

[Flux]

1 degC/Watt heatsink naturally cooled is big, the biggest thing you see on audio amplifiers and regulated power supplies is not likely to be better than this.

You can get away with less if you fan cool but that is incredibly risky as you will fry if the fan fails.

At that rating you are into an expensive finned extrusion or a monster thing if you fabricate from aluminium sheet and you will need several layers at the centre with the edges folded into fins.

Flux

[dinges]

http://www.epanorama.net/links/basics.html#cooling

[s4w2099]

If you cant find one thats big enough maybe you can build it.

http://sound.westhost.com/articles/diy-heatsink.htm

[domwild]

Thanks Amanda and others,

Will go to Jaycar and look it up. As this relay only cost AUS$10 I could not resist.

Regards,