BIP 373 Heat sink requirement

[TurboVic1]

Hi guys, i have not posted for a while, but i have been working on developing a case that will house the microsquirt module and then connect directly to my stock wiring harness on my motorcycle. I am also designing a daughter board that i will use to map the pins on the module to the pins on the receptacle that mates to the motorcycle harness.

I want to include on the daughter board (i think thats what it would be called), two BIP 373's and the 330 ohm resistors (SMT). My question is regarding the heat sinking requirements of the 373. will a cheap sink like this work:

http://www.digikey.com/product-detail/e ... 15-ND/5849? Or do i need something with a lower thermal resistance? It looks like the BIP 373's are packaged TO-220 so there are of course lots of options!

remember these will be inside a case so will be getting no airflow. Thoughts?

Thanks

[dontz125]

That's pretty much what the OEMs use on the stock TCIs, which are also closed plastic units with little airflow. Bear in mind that the BIPs run pretty cool if you don't over dwell your coils. Someone who has built many such units explained to me that the wiring harness itself will draw out a great deal of heat, so don't skimp on either the ground plane copper or the ground wire gauge.

Note that the ignition signal already has a 100 Ohm resistor in series, so you want a 220 or 230 second base resistor going to your drivers.

As for the mother board / daughter card terminology ... The module is a weird beast, having most of the necessary equipment on itself. The thing that it mounts on to connect to the outside world is more of a carrier board.

[TurboVic1]

awesome. Thanks!