does a Tip122 have a issolated heatsink?

Hey there,

I'm trying to condense three tip 122's, from 3 individual heat sinks, to a larger heat stink with pipes and whatnot... (old xbox 360 GPU cooler). I'm trying to find a data sheet that tells me if the case is active, with no luck.

Can i attach 3 TIP122's Directly to a single heat sink, or Must I use a MICA sheet to insulate the case's from each-other?

Either way does anyone know a good tut for isolating T220 components?

Thanks in advance.

Has anyone used this?

https://www.sparkfun.com/products/9771

Not applicable for your application, that stuff is meant to stick heatsinks on with not stick onto heatsinks with... If you had looked at the data sheet at all likely the first page would have mentioned "Collector connected to tab" or it's equivalent.. If it's all right to connect all.. It usully isn't.. and even after gluing the transistor to the heatsink you'll still need a screw and insulated shoulder washer.

u need TIP122FP/TIP127FP

TIP122FP, ST

Yha, that was my best guess, after going through 5-6 datasheets, I finally found one that actually noted it, thnz.

It’s being used to drive 10M of RGB strip lights (common anode), So combining all the Collectors together is out of the question >.< ,So now how to Isolate them.

on my next trip to the store I’ll be grabbing some insulated washers, but for this project I’m not using pre-tapped holes. rather than drilling and tapping them,I have some of this tape handy and Spark fun says this tape is good for 50-psi.

In this case are you concerned with adhesion, application, or heat dissipation?

@ sonnyyu,

SOLD ! I'm SO picking up some of those

still have the current prob but thanks again for the part # :D

If you used suitable mosfets to switch the LED strips instead of TIP122s, then you wouldn't need any heatsinks.

Docedison:
Not applicable for your application, that stuff is meant to stick heatsinks on with not stick onto heatsinks with… If you had looked at the data sheet at all likely the first page would have mentioned “Collector connected to tab” or it’s equivalent… If it’s all right to connect all… It usully isn’t… and even after gluing the transistor to the heatsink you’ll still need a screw and insulated shoulder washer.

The specs for the tape say a 124 PSI “lap shear adhesion” (the equivalent of pushing across the surface of the heatsink) so you should be able to hang small children from it without a mechanical fastener. It also states a “creep adhesion” of 12 PSI at 150oC for 10 days; assuming a TO-220 transistor is about half a square inch I take that to mean that it would support a 5 lb weight for 10 days at that temperature. Pretty sticky stuff, it would seem.

that sort of tape is great,

BUT:

it has no long term mechanical strength,

its a plastic, and one part will slide wrt the other with time and heat.

used on things like CPU heat sinks its great, little mechanical stress to the parts, it lays flat most of its life,

usually the collector of BJT's and the Drain of MOSFET's is connected to the heatsink, most often these are the middle terminals. To find out if you have the actual part just do a multimeter test for continuity.

dc42: If you used suitable mosfets to switch the LED strips instead of TIP122s, then you wouldn't need any heatsinks.

LOL, the best heatsink is no heatsink. Logic level low Ron power MOSFETs are wonderful devices.

Lefty

yep, stuff like the IRL540N, IRL8113, IRFZ44N