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Topic: Tip 147 heat sink (Read 604 times) previous topic - next topic

sumanthshekar

Hello!!
In my current project i am using a 5A wiper motor driven by an arduino. I have used tip147 pnp power transistor and a 2n2222 npn transistor to make a sort of fragment of a h bridge. And it works well.. My question is, would it suffice to just add a heat sink to the tip147 or do i have to put a cooling fan also.. Btw i am using 3 motors of the same kind with same setup. And please suggest good heat sink.
Thanks in advance..

Constantin

#1
Apr 30, 2014, 10:10 pm Last Edit: Apr 30, 2014, 10:13 pm by Constantin Reason: 1
Have a look at the data sheets and determine how much heat the chip is going to have to dissipate based on your measurements (i.e. use  a DMM or similar device to determine the maximum wiper motor current). Next, see how many *C the device will heat for every watt of heat that has to be dissipated. Determine the maximum ambient temperature and the maximum temperature you want the TIP 147 to reach, now you know the allowable delta-T of heat rise. Then use a chart that the manufacturer of the TIP hopefully provides to see how big of a heat sink they recommend for a given Watt dissipation and allowable heat rise.

Googling brings up articles like this one at Digikey, this one at Sparkfun, or this one at Texas Instruments.

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