Automation pHat output current


I want to use my Automation pHat to control a fish tank light rated at 8W 12V.

The outputs are rated at max 24v and 500mA which is 12W

My fishtank light will use 8/12 = 666mA.

My question is would this be OK as the current is higher than the docs but the overall power is less at 8W?



To be on the safe side, you could pair two of them together. As long as they are available in your particular project. I’ve not attempted switching any especially high-current loads with the darlingon driver, though, so I don’t know what you might be able to get away with.

Um ok, I will try it and see if it gets hot :)

To be fair, it does say in the datasheet:

The collector-current rating of a single Darlington pair
is 500 mA. The Darlington pairs can be paralleled for
higher current capability.

So you should be able to get away with using two in parallel. Given that your load is constant, I’d favour that over overdriving a single pair.