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Slothie · 24th Nov 2022, 9:41 pm

Sirius's idea is good - the heatsink outlined in the construction manual (and I have on my MK14) should be considered the bare minimum. It gets quite hot, enough to be at least uncomfortable to touch, but I measured the temperature after 10 mins or so with a thermocouple on the tab of the 7805 and it was about 55 degrees in a coolish room (22 degC) with a 7.5v input or 69 degC at 9v (wouldn't recommend more than 9v). I don't think this will cause a shortened life for the regulator, but more cooling really can't harm, and you won't risk touching something hot!

Another option is to use a switching 7805 alternative like the ones advertised on eBay but I have done no testing with these as to the reliability or how much noise they output (although with all the decoupling on the Issue VI that shouldn't be an issue).

Ideally if you're going to put it in a case, mount the regulator remotely on the case or larger heatsink.

24th Nov 2022, 9:41 pm	#26
Slothie Octode Join Date: Apr 2018 Location: Newbury, Berkshire, UK. Posts: 1,287	Re: Idiot building a MK14 thread Sirius's idea is good - the heatsink outlined in the construction manual (and I have on my MK14) should be considered the bare minimum. It gets quite hot, enough to be at least uncomfortable to touch, but I measured the temperature after 10 mins or so with a thermocouple on the tab of the 7805 and it was about 55 degrees in a coolish room (22 degC) with a 7.5v input or 69 degC at 9v (wouldn't recommend more than 9v). I don't think this will cause a shortened life for the regulator, but more cooling really can't harm, and you won't risk touching something hot! Another option is to use a switching 7805 alternative like the ones advertised on eBay but I have done no testing with these as to the reliability or how much noise they output (although with all the decoupling on the Issue VI that shouldn't be an issue). Ideally if you're going to put it in a case, mount the regulator remotely on the case or larger heatsink.