I'm trying to work out a reasonable minimum size for the heatsink. I'm using the heatsink Heinrich sourced (pic of profile below).
I plugged the dimensions into the ESP heatsink calculator, and got this:
So 400mm of it I'd get Rth(hs-ambient) of 0.6 degC/W, but that's quite a beast. 30cm gives .8 degC/W. From the Vishay data sheet I get Rth(j-c) of .83 and Rth(c-s) of .24. So that would give total of 1.7 degC/W for 400mm and 1.9 degC/W for 300mm. I plan on black-powder coating eventually, which knocks .2 off that, but worst case...
If I go for 30cm per side, then 50W would give 95 deg plus 25 ambient, or 120 degrees. Max rated temp is 150, so it's 'safe'.
Am I doing these calcs right? I'm not going to be running the amp at full bast most of the time... so it should be mostly way within heat spec.
I plugged the dimensions into the ESP heatsink calculator, and got this:
So 400mm of it I'd get Rth(hs-ambient) of 0.6 degC/W, but that's quite a beast. 30cm gives .8 degC/W. From the Vishay data sheet I get Rth(j-c) of .83 and Rth(c-s) of .24. So that would give total of 1.7 degC/W for 400mm and 1.9 degC/W for 300mm. I plan on black-powder coating eventually, which knocks .2 off that, but worst case...
If I go for 30cm per side, then 50W would give 95 deg plus 25 ambient, or 120 degrees. Max rated temp is 150, so it's 'safe'.
Am I doing these calcs right? I'm not going to be running the amp at full bast most of the time... so it should be mostly way within heat spec.
