Semiconductors at 40 degrees celcius, last infinately longer than semiconductors running at 50 degrees celcius. At 60 degrees, picture a windows file copy progress bar, but instead of copying % complete, picture remaining life expectancy.
I'm making class a amplifiers in my spare time. A 2x15W class a amplifier idles (yes, IDLES) at 2-3 amperes per channel when not playing anything at all. To make ut perfectly clear, when the amplifier is ON, but NOT playing any music out to the speakers, they still draw 2-3 amperes per channel. Just by being switched ON.
As output transistors, i use Mj15003 which can handle 10 amps / 250W. when PROPERLY heatsinked. Same goes for the KBPC3510 Rectifiers. They can handle 35 amperes when heatsinked, and 10 when not. Needless to say, even when half-assed-effortly heatsinked, they reach 80-90 degrees celcius. EASY.
So, what did i do to cool them, and why do i even care?
My amplifier is a standard 42,7CM width, having heatsinks all along the sides. I bought an IKEA table, lifted the bottom shelf, basicly creating a box, sawed two slots the same width and length as the heatsinks, then put two 120mm fans at the bottom of the "box", sucking cold air in from below, and blowing the air out through the two slots underneath the heatsinks.
With this solution, i reduced the temperature of the heatsinks from around 75-80 degrees celcius to below 35! Yes, i made my class a amplifier cooler than body temperature, which is hilarious if you either know or read up a bit on class a amplifiers. :-)
So, why did i put so much effort into this?
The 2x15W class a amplifier i use, have 2x100.000uF capacitors. these cost 500 norwegian kroner each (around 90$ each)
The output transistors are genuine and cost 40 nok (around 7$) each.
Also, all the heat from the components mounted on a heatsink that transfers heat into the air, instead of trapping it inside the case, adds to reduced heating costs, instead of adding to repair/replacement costs.
Someone above argued that fans are bad because they INSTANTLY makes 8 BILLION tons of dust, magically appear inside your computer. This is just... no. Just, no.
Someone else argued that fans are bad because people usually put them in opposite ways...
No. Again.. I... no. Just... NO!
Fans don't automatically suck or blow. They do one or the other, based on where you put them and how you connect them.
There's a thing called positive air pressure, which you will get if you got 3 fans sucking cold air in, and 2 fans blowing hot air out. This does in theory prevent dust from gathering inside your computer.
What's a REAL killer though, is having your computer near the kitchen, where you fry and boil whatevere in fat and oil all day long. Good luck getting those fans clean JUST by blowing them with a spray duster...
I digress...
We live on an ever-shrinking island. Every day, there's an %&$#?@!%&$#?@!%&$#?@!%&$#?@!%&$#?@!%&$#?@!%&$#?@!, being bored and overclocking his Amiga, pushing the limits and killing another 68030/040/060 that's NEVER gonna be replaced. NEVER! When you fry it, there's ONE less left in the world. PERIOD.
In my mind, EVERY Amigan got an obligation. To take the best care of his/her hardware as he/she can, and when he/she gets bored, SELL it to someone else who would LOVE to take care of it with love, tenderness and joy.
040's get rather hot.
A rule of thumb i use with ALL semiconductors, ESPECIALLY those that are irreplaceable, if you can't touch it, HEATSINK it! Better safe than sorry!
Someone mentioned they used fans and it sounded like an airplane...
SERIOUSLY?!? What fans did you use? Heard of Papst? Heard of using a size larger fan, running at a bit lower voltage? I got like 7 fans in my Define R3 PC case, and i can't hear them at all. The 9 3TB harddrives i got in it WASTLY overwhelms the silent fans.
