JSR-03, 05 Heatsinking Requirements?

[TerryC]

I finally got my first JSR-03 module assembled and working  :-D.  My initial test used a 1K load resitor (at 14.1v), so the total output current draw was ~14ma.  Before I test the circuit further, I would like to know what the component heatsinking requirements are at 100mA, 250mA, 500mA, and 1A.  The input voltage used in the final installation will likely be 22-24v, so the voltage dropped across the 317 regulator will be around 6.5-8.5 volts.

[peranders]

The D44H11 will get 2.5 volts between collector and emitter, from this you will get:

100 mA => 0.25W
250 mA => 0.625 W
1 A => 2.5 W
1 W is the limit without heatsink.

20 deg C/W will get the heatsink 20 deg C warmer for each watts.
5 deg C/W will get the heatsink 5 deg C warmer for each watts.

The voltage across the LM317 will be Vin-Vout-2.5
1 W is the limit also here.

If you have a flat surface you can use this a heatsink.

Some inspiration here:
http://bergrans.despinnerij.nl/index.php?content=power-supply

You'll have to calculate how much voltage drop you'll get at the current you'll have.

If you'll check the picture of JSR06, this heatsink will manage 250 mA out at 14 volts and 19 VDC in.

[TerryC]

That's very helpful.  Thanks.  I'm not expecting to draw more than 200mA, but I will definately use a minimum amount of heatsinking.  I probably should have figured this out before I stuffed the board.

I like how Bergrans has implemented heatsinking.  Any idea what kind of material is being used?  It's a much cleaner solution than using off-the-shelf heatsinks on each device.

[peranders]

They are made of massive aluminium, black anodized.