Heatsink; other questions

I have several old computer heatsinks,two of which are quite large, and one of which exempt from the following question(the radial one);

Would any of these be decent in a project box styled laser, or do any of you have experience using these types of heatsinks? Just wondering which you think would provide the best cooling.
-PHR diode at ~100mA
-DDL driver(12 ohm resistor, no pot)

Obviously I can cut them down if needed, even the large, non-radial heatsink, possibly even to make one for the LM317.

Re: Heatsink

the bottom right heatsink would be the best for cooling a laser as it is large and has lots of fins to dissipate the heat quicky...

stuart

Radioshack didn't have any 12 ohm resistors, for now I bought a pack of 10 ohm ones, but if I can find 12 ohm online somewhere cheap it would be preferable, anyone have any ideas on where to get some?

a 10 ohm resistor would give you 125mA which is still okay for a phr diode but pushing it a little.

a quick search on ebay and i found 12 ohm resistors : 100 x Resistors 12 Ohm 1/4W 5% Carbon Film - eBay (item 350321016921 end time Aug-23-10 00:29:39 PDT)

stuart

Oh, wow nice. Thanks for that.

I see those are 1/4watt resistors, is that okay for this application? I seem to recall someone saying to use a higher wattage resistor if you are not going to use a potentiometer.

Edit: I ended up ordering some 1/2watt ones instead, not primarily because of the higher wattage, but because the 1/4watt ones were being shipped from Bangkok :huh:

okay no worries mate

stuart

Thanks to the uber quick shipping over at Hightechdealz(two day delivery, no foolin, very pleased), I now have my phr diode in module; just waiting on the resistors now.

I've been playing around with schematics; trying to come up with a veroboard layout for my driver. So far I have come up with this, can anyone see anything wrong with it?