MEXICOWANDERER wrote:
GordonThree, thank you! That rule of thumb you quoted is going to help me. I am considering buying a copper CPU heatsink and mounting as many (6 max) chips on the CPU pad. I purchased some thermal adhesive but I do not know how it compares thermal transfer wise to old-fashioned zinc oxide past and drilling micro holes for #2 screws.
I also need to conjure up somewhere a micro 12 volt to 5 volt DC to DC converter for the CPU heat sink fan. Yeesh, if I end up throttling back on watt/minutes with an LED dimmer I wonder how this is going to affect the DC to DC converter. Will it throttle back as well or end up cycling.
Availability and the Oops factor inhibit full scale tinkering. Fifteen hundred mile journey to fetch packages is a bit daunting.
You need to modify your thought process a bit on getting it to 5v... I built lights for riding at night on my mountain bike out of LED"s based on LI Ion power packs and before that NiMH power packs, when money was a bigger concern than weight. The key is to get a good understanding of the Forward voltage required of the LED, and build, generally in series wiring a 3 pack of light bulbs, so that you can use 12V source as it is.
You may also need a buck or boost board, to get the voltage where you want it, and a PWM driver of sorts, to control the amperage supplied the lights.
Fish around here for ideas.Another great resource is one of the led flashlight boards, where guys mod the heck out of their flashlights, though I can not find it right now. The flash light geeks were brilliant at putting drivers, buck and boost boards, LED's, batteries, and aluminum tubes together to get a good working finished product.
Found it, sniff around here.
