Hello all,
I am new here. I have been an on and off lurker for some time now. I recently got one of these high power laser diodes on ebay:http://cgi.ebay.com/ws/eBayISAPI.dll...m=130303050585
Now, the auction says 35watts. The seller says 35watts. But these look ALOT like the youtube ones that are more like 60Watt lasers AND the seller claims they threshold at 17amps. I spoke to a few others that bought the lasers and one agrees that they are indeed the 50-60watt laser diodes that made their way onto youtube. (Cutting soup cans and unleashing general hell on most materials).
A few others claimed that they cant handle more than 17amps and one fellow claimed his died when he drove it to 25amps. My bet is that these are the super high power lasers on youtube, but that the few that complained simply dont know how to use them. Water cooling is critical for even a second. A good driver is also important, but seems less important than cooling.
So I would like to get some thoughts on these lasers. Crap? Worthwhile gamble? $150 shipped for free seems like an excelent deal for these things!
Here is how I plan to run it:
Cooling: I have one of those prowater Thermaltake CPU water cooling kits. I will use the pump and radiator to cool the laser. If these CPU coolers are not enough, I could add the included waterblock into the system and put it on a 12volt 6A peltier I ripped out of a coherent FAP module (for a 40watt diode). This ought cool the water, no? Do these things require special liquids, or could I use deionized water from the supermarket?
POWER: I built a constant current driver using three op-amps to control three 75amp mosfets. Current control is via a precision potentiometer and a precision voltage reference. Power is from a 5 volt 40amp vicor flatpac. (Voltage trimmed down to 2.8volts). I added a pi filter on the output to cut output ripple.
I will need to add another 5 volt 40amp flatpac in parallel to run this to its max, but for now will stick with 40amps.
How does all this sound?
Thanks much!
Matt