Woe... I'm using ten of these and parallel. I WAS going to just use a 1 amp 5 vdc power supply with a 2.8 V zener diode to adjust the voltage to 2.2 V. I take it this is too simple.
On Fri, Aug 29, 2008 at 10:46 PM, Mike Jarabek <[EMAIL PROTECTED]> wrote: > Robert Butts wrote: > > > > Below is the link to the datasheet of a laser diode in using. It's > > not clear how I would wire this. Any suggestions on how to wire these? > > > > Digikey link: > > > http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=67-1500-ND > > > > Datasheet link: http://www.lumex.com/pdf/OED-LDP65001E.pdf > > > > <http://www.lumex.com/pdf/OED-LDP65001E.pdfTG%20keenly> > These devices usually have a laser diode and a PIN diode facing the back > facet of the main diode. The PIN diode is to sense the power output of > the main diode, and can be used in a control loop to servo it. The data > sheet shows the current through the PIN diode when the laser is > operating at 5mW, this information can be used to design a control circuit. > > The terminals you are interested in for the main diode are the ones > labled LD+ and LD-. The PIN diode is connected across the terminals > labled PD+ and PD-. (The + is probably the anode and the - is the > cathode.) > > The typical circuit to drive one of these things is a constant current > source, I have seen circuits that have an op-amp that controls a FET > with a series resistance on the ground side to measure the current, and > feed it back to be compared to a reference control voltage. If you can > get your hands on a dollar store laser pointer, you will probably find a > simple circuit with a single transistor to limit the current, this will > probably work fine but won't protect against the thing > self-destructing. Either the sense resistor or the current from the PIN > diode (or both) can be fed back to control the output power. > > You do have to be a bit careful with the voltage and current on one of > these things, if the power gets to high they run away and self > destruct. Don't exceed the operating voltage or current with your > current source. Don't hook it up backwards, as this will also wreck it. > > You will also need some optics as the beam coming out of this device > won't be colimated. Note too that the beam is quite oval shaped, 9 > degrees in the horizontal and 35 degrees in the vertical. > > Hope this helps. > > > _______________________________________________ > geda-user mailing list > [email protected] > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user >
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