- Joined
- Jan 17, 2013
- Messages
- 27
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Hey guys,
I bought a 100mW green laser diode (no driver) from some no name company from china. The specs recommended driving it at 250mA. So I plugged it into my variable power supply, and slowly increased the voltage until the supply was delivering 250mA. It worked very well, a nice well defined green beam.
I also have an LPC 826 with a DDL driver circuit with a 25 ohm pot. I have successfully powered that circuit using a fixed power supply that I built (which has settings for 5,6,9, and 12V, which is several more volts than I'd need). The LPC 826 worked in that circuit with no problems. Then I plugged my green diode into the DDL driver and started it out at the max resistance to prevent too much current. I slowly adjusted the resistance down, but no beam ever came out.
Uh oh, I thought I pumped too much current through it and broke it.
But then I plugged the green diode back into the variable supply... and it works fine.
So I thought maybe my fixed supply was busted. I brought it to work with me, and used a high end variable power supply. I plugged the diode into my DDL circuit, and it didn't work again. So I thought my LM317 was broken. Nope, still working just fine, and yes, it has a heat sink on it. Then I decided to plug the laser straight into the high end power supply and make it deliver 250mA.
And it doesn't work....!
I bought a 100mW green laser diode (no driver) from some no name company from china. The specs recommended driving it at 250mA. So I plugged it into my variable power supply, and slowly increased the voltage until the supply was delivering 250mA. It worked very well, a nice well defined green beam.
I also have an LPC 826 with a DDL driver circuit with a 25 ohm pot. I have successfully powered that circuit using a fixed power supply that I built (which has settings for 5,6,9, and 12V, which is several more volts than I'd need). The LPC 826 worked in that circuit with no problems. Then I plugged my green diode into the DDL driver and started it out at the max resistance to prevent too much current. I slowly adjusted the resistance down, but no beam ever came out.
Uh oh, I thought I pumped too much current through it and broke it.
But then I plugged the green diode back into the variable supply... and it works fine.
So I thought maybe my fixed supply was busted. I brought it to work with me, and used a high end variable power supply. I plugged the diode into my DDL circuit, and it didn't work again. So I thought my LM317 was broken. Nope, still working just fine, and yes, it has a heat sink on it. Then I decided to plug the laser straight into the high end power supply and make it deliver 250mA.
And it doesn't work....!
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