What type of driver does a DPSS green have?

I've been in Shanghai for a week and brought back my first green laser (supposedly 50mW, but comparing with my ~270mW red, I'd say it probably is just 15-20mW, they appear more or less similar in brightness... pity I don't have access to a LPM). Now I'm wondering, what drivers do these cheap lasers have? Most likely not a drlava type buck/boost circuit (too expensive), neither a linear driver like the LM317 (wouldn't work due to the high voltage drop). Essentially the driver is delivering an estimated 2.0-2.5V to the diode (depending on current) from a 3V power supply. Does someone have info on the circuitry used?

PS. If you're in China in the next time: the street price for a 10mW green is 40 yuan (~$5.50), don't pay more :shhh:

well they might be buck/boost. they only take 3.v input. but to be honest, i really don't know.

dr-ebert said:

PS. If you're in China in the next time: the street price for a 10mW green is 40 yuan (~$5.50), don't pay more :shhh:

Click to expand...

Thanks for the heads up

Most likely buck, but they do not boost. As the batteries die so does the output, which is not characteristic of boost drivers.

Typically it is an op-amp based regulation circuit with some help from a tiny MOSFET or two.. It will be of a type similar to one of the three schematics on this page: http://www.repairfaq.org/sam/laserdps.htm#dpsglp

theyre made to drive the IR pump diodes so they only output 2-3v. since the batt combo usually used equals 3v it could be a linear or drop voltage driver.

The link in my last post is wrong..try these


http://www.repairfaq.org/sam/glpdrv1.gif

http://www.repairfaq.org/sam/glpdrv2.gif

http://www.repairfaq.org/sam/glpdrv3.gif

That would be so cool to be able to buy green lasers at stores. Wish we had that here(some stores carry 5mw but cost $80+)