DX 200 Module quick review

[Hemlock_Mike]

I finally got my DX 200 module today. It looks like an Olite on the mechanical part but the driver has a large resistor tacked on one side of the driver.
As received, I noticed that all fittings are loose including the important match between the pump diode and crystal assembly. This may be a do-it-yourself allignment kit.

I powered up and got 143 mW output of green at 590 mA input to the driver. After trying to allign the LD pump and "pot modding", I achieved 160 mW of green at 610 mA input current. So far, that's the best I have gotten from this module. I'm using a regulated power supply so cells aren't a problem. Turning the pot over 610 mA seems to reduce the power output.

I'll try some more adjustments but I think I hit the limits of this module..... Still not too bad for a 150 mW module for $46.

Forget pictures, you all know what a module looks like by now.

Mike

 

[Elektrotechniker]

It looks like an Olite on the mechanical part but the driver has a large resistor tacked on one side of the driver.

Maybe you could use your multimeter to measure the resistance of that big resistor, then remove it and place another one with smaller resistance. Could that help achieve more power if more current flowed in?

 

[Hemlock_Mike]

Silver--

Adding more current doesn't help power. I can easily turn up the current and it seems fo fold back. I may try adjusting the diode some more but it is still a tight fit.
For the price, I wasn't expecting a true 200 mW.

Mike

 

[styropyro]

These are the modules used in NewWish pens, that big resistor is what they are using to keep the circuit board from getting smashed down like they used to in the old NewWish pens. Now I don't have to shove a piece of paper down there every time I get a new one to keep it from having connection problems.

 

[seoguy]

Good info, Mike!

Maybe you could use your multimeter to measure the resistance of that big resistor, then remove it and place another one with smaller resistance...

Silvershot, that big resistor is only 0.33 ohms. That circuit is capable of providing over 1 Amp to the LD - it doesn't need anything smaller!

As received, I noticed that all fittings are loose including the important match between the pump diode and crystal assembly. This may be a do-it-yourself allignment kit.

Mike, it is a 3-piece screw-together modular design. The end piece holds the collimating lens. The middle piece has the expander lens glued on top of it. And that very bottom piece (the part that the driver attaches to), has both the diode and the crystal assembly (which is aligned & glued firmly in place atop the open-can diode). The diode/crystals are mounted to the base, but extend up inside the middle piece, which serves as a cover.

The 3 pieces unscrew easily, and you can examine the crystals, and even catch a glimpse of the open-can diode!

I powered up and got 143 mW output of green at 590 mA input to the driver. After trying to allign the LD pump and "pot modding", I achieved 160 mW of green at 610 mA input current.

Some of us suspect that the higher-power modules are using a 500mw 808, and that the 200mw may actually be a 100mw design that was pot-modded at the factory to over-drive the LD, in order to get the higher output.

For comparison purposes, as set by the factory, my 100mw unit draws 530ma at the driver when connected to 2xAA's.

BTW, did your LPM readings include the IR, or just green?

I'm using a regulated power supply so cells aren't a problem.

I take it on the above current #'s, you were powering the driver with the regulated supply set at 3V?

Turning the pot over 610 mA seems to reduce the power output.

You may be reaching the limits of the LD there?

Still not too bad for a 150 mW module for $46.

Agreed!

 

[Benm]

I suppose it gets dimmer over 610 ma because of wavelength shift in the pump diode - it'll produce more IR output, but also heat up to a point where its output wavelength goes down so far from 808 that it no longer matches the ss laser input range.

 

[Gryphon]

All in all its a good deal considering its a 150mW module for 46$ shipped. Can't complain about that

 

[nikokapo]

These are the modules used in NewWish pens, that big resistor is what they are using to keep the circuit board from getting smashed down like they used to in the old NewWish pens. Now I don't have to shove a piece of paper down there every time I get a new one to keep it from having connection problems.

So THAT is the reason for the big resistor!
Finally...seems logical

 

[Benm]

All in all its a good deal considering its a 150mW module for 46$ shipped. Can't complain about that

The price is low enough, but for now i'm not really convinced all of the '200 mW' marked modules will produce that 150 mW at all. Mike might have gotten a good one here, but i've also heard of these modules delivering less than 100 mW. Still not that bad a deal, but if you consider its taking 600 mA for those 100 mW, its very inefficient.

 

[Laser_Ben]

You may be reaching the limits of the LD there?

More likely, when the input power was increased, the die reached a point where it couldn't transfer heat fast enough and began to rise in temperature causing the wavelength to shift from peak absorption.