DX200 red orig.driver mod to 200mW+ w/ 3.0V CR2

[icah93]

Hello.
Today I tried to modify the original driver to achieve 200mW+ with 3.0V CR2s. There is a big resistor as 6.2 (6.2 Ohm) on the driver. I have added a 10 Ohm/0.6W resistor parallel to it and voila, the original 235mA raised to 268mA stable, when using 7.1V total. No more current can be achieved by modifying the measure of that resistor, the next step would be to add a resistor parallel to both 6.2 res. + pot. I am awaiting a bit more current for the LD this way.

If anyone has any idea what else can be modified to achieve at least 300mA/7V feel free to join the topic.

 

[Benm]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

It wouldnt be much of a problem to construct a 700 mA driver from scratch that fits the available space... and that would also allow the current to be more independent of battery voltage - at least allowing nearly the same power output regardless of using 3.0 or 3.6 volt cells.

I'm not very fond of the dx200 driver as it is mainly because it does little in actually regulating the diode current. Bumping it to 300 mA by whatever means does seem a bit on the edge - i know the diode survived this for many people but i still wonder for how long

 

[icah93]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

I am talking about 300mA for the LD only because I have read that in the other's posts and I assume it can be close to the advertised 210mW output power. I have ordered mine from the UK not from DX but it is visually the same circuit and it came with the warranty of being able to produce output of 210mW (measured by them). Knowing this and the fact that I measured 235mA draw from the 7.1V total batt indicates that something smells over here. Either the output is lower or the circuit is different... I am not sure as I do not have a laser power meter.

BUT! 1 thing is sure: I have measured 300mA@8V, constant stable current on the circuit.

 

[icah93]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

What about to get out the 6V protection diode, this could get 0.7V more...

Should it be simple desoldered or should both sides get connected afterwards?

 

[Benm]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

If it is just a diode in series with the battery, you can bridge it with a wire (shorting one end to the other). There is no need to remove it, altough you obviously can if you want.

 

[lasersbee]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

What about to get out the 6V protection diode, this could get 0.7V more...

Should it be simple desoldered or should both sides get connected afterwards?

You can use 3.6Volt CR2 batteries instead of the 3.0Volt CR2s..... :

Jerry

 

[Benm]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

You can to increase power.. exactly something a proper driver would solve

 

[icah93]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

[quote author=icah93 link=1233834330/0#3 date=1233855545]What about to get out the 6V protection diode, this could get 0.7V more...

Should it be simple desoldered or should both sides get connected afterwards?

You can use 3.6Volt CR2 batteries instead of the 3.0Volt CR2s..... :

Jerry[/quote]

Sure, I have already ordered 2 pcs, but still I would like to find a workaround so the many other users do not have to change the driver anymore and even with 3.6V batts the output power may get increased by modding the driver...

 

[icah93]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

If it is just a diode in series with the battery, you can bridge it with a wire (shorting one end to the other). There is no need to remove it, altough you obviously can if you want.

THX, will try it and let you know the result, maybe with this and the 10 Ohm resistor already soldered there
I can reach the magic 300mA
I would not go for that current if I knew that I already had the promised 210mW output.

 

[Benm]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

I will help a little bit - dont expect a major increase in current or power, but it could be enough for you.

I'd be careful pushing things, the dilda is a nice host but its themal transfer is limited by the small size - running it at 300 mA will make the diode run warm, mostly resulting in longer wavelength and a drop in visible power (burning will do fine as long as the diode lives however).

 

[icah93]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

I will help a little bit - dont expect a major increase in current or power, but it could be enough for you.

I'd be careful pushing things, the dilda is a nice host but its themal transfer is limited by the small size - running it at 300 mA will make the diode run warm, mostly resulting in longer wavelength and a drop in visible power (burning will do fine as long as the diode lives however).

As I promised, here it is. After bridging the diode (voltage drop on it is only about 0.5V) the stable current is 275mA (@6.66V total), because the initial 7.1V total drops to 6.6V in about 1 minute Otherwise it would be the nice 300mA/7.1V! If one would tell what is the output optical power at this rating I would be very grateful for it. I repeat I do not want to push the current to 300mA if not neccessary, just do not know what current can make the promised 210mW output with standard rechargeable batteries.

 

[andrelcg]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

[quote author=Benm link=1233834330/0#9 date=1233969280]I will help a little bit - dont expect a major increase in current or power, but it could be enough for you.

I'd be careful pushing things, the dilda is a nice host but its themal transfer is limited by the small size - running it at 300 mA will make the diode run warm, mostly resulting in longer wavelength and a drop in visible power (burning will do fine as long as the diode lives however).

As I promised, here it is. After bridging the diode (voltage drop on it is only about 0.5V) the stable current is 275mA (@6.66V total), because the initial 7.1V total drops to 6.6V in about 1 minute   Otherwise it would be the nice 300mA/7.1V! If one would tell what is the output optical power at this rating I would be very grateful for it. I repeat I do not want to push the current to 300mA if not neccessary, just do not know what current can make the promised 210mW output with standard rechargeable batteries.[/quote]



This measurements was on circuit driver? Correct?


Can you post some pictures for us?

Hug,
Andre Garcia

 

[Benm]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

The exact power versus current is different for each one, but i think 275 mA should put you in the 160-170 mW range - perhaps a bit over if you got a good one.

 

[andrelcg]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

One question!

What is more dangerous for the laser diode? Overload or overheating?

Hug,
Andre

 

[icah93]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

The exact power versus current is different for each one, but i think 275 mA should put you in the 160-170 mW range - perhaps a bit over if you got a good one.

I am sad to hear that. You may be close as mine diode is even not heating up so much after a few minutes.

How would I compare the optical output to others', can not I say okay some guy says he has 200mW and can light matches from 4 feet, so if I can light them also from 4 feet I have similar output? (I can light them in a few seconds from 6 feet now.)
Or maybe one could fire his 200mW(any) certified laser lets say from 1 foot to a red LED and measure the max. micro/mili/V via multimeter. This way I could compare the power of mine to his.

@Andre: Yes, all is measured on the original driver. I will upload some pics this afternoon when I am back home.

 

[icah93]

Re: DX200 red orig.driver mod to 200mW+ w/ 3.0V CR

Here are the pics.