New FOCUSABLE 200mW Red on DX

[IgorT]

Yeah, i meant with the laser.. Charge batteries, power up, write down current.
Use laser for some time and write down the current again. And then again.. Measure the current by replacing the tailcap with your DMM in the 20A (or highest) range...

Then turn the pot counter clock wise JUST A LITTLE, put laser back together and measure the current again, by replacing the tailcap with the DMM.


Let me know what you find, so we can figure it out.

 

[GamerBR]

Yeah, i meant with the laser.. Charge batteries, power up, write down current.
Use laser for some time and write down the current again. And then again.. Measure the current by replacing the tailcap with your DMM in the 20A (or highest) range...

Then turn the pot counter clock wise JUST A LITTLE, put laser back together and measure the current again, by replacing the tailcap with the DMM.


Let me know what you find, so we can figure it out.

I decided to just add some resistance to the connections to drop the voltage instead of waiting it to discharge,and indeed the current is dropping with the voltage.
And changing the pot and measuring current I have already done before as I said in my last posts :-?
I don't know if it's worthing opening a ticket on DX to change it.

 

[IgorT]

I know you have changed the pot already, but it would help me determine what is going on, if you had two sets of measurements..

I think your laser is below the minimum voltage for regulation, just like mine was.. In this case, you would have to use two 3.6V CR2s.. Then it actually would regulate to the current the pot sets, and it would have the same power every time you turn it on, until the batteries were almost empty.

But since you were already turning the pot, you don't know what current it is set to. You would have to lower it first (CW) and then slowly raise the current while measuring (powered by two 3.6V CR2s)...


Or, i could measure the resistance of mine, and you could set it to the same resistance, and get the same current (with 3.6V CR2s). This would be less exact, but should still work.


3.6V CR2s can't be bought at DX, but i have a bunch of them.. I could include them, and the same charger you'll need for the 14500 Li-Ion for the Blu Ray would work for them as well. You would need to use some spacers tho. People usually use the DX magnets for this.

 

[GamerBR]

I know you have changed the pot already, but it would help me determine what is going on, if you had two sets of measurements..

I think your laser is below the minimum voltage for regulation, just like mine was.. In this case, you would have to use two 3.6V CR2s.. Then it actually would regulate to the current the pot sets, and it would have the same power every time you turn it on, until the batteries were almost empty.

But since you were already turning the pot, you don't know what current it is set to. You would have to lower it first (CW) and then slowly raise the current while measuring (powered by two 3.6V CR2s)...


Or, i could measure the resistance of mine, and you could set it to the same resistance, and get the same current (with 3.6V CR2s). This would be less exact, but should still work.


3.6V CR2s can't be bought at DX, but i have a bunch of them.. I could include them, and the same charger you'll need for the 14500 Li-Ion for the Blu Ray would work for them as well. You would need to use some spacers tho. People usually use the DX magnets for this.

In the moment I'm using 3v CR2 batteries,I think 3,6v is not needed.But I can with other batteries make the same voltage as two 2 3.6v CR2's,not an issue.
I decided,as you said,to make measurents of current in a big number of voltages(all measured while the circuit was closed)
5.05v-212ma
6.19-280ma
7.34-355ma
In the 7.34 I decided trying changing the pot,and it did work fine,but lower voltages still makes the current drop.Then I tried changing the pot with two cr2's at 6.32(closed-circuit),the pot is actually working,I just didn't notice it before because the only currents I'm able to control with it at this voltage is from 0~20ma and 280~308ma,it won't go beyond,and I can't get between 20 and 280ma.

 

[IgorT]

Well, it's exactly what i expected.. The pot would only appear not to work, because the driver is not getting enough voltage on top of what the diode needs, to regulate the current..

When in regulation, the current changes with turning the pot, because the driver actually has enough voltage on top to do it's work..

You have the exact same problem i had. These drivers are made with components, that are not meant to work from such low voltages. So if it works or not, depends on small variances in the components.

You do need two 3.6V CR2s, and then set the current to 330mA, 340 max, if you want it to live for a while. If you need them, just let me know. I have a bunch of them, and could throw some in with your order.


Please be careful tho, because when the driver is in regulation, you could actually set the current too high and kill the diode.

 

[GamerBR]

Well, it's exactly what i expected.. The pot would only appear not to work, because the driver is not getting enough voltage on top of what the diode needs, to regulate the current..

When in regulation, the current changes with turning the pot, because the driver actually has enough voltage on top to do it's work..

You have the exact same problem i had. These drivers are made with components, that are not meant to work from such low voltages. So if it works or not, depends on small variances in the components.

You do need two 3.6V CR2s, and then set the current to 330mA, 340 max, if you want it to live for a while. If you need them, just let me know. I have a bunch of them, and could throw some in with your order.


Please be careful tho, because when the driver is in regulation, you could actually set the current too high and kill the diode.

I appreciate your help I have e-mailed you about the batteries ;D

 

[04orgZx6r]

I tried to find the answer but could not soi'll ask.

Is there any notable differences between the first ones shipped out and the ones shipping out with the lanyard, besides the lanyard of course

 

[FrancoRob]

I tried to find the answer but could not soi'll ask.

Is there any notable differences between the first ones shipped out and the ones shipping out with the lanyard, besides the lanyard of course

I just have received it to-day: from the exterior point of view, no differences (see annexed picture). As it arrived without batteries, shipped in a different package, I can't do any practical test for now.

 

[EchoDelta]

I tried to find the answer but could not soi'll ask.

Is there any notable differences between the first ones shipped out and the ones shipping out with the lanyard, besides the lanyard of course

Sorry for the VERY late reply.

Yes. There are some differences between what I will call generations 1 and 2 as I own both models.

Gen 1: No lanyard, Smaller output orfice, AixiZ glass lense assembly (3 element glass lense in a threaded brass carrier),
Loose or wobbley focus head.

Gen 2: Lanyard, Larger output orfice, Threaded plastic lense carrier which is shorter than the brass one that comes in Gen 1.
Also, I do not know if the lense itself is glass or acrylic or how many elements it is comprised of. The focus head is not wobbley.

The focusing head issues are directly related to the two different lense carrier materials (brass vs plastic).

Both of the units that I own perform the same. VERY WELL.

When using the 3.0v green rechargeables, Gen1 was drawing 240mA until I turned the pot. It now draws 310mA.
I did not mess with with the pot on Gen 2 as it was drawing 310mA out of the box.

I am VERY pleased with both units. The mW per dollar ratio simply cannot be beat.

I hope I have answered the questions you have asked.

Eddie

 

[EchoDelta]

I forgot to add that the rechargables are the only way to go for sheer power.

I could not for the life of me light red matches with the Panasonic primaries.

With the UltraFire greenies, They light up right-away!

Eddie

 

[LikeitBright]

I wonder why the manufacturer specifies 3.0 V CR2 if some Dx200 don't regulate with them. They must have noticed. It would have made more sense for them to specify 3.6V and then tune the pot themselves..? A bit like with the leadlight 105s.

 

[CHP]

Here is the back of the circuit board, I can take more pictures if you need them, the circuit board is easily accessible.

Has anyone traced the schematic for the DX200 yet?

I don't have one but I looks like the 6.2 ohm resistor and the 220uF capacitor form a low pass filter to minimize power transients. However, if the laser is drawing 300mA, there is a 1.86 volt drop across the 6.2 ohm resistor which may drop the circuit board's voltage below the minimum needed for proper regulation. Has anyone tried to add twice the capacitance and half the resistance to get the same filtering but less voltage drop and higher circuit board voltage to keep the laser in current regulation longer with lower battery voltage?

 

[ixfd64]

Hmm, some reviewers who claimed to have purchased the laser recently are still saying that the focusable head is wobbly. Is DX still shipping first-generation lasers along with the second-generation ones?

Some reviews also claimed that the laser heats up very fast due to the lack of a heat sink. Is this the case for the second-generation version as well?

 

[styropyro]

Some reviews also claimed that the laser heats up very fast due to the lack of a heat sink. Is this the case for the second-generation version as well?

I think most of the heat is actually coming from the driver board, not the laser diode itself! I would imagine both generations would heat up the same. Mine sure does, and I think mine is second generation.

 

[ixfd64]

Some reviewers are also saying that the lens is wobbly. Do they mean the same thing as the focusable head? If so, this problem should not be present in the second-generation model. Otherwise, this could be somewhat dangerous.

I know this laser has variable specs due to it being focusable, but what are the best specs it can achieve, in terms of divergence and beam diameter?

I'm sorry for asking so many questions, but I'm considering getting this laser some time in the future.

 

[styropyro]

By lens they meant focusing head. I never had a problem with the head being wobbly, but I could have just gotten lucky. Nearly everybody who has had that problem fixed it with teflon tape.

You can get the divergence down pretty well, maybe around .4mRad? Beam diameter is pretty big but typical of our diode lasers, I can't give you an exact measurement though.