dx true 5

[Greendream]

@Greendream:
I used to be heavy into photography, and have been looking for a nice point-and-shoot with full manual mode ability, and excellent macro capability a must. I was thinking about the Canon A590IS, until they got a good review in Consumer Reports, and price/availability went nuts as a result! Thinking about perhaps one of the older A series? Any suggestions?

I don't really keep in touch with p&s cameras, but you usually can't go to far wrong if you stick to the big camera makers like Canon, and look for the features you would like.

This site has some great tools for comparing cameras/features (check under the "buying guide" tab) and would be my first stop if I were looking for a p&s:
Digital Camera Reviews and News: Digital Photography Review: Forums, Glossary, FAQ

For macro capability, check the "close focus distance" (or "macro focus range" as some call it) for the cameras you are interested in, and find one that has a small number. 1cm should get you all the magnification you need.

Good deals can be picked up second hand from ebay if you want to save some money. Even an old 3mp can still stake good shots if it has been reasonably well looked after.

Rotated, or tilted? These lower-power modules, the diodes appear to just be pressed-in to a hole on the back. Look at the back side of the module closely - does it appear that the diode was pressed-in at an odd angle?

Tilted, which would mean than most of the output is probably not even directed at the crystal I presume.

I'm working-up something on that for you - but it's very complicated!

Much appreciated, thanks!

Actually, it does! The vandate crystal is very polarization-dependent - having the polarity of the laser lined-up with the preferred direction on the vandate crystal can more than double the output power!

I had a feeling you were going to say something like that. Thanks for setting me straight.

In fact, I finally managed to get my True 5 apart (Woo-hoo! - more on that below), and noticed that none of the sides of the crystal even line-up with the axis of the laser die - I suspect this may be at least part of the reason for the low output on this guy!

Well done

OK, let us know how that goes! :yh:

I still haven't had a chance because I've been so busy, but I'll try soon...

I guess I wasn't as clear as I could be there - what I meant was that if you were over-driving the diode, it could cause it to heat-up to the point that it would shift the wavelength away from 808nm, thus causing a drop in 532nm output.

That was a sign that you were pushing the diode too far at 344ma.

I'm with you now.

It's odd that the performance of those two were so different. Looking at the diodes front up-close through the hole, and also the back, do both diodes look identical?

As far as I can tell, yes. See below...

On your pics - pen #3 (on the left in your first pic) is what the crystals in my high-power module look like! (That's odd, I figured the 176ma one would have the different crystals, but if I am reading your post correctly, it and one of the 200ma ones share the same crystals! Is that massive difference just alignment, or are they using two different diodes??? )

Alignment and differences in the crystals would be my guess... but without measuring some more diode outputs we won't know for sure I suppose.

Yes, if could you get close-ups of just the face on the two crystals in focus at the max capability of your macro? If possible, with some object in both pics or other method to use for scale?

The reason is I am trying to identify the specific model crystals being used in these things!

BTW, the quality & efficiency of the crystals have a HUGE impact on the amount of green you can get! (For example, with some crystals, 1W-2W of 808 will only get you 50mw of green!)

Thanks! :thanks:

No problem. I had a go shooting at 5x magnification, and managed to screw up the focusing in at least one of the shots. I'll give it another go perhaps if I get a chance over the next few days, but here's what I got so far.


I found a bit of decorative ribon for wraping presents that had strips of what looks like mylar woven into it, that could be used to measure the crystal. Here is the piece I used photographed on a precise scale (~1cm across from edge to edge of frame - small divisions are 0.5mm)

Crop from the above shot:

Here's pen 3

I got a better shot of pen 1 although the strip of mylar is a bit tilted by the looks of it, so not good for taking any measurements

Here are more shots looking into the diode chamber:
Pen 1

Pen 3

From a slightly different angle:

When I get these apart I'll be able to get better shots as well as test the output of the PD

 

[roddenberry]

Damn! Awesome photos! :thanks: great macro shots of the structure of the module! You can even see the edges of the vanadate crystal and how jagged they are... What's the mW power of that particular unit you photographed?

Robert

 

[Greendream]

Thanks Robert.

Both pens in the last set of pics were putting out about 20mw when I got them. After the mods pen 1 was 62mW inc. IR @ 304mA and pen 3 was 26mW inc. IR @ 314mA

 

[milantheone]

another weird experience with my units..

i am unable to get STABLE increase in output..

all i get is fantastic brightness, but only for a few seconds, after that it starts dim.

3 units with a same problem..

I was thinking that it could be a problem with an overgeating because i drive them with more current after pot moding, so after an overheating it start decreasing an output..

so i have tried to drive them with my socket power supply which gives 4,5V and 300mah..

i turn the potentiometer to the position like comes from the manufacturer so it was supposed to be 5-10mw..
with those 4,5V i get stable output with minimum heating after a minute or so and i would estimate by E-lpm at 50mw..

What does it mean??
i cant explain it to myself..
why 3,2 V fresh voltage from my batteries is not enough to drive those units?

Thanx

Milan

 

[bryce007]

another weird experience with my units..

i am unable to get STABLE increase in output..

all i get is fantastic brightness, but only for a few seconds, after that it starts dim.

3 units with a same problem..

I was thinking that it could be a problem with an overgeating because i drive them with more current after pot moding, so after an overheating it start decreasing an output..

so i have tried to drive them with my socket power supply which gives 4,5V and 300mah..

i turn the potentiometer to the position like comes from the manufacturer so it was supposed to be 5-10mw..
with those 4,5V i get stable output with minimum heating after a minute or so and i would estimate by E-lpm at 50mw..

What does it mean??
i cant explain it to myself..
why 3,2 V fresh voltage from my batteries is not enough to drive those units?

Thanx

Milan

None of the three will power on with 3.2V?

 

[milantheone]

None of the three will power on with 3.2V?

yes all three units with a same problem..

of course they works with 2x AAA - 3,2volts, but only for a very veak otput max 10mw by my estimation..

Then after i turn the pot to get a better results, 3,2volts is not enough because it starts dim after 3-5 seconds from amazing beam to maybe 5mw.. I was thinking it is overheating, but it is definitelly not..
With more volts - no dimming and stable powerfull output..

Milan

 

[bryce007]

yes all three units with a same problem..

of course they works with 2x AAA - 3,2volts, but only for a very veak otput max 10mw by my estimation..

Then after i turn the pot to get a better results, 3,2volts is not enough because it starts dim after 3-5 seconds from amazing beam to maybe 5mw.. I was thinking it is overheating, but it is definitelly not..
With more volts - no dimming and stable powerfull output..

Milan

Did you measure the current using different voltages? Is it staying constant? I have three true 5's here, and one has a defective driver, meaning the current changes when the voltage changes. But the other two keep a constant current.

 

[Shogoki]

another weird experience with my units..

i am unable to get STABLE increase in output..

all i get is fantastic brightness, but only for a few seconds, after that it starts dim.

3 units with a same problem..

I was thinking that it could be a problem with an overgeating because i drive them with more current after pot moding, so after an overheating it start decreasing an output..

i get the same exact thing... and i'm thinking the driver is messed up like bryce mentioned..

it's not keeping a steady current with changes in voltage..

what's more weird, is that my output WILL be stable.. as long as the laser is open without the bottom piece screwed in.. and the ampmeter is in place as i'm measuring the current.. with the leads on the positive of the battery, and the other lead on the case.

if i screw everything back together.. is when i get that symptom. don't think it's an overheating issue... more guessing something else.

 

[milantheone]

Did you measure the current using different voltages? Is it staying constant? I have three true 5's here, and one has a defective driver, meaning the current changes when the voltage changes. But the other two keep a constant current.

i am unable to measure the current.. i dont know why, but i simply cant.. i have mentioned it couple of times in this thread..

shitty

 

[bryce007]

i am unable to measure the current.. i dont know why, but i simply cant.. i have mentioned it couple of times in this thread..

shitty

Blown fuse in your DMM?

 

[milantheone]

Blown fuse in your DMM?

no, i have got digital multimeter, witch automatic range..
one i was able to measure the current on my not pot moded laser.. it show me around 170ma

but after pot moding i am unable to check it.. multimeter just go UP and DOWN without showing any NORMAL drawing.
it seems that i am unable to check everything above 200ma..
i really dont know..

also i was pointet to change my batteries, but it didnt help.

i have got this piece of s... equipment.
DealExtreme: $10.40 Auto Range Digital Multimeter

Milan

 

[bryce007]

no, i have got digital multimeter, witch automatic range..
one i was able to measure the current on my not pot moded laser.. it show me around 170ma

but after pot moding i am unable to check it.. multimeter just go UP and DOWN without showing any NORMAL drawing.
it seems that i am unable to check everything above 200ma..
i really dont know..

also i was pointet to change my batteries, but it didnt help.

i have got this piece of s... equipment.
DealExtreme: $10.40 Auto Range Digital Multimeter

Milan

Is it working accurately when measuring voltage? Take a look at this pic from DX:

http://www1.dealextreme.com/productimages/sku_9636_4.jpg

That glass tube with the metal on the end (above the batteries) is a fuse. If you accidentally measured a voltage when you where in Ampmeter mode, you could have blown the fuse, which will result in measuring errors.

 

[lazerov]

This multimeter can measure only up to 200mA current. Check this pic:
http://www.dealextreme.com/productimages/sku_9636_2.jpg
It's written on the plastic cover.

 

[milantheone]

Is it working accurately when measuring voltage? Take a look at this pic from DX:

http://www1.dealextreme.com/productimages/sku_9636_4.jpg

That glass tube with the metal on the end (above the batteries) is a fuse. If you accidentally measured a voltage when you where in Ampmeter mode, you could have blown the fuse, which will result in measuring errors.

it is working properly when i am measuring voltage, or resistance, or whatewer..

also my fuse is OK..

all right.. i have figured it out..

My perfect multimeter is really measuring current max to 200ma.. it is shame..
i found a manual, and it was stated here.. 2000mikroamps. and 200ma...
F...MeSideWays

 

[milantheone]

This multimeter can measure only up to 200mA current. Check this pic:
http://www.dealextreme.com/productimages/sku_9636_2.jpg
It's written on the plastic cover.

yep.. Thanx

 

[milantheone]

one more question guys..
as my batteries dont provide enough juice to dirive my laser properly i have to add another battery..

But this laser is supposed to vork with 3,1volts..
have you ever guys think that this big resistor could be a problem..???

as it is here to lower a voltage? or could you please explain to me what is it for?

What should happen if i remove it, or if i replace it with another one with lower or higher value..

i have 4 units which not worked properly.. i would like to try something.. they all have a same problem.. vith 3 volts they dim form 50mw to 5mw within couple of seconds and with 4,5 socked power suply they have stable output..

they all have a resitor vith 0,7-0,8 value..