How to mod this laser

[crampedson]

I have this laser
http://www.newwishlaser.com/english/productview.asp?id=657

The potmod does not seem to work at all on it. Anyway I CAN mod it? It has the A106 capacitor but no 103 resistor.

 

[dr_lava]

That board looks like the lightvision APC model.
Corona did a very fine job with that one here. (see the PDF)

Unfortunately the boards don't let you search for APC MOD because they are three letter words. If there's a way, let me know!

 

[rapt]

Was it easy to get apart? I have one of these lasers as well that I want to mod.
Was your laser a 20mW to start off with?

 

[BlueDraco]

Please write how did you open it?

My laser looks almost the same and I am unable to disassemble it. Iwould like to acoid scratches and any other damage if possible.

 

[cbfull]

Have you tried measuring the current? That would be a good place to start, to make sure the diode is not already at maximum current.

 

[figaro]

That board looks like the lightvision APC model.
Corona did a very fine job with that one here. (see the PDF)
:goodjob:
Unfortunately the boards don't let you search for APC MOD because they are three letter words. If there's a way, let me know!

Thank you, perfect link, the Corona mods are OK.
Looking only for reasonable increased power for astro use, I made the things simpler :
1. Dismantle by twisting (hard enough) alternatively right and left with two nutcrackers.
2. Added only two piggyback resistors (so I could quickly restore original configuration : 1 ohm upon R103 (double threshold of current limiter) and 1000 ohms across R102 (increase tuning action of pot) : they're side by side.
3. Starting from minimum, I trimmed the pot slowly until 380 mA.

Piggyback addition is much easier : you put a drop of solder-tin at each end of the resistor to add, then maintain it upon its sister and melt the tin by the tip of a little fsoldering iron : that's all.

 

[dr_lava]

MM, congrats. another 'newbie' who's self-teaching and knows what he's doing. Just a note: 380 mA is a lot of current, I'd add ceramique or other heatsink grease to the diode and to the sides of the rearmost crystal if I were you. Also, you may want to follow a duty cycle. If you observe the beam getting dimmer on a good set of batteries, immediately turn it off for a while.

 

[abeland1]

Thank you, perfect link, the Corona mods are OK.
Looking only for reasonable increased power for astro use, I made the things simpler :
1. Dismantle by twisting (hard enough) alternatively right and left with two nutcrackers.
2. Added only two piggyback resistors (so I could quickly restore original configuration : 1 ohm upon R103 (double threshold of current limiter) and 1000 ohms across R102 (increase tuning action of pot) : they're side by side.
3. Starting from minimum, I trimmed the pot slowly until 380 mA.

Piggyback addition is much easier : you put a drop of solder-tin at each end of the resistor to add, then maintain it upon its sister and melt the tin by the tip of a little fsoldering iron : that's all.

"1. Dismantle by twisting (hard enough) alternatively right and left with two nutcrackers."

It is Friday afternoon and I am thoroughly enjoying this thread. If your efforts do not succeed, be sure to return the item to the seller and demand a refund. LOL

 

[figaro]

MM, congrats. another 'newbie' who's self-teaching and knows what he's doing. Just a note: 380 mA is a lot of current, I'd add ceramique or other heatsink grease to the diode and to the sides of the rearmost crystal if I were you. Also, you may want to follow a duty cycle. If you observe the beam getting dimmer on a good set of batteries, immediately turn it off for a while.

To be honest, I'm not self-teaching, I'm a teacher ... about electronic. And with this excellent Corona's scheme...the hard job was done.
:goodjob: Yes, it's a lot : beyond the 410 mA limit, the efficiency decreases !!! => This tuning is for intermittent

use only.
My first mod was much more prudent and still simpler : only shorted R102 by a strand of copper wire. Then tuned the pot until max current response. So the original current limiter was still doing its job between 250 and 300ma (I don't remember well alas) and actually, from the practical point of view, it was sufficient and secure ! I estimated (green LED) power around 8 mW.
It's quite enough for astro conferencing or as a telescope pointer.
But I'm haunted by the "always-more"

daemon, then ...
Does anybody achieved optical collimation ? (this daemon ...

...) I mean with this lightvision model.

 

[crampedson]

Couldn't get back for a while. On to business... My laser drew 260ma of current unmodded but strangely enough, would not respond to the pot at all. Then the APC mod was done but still only 260ma of current was drawn no matter where the pot was. Removing the IR Filter/Photosensor Reflector boosted the current draw to a steady 310ma, the maximum current limit. Any clues as to why turning the pot doesn't work?

Rapt and BlueDraco, what I did to remove the laser module was to use many layers of cloth over a pair of pliers then grip the metal head with the curved part of the pliers. Then wiggling little by little from side to side the head was removed.

 

[figaro]

Couldn't get back for a while. On to business... My laser drew 260ma of current unmodded but strangely enough, would not respond to the pot at all. Then the APC mod was done but still only 260ma of current was drawn no matter where the pot was. Removing the IR Filter/Photosensor Reflector boosted the current draw to a steady 310ma, the maximum current limit. Any clues as to why turning the pot doesn't work?

Rapt and BlueDraco, what I did to remove the laser module was to use many layers of cloth over a pair of pliers then grip the metal head with the curved part of the pliers. Then wiggling little by little from side to side the head was removed.

The 260 mA limit results of APC. The 310 mA limit comes from current limiter.
You'd better to restore APC and choose between the mods Corona proposed or the mines : it's no use to improve pot action (R102 etc.) if tou don't modify the current limiter (either R105_Corona or R103_me) ! APC is useful, better modding it than suppressing !!! It allows stable work in spite of variations of context and exhaustion of cells.