Leadlight GPL-110 Modifications

LaserMod

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Hi all,

There has been a lot of people emailing me about mods (once again) for the 110 pointer (the one with the red LED on it). I haven't got one to experiment on at the moment but I did work out a small resistor mod on the last one I had.

With thanks to 'bootleg2go' for the excellent driver board images. /ubbthreads/images/graemlins/thumbsup.gif

Front:
110_front.jpg


Back:
110_back.jpg


Looks easy to work out doesn't it...thats what I thought /ubbthreads/images/graemlins/icon23.gif

I might try feeding the circuit into Tina Simulator to see if I can come up with anything.


What we know so far:

1. The red and black wires that disapear into the diode are the wires for the feedback module - cutting these WILL disable the pot completely - so don't do it!

Some info on the feedback assembly here:

http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Board=lasers&Number=771382&fpart=&PHPSESSID=

[ QUOTE ]
(Just a quick word of warning - if you have this model, remove the clear plastic cap for the LED from the housing before removing the circuit board or you will snap the button of like I did but just a bit soldering put it back on again.)

[/ QUOTE ]

I think the feedback module is there for better constant/stable output as you'll notice the removal of the IC chip on the back of the board. I can certainly confirm that the model I had made the needle on the meter jump all over the place without the FM. /ubbthreads/images/graemlins/jpshakehead.gif

Feedback.jpg


2. The pot on these models turns CLOCKWISE for extra power the opposite of the 105's.

3. The red LED acts like a fuse and is quick to blow with too much current.


The single pin on the diode (back of the driver board) is the cathode or positive/case of the diode.

The two pins on the opposite of the diode (front of driver board) - the bottom is NC and the top is the anode from the drive circuitary.

The No Connection pin I have read is for an un-used photo sensor of some sort.


As always the post is an educational reference only and I take no responsibility for damage to yourself, others, or the pointer - I still have yet to verify this mod - (it worked the first time round). The mod is provided as my other posts as a free exchange of information between myself and others who are fascinated by the technologies. /ubbthreads/images/graemlins/smile.gif

***To modify I have no idea what to do about the feedback module but to get a boost of current of about another 50-80ma - short the resistor marked 102 on the right of the pot. /ubbthreads/images/graemlins/grinser2.gif

Cheers!

Edited, wrong resistor...sorry I didn't have the board to hand.
 

dyter

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Re: Leadlight GPL-110 Information

How many mw and ma can you take with the GLP-110 compared to the GLP-105 without resistor mod and LDR remove ?
I think the LDR is in replacement of the PD.
 

LaserMod

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Re: Leadlight GPL-110 Information

Website back online.

Images should display now ... /ubbthreads/images/graemlins/grin.gif
 

LaserMod

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Re: Leadlight GPL-110 Information

Same as the 105's, about 180ma > 320ma at max of potentiometer.

Don't have a clue about the feedback module...best just to leave it on if you want a stable leadlight. /ubbthreads/images/graemlins/thumbsup.gif

What about diffusing the beam... with a piece of plastic from sunglasses maybe...put directly on top of the photo-sensor. /ubbthreads/images/graemlins/thinking.gif
 

dyter

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Re: Leadlight GPL-110 Information

Is the GLP-110 better than the GLP-105 with the pot mod ?
 

DaFiend

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Re: Leadlight GPL-110 Information

[ QUOTE ]
LaserModifier said:
What about diffusing the beam... with a piece of plastic from sunglasses maybe...put directly on top of the photo-sensor. /ubbthreads/images/graemlins/thinking.gif

[/ QUOTE ]

I was just thinking this course of action. Some sort of filter, but nothing to far out???? But you beat me to the punch. /ubbthreads/images/graemlins/smile.gif
 

LaserMod

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Re: Leadlight GPL-110 Information

Yeah we could put a piece of 532nm filter glass over it. /ubbthreads/images/graemlins/grin.gif

The driver board would think it was outputing really low and give us a light sabre... /ubbthreads/images/graemlins/smile.gif

*If only it was that simple* /ubbthreads/images/graemlins/icon23.gif

I think it will brighten up the beam slightly?

I've been studying the circuit where the feedback wires seem to provide a resistance between the Pos and the top of SMR 103 which is connected to the pot. I have found cutting these wires disables the pot so that screwing it does nothing to the power /ubbthreads/images/graemlins/frown.gif but the power is left at about half (estimate).

The same feeback module is found in the UK version of the 105. This is a standard 5mw GPL-105 but with a feedback module - the output is fed back to provide just 1mw of legal UK power. /ubbthreads/images/graemlins/icon23.gif

Anyway cheers DaFriend... /ubbthreads/images/graemlins/smile.gif anyone else got any 'brightening' ideas?
 

Bengal

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Re: Leadlight GPL-110 Information

If you put a resistance in series with the feedback wires then the laser would have to go higher in order for the circuit to detect the same power. .. maybe a pot in line with the PD?
 

bootleg2go

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Re: Leadlight GPL-110 Information

I tried increasing the resistance of the 10k ohm resistor ( the resisitor marked "103" that is above the pot and connects to the red feedback module wire) from 10k to 21k and that did increase the brightness somewhat for me. If anyone else does this as well or trys other mods to increase the power, then post here and let all know.

Jack
 

liteglow

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Re: Leadlight GPL-110 Information

i want a 110 model /ubbthreads/images/graemlins/wink.gif
 

Kingjamez

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Re: Leadlight GPL-110 Information

I just replaced the 332 resistor that is in line with the pot with a short. I got no difference in the draw of the diode at all. No matter how the pot is turned I get a maximum of 230mah. Turning 90% of the pot seems useless and about 10% of the turning actually moves the current. I think I'll try putting a resistance in line with the feedback circut. Any other suggestions?
-Jim
 

Bengal

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Re: Leadlight GPL-110 Information

For those who have access to the 110 driver board.
The pictures are good, but there are some shadows that prevent tracing the circuit.
If someone can get better photos that can show the traces clearly I am trying to get a schematic made.
Thanx
 

Wyvern

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Re: Leadlight GPL-110 Information

[ QUOTE ]
Bengal said:
For those who have access to the 110 driver board.
The pictures are good, but there are some shadows that prevent tracing the circuit.
If someone can get better photos that can show the traces clearly I am trying to get a schematic made.
Thanx

[/ QUOTE ]

I have one of these on order, i will take los of high definition pics and send then to you as they will be quite large images
 

Double_E

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Re: Leadlight GPL-110 Information

[ QUOTE ]
Bengal said:
If you put a resistance in series with the feedback wires then the laser would have to go higher in order for the circuit to detect the same power. .. maybe a pot in line with the PD?

[/ QUOTE ]

Thats a good idea, although, usually the resistance of a sensor decreases with light intensity. Thus, you should place a resistance in parallel to the feedback sensor. Although, bootleg2go said he increased the resistance and it helped, so I might be wrong. Either way, by adding a resistance in series or parallel, one way will work. From there, I think you'll get a brighter beam that is also more stable than the 105. Also, I have a feeling that turning the pot down to where it decreases the output then turning it up a little will result in less wear on the regulating circuit.

By the way, I'm new here, I've been reading the posts for a few weeks now and have a new pointer on the way. I'm an electrical engineering student pursuing a Ph.D. in power electronics. I don't know much about optics, but I know a bit when it comes to electronics. Thanks for the time! /ubbthreads/images/graemlins/smile.gif
 

Kingjamez

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Re: Leadlight GPL-110 Information

Well, I got tired of messing with the feedback circut today and unsoldered the feedback wires and shorted the connections on the driver board. The laser operates exactly as it did before and the pot still does nothing. I'm stuck at 240ma.... the search for more power continues.


-Jim
 

bootleg2go

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Re: Leadlight GPL-110 Information

High Double E,
If it's like you said that the sensor decreases in resistance as the light intensity go up, then any resistance in parallel with the sensor will decrease the resistance that the feedback circuit sees right? So, decreasing the resistance by putting a resistance in parallel with the sensor will be tell the feedback circuit that the laser is brighter than it really is, thus the feedback circuit will try to compensate by reducing the current to the diode and that will reduce the brightness.
So putting extra resistance in series will help make the laser brighter if the sensor resistance decrease with increased brightness and putting a resistance in parallel with the sensor (thus reducing the resistance) will help make the laser brighter if the sensor's ressitance increases with increased brightness.

Jack
 

bootleg2go

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Re: Leadlight GPL-110 Information

[ QUOTE ]
Kingjamez said:
Well, I got tired of messing with the feedback circut today and unsoldered the feedback wires and shorted the connections on the driver board. The laser operates exactly as it did before and the pot still does nothing. I'm stuck at 240ma.... the search for more power continues.


-Jim

[/ QUOTE ]
Hi Jim,
What happens if instead of shorting them, you just disconnect the feedback wires and leave th4e circuit open?

Jack
 

Wyvern

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Re: Leadlight GPL-110 Information

i think, rather than a ldr it uses a photodiode which actually would produce small amounts of current, correct me if i am wrong
 

LaserMod

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Re: Leadlight GPL-110 Information

Just found my 110 driver board I thought it went out in the trash... /ubbthreads/images/graemlins/smile.gif

I haven't got the FM attached anymore but I have a hi-res image of it somewhere.

I'll post some pics later on... /ubbthreads/images/graemlins/grin.gif
 

Double_E

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Re: Leadlight GPL-110 Information

Jack: Right on, since we don't yet know exactly how the feedback works, it is still hard to say exactly what will help, but I think your right that the resistance should probably be added in series.

Wyvern, if that is true, then it opens a whole new bag of worms. That would probably mean that we have a transistor controlling the power. In that case, we would have to bias the input to increase the current to the transistor.

Anyway, this can all be determined from experimentation. Kingjames, it sounds like you have it running with the wires disconnected, check the sensor with a volt-meter to see if it is producing a voltage (or a current for that matter) if not, check it with the ohm meter to see if the resistance is the changing variable. From there, we should be able to get an idea as to how it works. (Actually, I don't care as much how it works as why, i.e. we want to tell the unit that the laser is not outputting at a high level, and that the power needs to be boosted.) Whats cool about this is that we might be able to maintain the true purpose of the feedback unit, which is to generate a beam that is more constant than the 105, thus increasing the performance for applications other than just pointing.

Thanks

Sean
 
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