(SOLVED) I... I'm Kinda Retarded

[gazer101]

Alright folks, so I finally received a long-awaited driver from Aliexpress (https://www.aliexpress.com/i/33015299888.html). I was testing it out on a dummy load and seeing the potentiometer's range when, go figure, the cheap thing broke when I overturned it. The driver now outputs 3mA max...

Would any of you have any idea what resistance range a replacement potentiometer would need? Could I just salvage another button pot from a different driver and use it to replace this one? I would also be ok with replacing it with a resistor, but I have no idea what value I'd need (aiming for 1.8A output)

Any help would be greatly appreciated!



EDIT: Fixing the pot is out of the question, I've tried to no avail

 

[Cyparagon]

You may have just broken the wiper. Desolder it and measure the three resistances between the pins.

 

[gazer101]

You may have just broken the wiper. Desolder it and measure the three resistances between the pins.

Idk, my ree self threw out the pot after I broke it... What is the usual resistance range for laser drivers? Like could one of you guys just measure out the range of one of your drivers' potentiometers?
Thanks

 

[Lifetime17]

Hi,
Sorry about your mishap , just buy a driver from DTR
and you wont have to wait 5/6 weeks for a Chinese driver.
Rich

 

[hakzaw1]

yeah-- afaik hardly anyone buys from alibaba or the others in china that are about the same same.
IMHO any seller would be a better choice.. BUT buy from Jordan--
DTR has been a super friend to me and the entire forum.
He almost quit right after starting- It was my pleasure to help him get out/avoid what was about to happen. This was over a laser he had sold unknowingly to a kid who had gotten 'eye-flashed' and feared the injury was bad- AND in the middle of this post he THANKS DTR for selling him the (completed) laser-duh? (clueless) its history now..

hak

 

[lasersbee]

I would contact the seller and ask him the part value
or at least have him measure one.

Jerry

 

[gazer101]

Hi,
Sorry about your mishap , just buy a driver from DTR
and you wont have to wait 5/6 weeks for a Chinese driver.
Rich

Sadly I need to have a circular circuit board due to the constraints of my puny host. I'll do some research and let you guys know if I manage to rectify the situation. Also, I don't want to pay $20+ for a driver

 

[gazer101]

I would contact the seller and ask him the part value
or at least have him measure one.

Jerry

Thanks for the suggestion; I did but got no response yet

 

[Cyparagon]

threw out the pot after I broke it... What is the usual resistance range for laser drivers?

Okay, well, you just made this a lot harder on yourself. Because the pot could be as low as 100ohm or as high as 100kohm depending on the design. If you can decode what the main switching regulator is, that would help.

However, if $20 is too high a price to pay to fix your mistake, that's indicative to me this entire venture is a waste of time.

 

[gazer101]

Okay, well, you just made this a lot harder on yourself. Because the pot could be as low as 100ohm or as high as 100kohm depending on the design. If you can decode what the main switching regulator is, that would help.

However, if $20 is too high a price to pay to fix your mistake, that's indicative to me this entire venture is a waste of time.

Perhaps I should opt for a more traditional linear-voltage-regulator-based design? I could get all the components from my local store for cheap, wire it in such a way that it fits in my host, and the heat shouldn't be too big of an issue since my duty cycle is so short anyways. My LiIons could handle the reduced efficiency with no problems.

Do you have any recommended designs for a 1.8A non-buck current regulator? I see tons on the internet but want to hear it from you guys since I don't really know what I am doing (yet)

 

[Lifetime17]

Sadly I need to have a circular circuit board due to the constraints of my puny host. I'll do some research and let you guys know if I manage to rectify the situation. Also, I don't want to pay $20+ for a driver

Hi,
Whats the diameter and the amps ? What will you be setting it to ?
Rich

 

[gazer101]

Hi,
Whats the diameter and the amps ? What will you be setting it to ?
Rich

I need <20mm diameter that can output 4-6V at 1.8A (powering a 1W green LD). It can be up to 5mm tall

EDIT: I want to build the circuit myself using linear regulators, so ideally the design shouldn't require too too many parts

 

[Encap]

Hi,
Whats the diameter and the amps ? What will you be setting it to ?
Rich

Looking at the sellers link for the driver, in the product descriotion It says:
"Wavelength:445nm 447nm 450nm
Recommended working voltage:3.7V lithium battery (16340,18650,14500 and 18500 powered), or directly using a 5.5V DC power supply
Circuit control:5.5V boost circuit
Reverse Polarity Protection:None
Diameter:17mm
This is a power supply driver for 445-450nm 1W-1.4W laser diodes! "
No other specs. No range of Amps of output listed/specified.

The OP says he was aiming for 1.8A which may not be possible with that driver in perfect condition anyway, so...
The specs seem imply to the driver output is much lower than 1.8A and meant to drive whichever 445/450nm diode to 1W to 1.4W --only 0.9A to 1.25A is needed depending on diode type and what 445/450nm output between 1W and 1.4W is desired.

 

[gazer101]

Looking at the sellers link for the driver, in the product descriotion It says:
"Wavelength:445nm 447nm 450nm
Recommended working voltage:3.7V lithium battery (16340,18650,14500 and 18500 powered), or directly using a 5.5V DC power supply
Circuit control:5.5V boost circuit
Reverse Polarity Protection:None
Diameter:17mm
This is a power supply driver for 445-450nm 1W-1.4W laser diodes! "
No other specs. No range of Amps of output listed/specified.

The OP says he was aiming for 1.8A which may not be possible with that driver in perfect condition anyway, so...
The specs seem imply to the driver output is much lower than 1.8A and meant to drive whichever 445/450nm diode to 1W to 1.4W --only 0.9A to 1.25A is needed depending on diode type and what 445/450nm out between 1WW and 1.4W is desired.

Yeah, the seller is quite sketchy. When I was buying it they told me it could go "up to 2A", but they just messaged me saying its made for 1.6A... Anyways, I'm making my own driver using an LM338 and this wonderful diagram (Source: https://laserpointerforums.com/threads/i-really-dont-understand-drivers.66469/page-2):

 

[gazer101]

Yeah, the seller is quite sketchy. When I was buying it they told me it could go "up to 2A", but they just messaged me saying its made for 1.6A... Anyways, I'm making my own driver using an LM338 and this wonderful diagram (Source: https://laserpointerforums.com/threads/i-really-dont-understand-drivers.66469/page-2):

Before I decide to actually build this thing, would any of you guys like to chime in and confirm that I would be needing TWO 4.2V LiIons to run this thing? From my understanding I would need to be inputting like 8V in order for this thing to work right?
Eagerly awaiting an educated response

 

[gazer101]

Aight folks, I got the thing to work but it needs a pretty high input voltage in order to output enough voltage. Idk what I'm doing really, so is there some way for me to make it so that the circuit boosts the 3.7V from a regular battery up to the correct output voltage? Or if not is there any kind of compact battery that outputs high voltage (12V+ with less than 18mm diameter and 35mm height).


Looking back I would honestly be totally ok with buying a $20 driver from DTR, but the issue is that all his drivers are on awkward rectangular boards that won't fit compactly in my host. I looked at this SL driver (https://www.survivallaser.com/Survival_Laser_Fixed_Current_Driver/p556088_7425633.aspx), but the darn thing needs 2 batteries (4.2V+) to run since it has no boost circuit!

Long story short, do you know of any circular 1.8A laser drivers that can operate (without making too much heat) off of just one LiIon battery?
Please help me out here