I bought a couple of these laser drivers Variable Current Step-up (Boost) 405nm Laser Driver Board - Detailed item view - OdicForce Lasers Online Shop but I am having some issues setting the current. It seems to fluctuate a lot. I want to max it out to 500mA. Is it possible to bypass the pot to fix it to full power? If not, has anybody used them before?
LPF Donation via Stripe | LPF Donation - Other Methods
Links below open in new window
ArcticMyst Security by Avery
Odicforce laser driver help?
- Thread starter bhwollen
- Start date
- Joined
- Jan 14, 2011
- Messages
- 3,816
- Points
- 63
Should be fairly easy to bypass the pot. Just stick a jumper wire between the two leads coming from the pot (from the looks of it on the picture, I would say the top and the bottom left, but that may not be right because the traces aren't very clear).
- Joined
- Jan 14, 2011
- Messages
- 3,816
- Points
- 63
It should. Essentially, you are putting two things in parallel here: the pot and the jumper. Assuming the jumper has tiny resistance, you get this:
1/(1/0.000001 + 1/pot resistance) = a very small amount of resistance.
Generally speaking, the less resistance, the more current passes through, so this should max it out.
1/(1/0.000001 + 1/pot resistance) = a very small amount of resistance.
Generally speaking, the less resistance, the more current passes through, so this should max it out.
123splat
0
- Joined
- Jan 14, 2011
- Messages
- 424
- Points
- 0
Not exactly,, If the pot is used as a voltage divider (instead of a series limiter), then shorting the two end points sets the overall voltage drop to zero. Your circuit may need to have that oferall resistance. Better to short the wiper contact (the connection for the turny part on top) to the high end (where the wiper would point if set to max). Otherwise you stand a 50-50 chance of burning your driver.
- Joined
- Jan 14, 2011
- Messages
- 3,816
- Points
- 63
123splat, we may be saying the same thing.
The pot on this driver is like this:
..X..
X..X
for the solderpads, right? So I was thinking of connecting ONLY the top X to one of the bottom Xs, depending on which one is being used in the driver (it looks like the bottom left one).
The pot on this driver is like this:
..X..
X..X
for the solderpads, right? So I was thinking of connecting ONLY the top X to one of the bottom Xs, depending on which one is being used in the driver (it looks like the bottom left one).
123splat
0
- Joined
- Jan 14, 2011
- Messages
- 424
- Points
- 0
From your diagram, if you turn clockwise to increase current, short top 'X' with bottom RIGHT 'X' most likely (top 'X' represents wiper, which is usually the tap for the sense. Bottom 'X' represents the high side of the divider. If you turn clockwise to increase current, you lessen the path from the tap to the high sideof the divider, shorting the two connections really, really reduces the path).
chefla
0
- Joined
- Mar 24, 2011
- Messages
- 169
- Points
- 18
I am using the same driver in my 6x BR build. I only set it at 170mA and it works fine for me and is very stable at that current. I will be doing some testing with it tomorrow to find out where its limits are. If I can push it to 500mA without smoking it, I will be ordering another one for my upcoming 12x build. I am looking forward to your test results...
chefla
0
- Joined
- Mar 24, 2011
- Messages
- 169
- Points
- 18
Sorry, no time on the weekend to take apart my BR and measure the driver. But I will follow up in the next days.
@bhwollen, any success with your driver?
@bhwollen, any success with your driver?
rhd
0
- Joined
- Dec 7, 2010
- Messages
- 8,475
- Points
- 0
If I may speak to a more practical point -
That driver doesn't power a 405nm at 500mA
I know it says it does, but it doesn't. From memory, I couldn't squeeze any more than 380mA out of them.
That driver doesn't power a 405nm at 500mA
I know it says it does, but it doesn't. From memory, I couldn't squeeze any more than 380mA out of them.
chefla
0
- Joined
- Mar 24, 2011
- Messages
- 169
- Points
- 18
I am not surprised to read that it didn't make it to 500mA. I took some measurements earlier with odic's 80-500mA TTL driver and the max I got out of it was around 260mA, IIRC. I used two different types of batteries to make sure it was no battery issue.
I also bought two of their "high power" red drivers. One came with a sheet of paper stating 400mA+, the other 300mA+, same part number, same part.:thinking: Both can indeed do 300mA+, but beyond 300mA they become freaking hot. I replaced their drivers with 1085s in all my builds, except for the GGW. I am not saying their drivers are bad, but you should not expect them to stand up to their rated current output.
I also bought two of their "high power" red drivers. One came with a sheet of paper stating 400mA+, the other 300mA+, same part number, same part.:thinking: Both can indeed do 300mA+, but beyond 300mA they become freaking hot. I replaced their drivers with 1085s in all my builds, except for the GGW. I am not saying their drivers are bad, but you should not expect them to stand up to their rated current output.
rhd
0
- Joined
- Dec 7, 2010
- Messages
- 8,475
- Points
- 0
I think you could take one of the $15 "445 1W" boost drivers and it would fun a 405 at around 500mA.
Seeing as they really only boost a li-ion to about 750mA for a 445, the 6V of a 405 vs the 4.5 of a 445 might suggest that you'd get about 500mA out.
That's a really sketchy approach though, admittedly.
I also have a 405 12x running on an NJG-18 fairly well.
Seeing as they really only boost a li-ion to about 750mA for a 445, the 6V of a 405 vs the 4.5 of a 445 might suggest that you'd get about 500mA out.
That's a really sketchy approach though, admittedly.
I also have a 405 12x running on an NJG-18 fairly well.
