Cam453
0
- Joined
- Jun 8, 2011
- Messages
- 169
- Points
- 0
Anyone use this driver for the new Mitsubishi diodes? 635nm 300mw-500mw Laser Diode Driver
LPF Donation via Stripe | LPF Donation - Other Methods
Links below open in new window
ArcticMyst Security by Avery
635nm 300mw-500mw Laser Diode Driver
- Thread starter Cam453
- Start date
- Joined
- Apr 22, 2009
- Messages
- 401
- Points
- 28
I've bought from qualifound and they are good folks to deal with, but personally I would not use that driver.
I just did not like the way the specs read: IE, it's pretty large in size and might be difficult to make room for in a handheld, and I didn't like the explaination for this: constant current at 6.5V input, but later states recommended voltage to be 3.7V, so what's the current at a 3.7V input?
Then again, I'm not an electronics engineer or even a tech, and it might be perfectly acceptable to the other members here.
I just did not like the way the specs read: IE, it's pretty large in size and might be difficult to make room for in a handheld, and I didn't like the explaination for this: constant current at 6.5V input, but later states recommended voltage to be 3.7V, so what's the current at a 3.7V input?
Then again, I'm not an electronics engineer or even a tech, and it might be perfectly acceptable to the other members here.
Last edited:
Johnyz
0
- Joined
- Jul 19, 2010
- Messages
- 421
- Points
- 0
It is... a bit big, but looks like a buck driver to me.
BTW, nice avatar, Mark.
BTW, nice avatar, Mark.
- Joined
- Sep 12, 2007
- Messages
- 9,399
- Points
- 113
^based on what?
Johnyz
0
- Joined
- Jul 19, 2010
- Messages
- 421
- Points
- 0
8-pin IC: check.
big transistor: check.
big schottky: check.
three caps: check.
potentiometer paralleled with a smaller resistor: check.
OVP zener + resistor: check.
6.5V input: check.
poorly designed driver board: check.
diagnosis: a cheap chinese buck driver.
big transistor: check.
big schottky: check.
three caps: check.
potentiometer paralleled with a smaller resistor: check.
OVP zener + resistor: check.
6.5V input: check.
poorly designed driver board: check.
diagnosis: a cheap chinese buck driver.
ped
0
- Joined
- Nov 25, 2008
- Messages
- 4,889
- Points
- 113
Dont buck drivers need inductors?
Johnyz
0
- Joined
- Jul 19, 2010
- Messages
- 421
- Points
- 0
I'm pretty sure the inductor is that big white resistor looking thing... The way it is connected corresponds to it.
- Joined
- Sep 17, 2011
- Messages
- 11
- Points
- 0
lm 317 driver ftw :bowdown: 
lazeerer
0
- Joined
- May 25, 2010
- Messages
- 3,655
- Points
- 0
That big white thing is a Resistor Flip Upside down.
If you scroll up to the main Picture next to the Price you can see it.
Johnyz
0
- Joined
- Jul 19, 2010
- Messages
- 421
- Points
- 0
1R0 could mean 1uH... there are inductors made in 1206 or 0805... But even if it's not a coil, that would mean it's some weird design and not a switched one... But why the schottky and transistor then?
ped
0
- Joined
- Nov 25, 2008
- Messages
- 4,889
- Points
- 113
Yup, it doesnt look like any buck driver ive ever seen?
Johnyz
0
- Joined
- Jul 19, 2010
- Messages
- 421
- Points
- 0
Seems like we have a couple of options here.
- Weird switched design that doesn't have an inductor
- The inductor is hidden somewhere (the big "resistor"?)
- Weird ULDO linear design that uses schottky and transistor
rhd
0
- Joined
- Dec 7, 2010
- Messages
- 8,475
- Points
- 0
Guys, this is a regular old linear driver. Where's the mystery?
That white thing IS a resistor, there's no ambiguity on that point. No inductor, so not a boost/buck. It requires 6.5V input to drive an LD with a Vf of 3, so it's a step-down, and a fairly inefficient one.
This is linear. Why they need 3 ICs to accomplish this is beyond me.
That white thing IS a resistor, there's no ambiguity on that point. No inductor, so not a boost/buck. It requires 6.5V input to drive an LD with a Vf of 3, so it's a step-down, and a fairly inefficient one.
This is linear. Why they need 3 ICs to accomplish this is beyond me.
Last edited:
Johnyz
0
- Joined
- Jul 19, 2010
- Messages
- 421
- Points
- 0
Wait! Maybe it's just the LM317 type regulator, built without the IC? That would explain the 8-pin(op-amp) and the transistor. Then we could just call the diode a protection diode, and it would be all explained.
There's one IC... The DPAK type is marked Q1, thus it is a transistor of some sort, and that small little three pin thing is marked D, so it is a (double) diode, possibly used for making the 1.25V ref voltage.
There's one IC... The DPAK type is marked Q1, thus it is a transistor of some sort, and that small little three pin thing is marked D, so it is a (double) diode, possibly used for making the 1.25V ref voltage.
midias
0
- Joined
- Mar 14, 2010
- Messages
- 631
- Points
- 0
probably just an opamp comparator switching a fet.
rhd
0
- Joined
- Dec 7, 2010
- Messages
- 8,475
- Points
- 0
Again, a fairly poorly designed one if it drops 3+ volts. Given that, I don't know why they wouldn't have just used an LM1117 instead of the complexity they went with.
