O-like green driver mod

[FlightLevel350]

I have been trying to fit a o-like module in to a small host, but have been unsuccessful due to the length of the module. I cut the "extra" tubing off the front but it's still to long. I was wondering if it is possible to remove the driver from the module and replace it with a smaller one, like a flexdrive. I have disassembled a olike module before and it appears that it would be possible except that the diode is soldered to the driver in 3 places. What is the third pin for and it is necessary for the diode to operate? There is also the issue of what current the diode needs to be driven at.

FL350

 

[JLSE]

Though I have never bought one of these modules, I will try and lend a hand..

The third pin is reserved for feedback in an APC type board. I dont think I have ever seen one in use on modules outside of leadlight lasers and the like.

Have you measured the current draw of the module?

You can replace the driver with an AMC7135 which will give 350mA or 2 in parallel for 700mA. Again it depends on the current the module runs at, as is.

Using a 7135 will be your least expensive option, and the best space saver..

 

[Jimmymcjimthejim]

The problem with using a flexdrive is that the green module is case positive. So you can't use a flexdrive unless you isolate the module from the case. The AMC7135 is a good option but it might be too big, depending on how "small" your host is. Of course you could desolder the individual AMC7135 chips from the board and fix up a new board for them.
They can be found here:
DealExtreme: Search for amc7135 (6 products in 1 categories)

 

[Benm]

Before making any changes, measure what the current consumption is, and remember that.

You can proceed to desolder the board from the diode then, and replace the driver with something that delivers the same current as the original one. As said, the photodiode feedback is rarely used or even present in the laser diode. It IS usually soldered to the circuit board for mechanical stability only.

The AMC7135 is nice if you need ~350 mA or a multiple of that, and have to work with a limited voltage drop (otherwise it overheats).

 

[Morgan]

The problem with using a flexdrive is that the green module is case positive. So you can't use a flexdrive unless you isolate the module from the case. The AMC7135 is a good option but it might be too big, depending on how "small" your host is. Of course you could desolder the individual AMC7135 chips from the board and fix up a new board for them.
They can be found here:
DealExtreme: Search for amc7135 (6 products in 1 categories)

Hiya,

Isn't the case positive issue still there regardless of the driver used? Why would a Flexdrive change this? I only ask as I wish to change driver on a greenie too so this explanation would be welcomed.

Thanks,

M