Don't understand the "continuous" negative path in the flexdrive

[bbshamsa]

Hi all.

After checking out, I still can't completely get my head around the wiring methods for the flexdrive vs the microboost.

I totally understand the microboost method where you can use the case pin wired to the driver -ve input to feed current into the driver from the diode case via the host body, it makes sense, but I don't understand the "continuous" -ve input and output design of the flexdrive, and why it requires a different wiring style, or what advantages/disadvantages it offers.

I always get lost when reading that if you use a 405/445 diode with a flexdrive, then you can just attach the diode case pin to the diode -ve pin, and solder both to the driver negative output connection.

Is the safest (for the diode), most reliable way to wire a 405/445 to a flexdrive to use the same technique as for microboosts? By which I mean soldering an isolated wire from the diode case pin to the driver -ve input, and soldering both the +ve and -ve diode pins to their corresponding driver +ve and -ve diode connections?

Ultimately, if I understood what the continuous part of the flexdrive meant, I'd likely understand the difference between the two main wiring styles, I think.

Any help appreciated, of course.

Thanks.

 

[drlava]

What continuous means in this case is just that the -Vbatt and -Vdiode on the FlexDrive are electrically connected. So assuming your host case is connected to - batt, you can use the case-connected - diode pin as the battery connection also and leave -Vbatt unwired.

With the MicroBoost you would have to run a wire from the case diode pin to -Vbatt on the driver in the same situation.

 

[DTR]

I always use the isolated wire from the case pin to the driver negative input with both the Flex and Microboost. Even thou it is supposed to work by bridging the diode pins. But I am a creature of habit.:beer:

 

[Mohrenberg]

in short, on a flex drive, only the positive must go through the driver, and on a microdrive, positive and negative must both go through the driver.
On blu-ray & 445 diodes , the negative path is fed into the case pin, which is wired into the driver, travels through the driver and into the - pin on the diode.


This is the way i view it.....

 

[Elektrotechniker]

in short, on a flex drive, only the positive must go through the driver, and on a microdrive, positive and negative must both go through the driver.
On blu-ray & 445 diodes , the negative path is fed into the case pin, which is wired into the driver, travels through the driver and into the - pin on the diode.


This is the way i view it.....

So you don't have to use the negative pin on a 405 or 445 diode ?

 

[DTR]

So you don't have to use the negative pin on a 405 or 445 diode ?

What they are saying is if you are using a flexdrive you can bridge the negative pin and the case pin and you don't need any wire going to the driver negative input just the positive in and out and the negative out to the bridged negative and case pins.

 

[AUTO XX]

That is specifically why I got the flexdrives.
One wire going through the heatsink means the hole can be smaller and that means more bulk is maintained for heat transfer.
Between the silicone wire from flaminpyro and the flexdrive from lava, my latest heatsink has a 1/16th hole through it, a pressfit (milled down) aixiz module and the driver will be heatsinked to the same chunk of aluminum at the other end. (the drivers haven't shown up yet)
Compact with improved heatsinking properties FTW!!! :crackup:
I really like the technology the enthusiasts are coming up with now. These lasers are becoming more reliable all the time, a few more steps in this direction and they will be viable for a multipurpose survival tool.

 

[bbshamsa]

I always use the isolated wire from the case pin to the driver negative input with both the Flex and Microboost. Even thou it is supposed to work by bridging the diode pins. But I am a creature of habit.:beer:

Yeah, well this approach seems the one I'll take too as at least with this approach it seems to be using the driver to handle the negative input.

I know what I just wrote will probably highlight my misunderstanding about circuits and this one in particular, but I understand that current flows from -ve to +ve, and as Dr. Lava states...

What continuous means in this case is just that the -Vbatt and -Vdiode on the FlexDrive are electrically connected. So assuming your host case is connected to - batt, you can use the case-connected - diode pin as the battery connection also and leave -Vbatt unwired.

With the MicroBoost you would have to run a wire from the case diode pin to -Vbatt on the driver in the same situation.

... Then, to me, this would mean that the current flows directly into the laser diode before even reaching the driver (from host case, to diode case and pin, straight to diode -ve in).

I thought the current had to be regulated by the driver, in which case I thought it would at least have to flow through the driver before reaching the laser diode in order to be regulated.

I know I must be missing something here and not actually questioning the design of the flexdrive, and as long as it doesn't cause any harm, will continue to use the same method for flexdrives as DTR does; wiring the case pin to the driver -ve input.

I just feel a bit thick doing it without knowing precisely why I'll be doing it.

Thanks everyone for your comments though, really helpful

 

[532 with Envy]

Geez I feel like fool among scholars but thought that I would put my two cent in.

I have used the Flex-Drive and Boost-Drive for 445nm builds...also I should put out there I, myself, am still trying to get my head around the subject of your thread(English lit major:beer
In my last 445nm build I used the flex...I did not use the case pin of the diode....I Did use the (-) in to the driver and 'crimped' the wire between the heat-sink and host...to get my negative from the battery.

[/IMG]

When I used the Boost-Drive on a 445nm I did use the case pin and connected it to the (-) in to the driver..and it worked(as stated above)
I hope that this doesn't confuse more...I am a visual learner...(thanks DTR for your great pics!) Hope this shows what worked for me with the Flex-Drive