LED diodes in series, parallel or designated driver for each?

Flashlight Modding and DIY Parts
1

Hello everyone,

Planning on creating a lighting device that will used six XHP-70.

Whats the best option to set this up? I know series isn’t the best, because if there is an open circuit (one diode dead) the whole series will not work.

So is it better to parallel all six with one driver or get an individual driver for each?

Or a combination of 3 drivers with 2 in parallel?

Thanks in advance.

2

How many amps are you wanting to send to each emitter? Also, the XHP-70 can be used at ~6V or ~12V depending on how the MCPCB is wired. Which voltage are you using?

A single driver can be sufficient, as long as it can handle the output that you’re trying to reach. It’s also a lot more simple to build that way.

3

Yeah its what I thought.
I think using 12v will be better and delivering 3 amps for each diode.

If one diode dies (in a parallel of six), will the current increase to all the other 5 diodes by 3amps/5?

Where can I find a driver that delivers 12volts and 18 amps? (3*6)

4

Running at 12V will be better if you have a good 12V source to use. Drivers that have been designed right here at BLF can easily give you that 2.5A per LED. But, you’d have to order the PCB and components and build the drivers yourself. You could order from Richard at Mountain Electronics, but you’re in Australia, and I don’t know how shipping will be for you. What you need is a Linear driver with either Zener Diode or LDO to use the higher voltage. You could use a FET driver, but that won’t give you any current regulation, so the LEDs will get all the current that your source can give, which might be too much. Also, as you suspected, if one LED does die for any reason, the current will be deferred to the other LEDs.

Edit: 3A per LED will work too. :partying_face:

5

So i need to build a driver myself? Can it have a low medium and high output modes, where high output needs to be 18 amps?

6

I recently started building my own drivers. Even though it was not the easiest of tasks I found the results to be very rewarding. Especially if you need multiple drivers it is cheaper building them yourself.

The most difficult aspect (for me) was the size of some parts, it was very difficult for me to even see some of them or even read whats on them. a magnifier helped.

you can have any outputs you flash onto them, if the firmware is compatible with the driver. But even changing the firmware and adjusting the values is not that difficult.

edit:
have a look at this thread:

Oshpark Projects (oshpark projects @ BLF)

7

Oh yeah, you can have practically any modes you want! Just like we have people here designing driver boards, we have people writing firmware practically all the time. Use the Search box at the top left of the screen to look up two of the best driver firmwares currently available - Bistro (by ToyKeeper) and Narsil ( by TomE). If neither of those is exactly what you want, go to ToyKeeper’s firmware repository and look at some of the other choices that are out there. Also, if you do end up looking at Mountain Electronics, you have several of these excellent drivers and firmwares to choose from there, already built and coded to order!

8

Thanks, i guess there is a lot for me to learn! I plan on doing this project to make a final product. Hopefully for larger production size too :slight_smile:

9

Yeah I’ve heard of Toykeeper, even have a few lights with his driver in it.

I would like it all built and ready, it would help me speed up the process as ill have to do a lot to design the rest to be water proof at the same time and run on a battery pack and/or power outlet.

10

By the way, ToyKeeper is female. :smiley:

If you have a driver with her name on it, it is likely using her firmware. She doesn’t design hardware.

11

Thats a surprise! Thanks of letting me know. Good to see ladies also in the flashlight industry.