Custom XHP70.2 LED lightbar - Stuck on Regulators

Other Types of Lights LED Headlamps
1

Hey Everyone,

This is my first post here, My appologies if it doesnt fit under LED headlights, I dont intend to drive with the LED lightbar but I figured it fit here better than anywhere else. ( Unless it belongs under DIY flashlights)

I am attempting to retrofit an existing inexpensive LED lightbar with XHP70.2 LEDs. I found a very cheap LED lightbar that has 6 single diodes behind some marketing BS “8D” reflectors. I removed the driver board and diodes from the existing lightbar chassis and installed 6 XHP70.2 Diodes on heatsinks in the stock positions but I am at a loss for the driver(s). As a temporary soltion I found a TOBSUN converter to limit both the voltage and current ( 12V @6a) to power 6 of the LEDs in parallel but i would like to get away from external regulators and design a circuit board to handle the current and voltage limiting.

So here is my question, Does anyone have experience designing driver circuits, or know of someone I can speak with?

I am looking for either an existing regulator that runs on 12-14V and outputs 12v@1A ( I would use 6 of them to driver each LED indapendently ) to install in the exisitng housing or a regulator design that i can have a PCB printer like JLPCB print for me to mount in the existing chassis.

Thanks in advance.

Cheers

2

I think it’s not too hard to find 12 Volt 1 Ampere drivers for indoor use on Chinese webshops.
Those are usually AC and DC compatible, but you can bypass the rectifier diodes.
I think i’ve seen 900 mA ones here and there.

3

thanks for the response.

Ive seen a handful of indoor ones but they all seem to be rated for 120v input rather than 12v that and they are huge compared to the drivers for led flashlights.

Im hoping to find something that I can fit in the existing lightbar case without too much other modification.

4

Maybe search for GU16 driver will give you results.
There are often 2 pins on them to stick into a 12 Volt halogen socket.

I’m on my phone this week and have crappy mobile internet, otherwise i would have a look for you.

5

I looked for the GU16 driver and didnt see anything. I did find a few that run on 12v AC but i haven’t seen anything for 12-16v automotive in and 12v output at regulatred 1a.

I did find a few things on digikey but they are all rather expensive given what they are. Comparing them to the external 12v 3a regulator I found for $20 it might be more realistic to just deal with the external regulator.

It might be something to design from scratch but I fear that I dont have the experience in electrical circuit design to handle it on my own. Does anyone have any experience designing LED drivers from scratch. Maybe with a custom parameter list :stuck_out_tongue:

6

I made a mistake in thinking you can use a buck driver, because your power supply is too close to the 12 Volts you need for those LEDs.
If i were you i would look for 6 Volts buck drivers.
Cheap 1 mode 4 Ampere drivers for XHP70 you can find on AliExpress.
You could run 2 LEDs in parallel so they get 2 A each at 6 Volts, which is the same power as 1A at 12 V.

7

I may have made a mistake in ordering 12v LEDs.

I currently have 6 12v LEDs and a friend has 8 more with the same plans. I havent completed any of my prints for the LED chip mounts so Im still flexible as to the configuration.

I could wire them in a 2s3p for 24V@1A(3x) but the 24V units I’ve seen are much to large to fit inside the confines of an LED lightbar.

8

Buck boost converters could your savior:
https://www.aliexpress.com/item/LTC3780-DC-5-32V-to-1V-30V-10A-Automatic-Step-Up-Down-Regulator-Charging-Module/32817780222.html?spm=2114.search0604.3.30.2033700dQsF9Uk&ws_ab_test=searchweb0_0,searchweb201602_5_10065_10068_10130_318_10547_319_317_10548_10696_450_10084_10083_10618_452_535_10139_534_533_10307_532_204_10059_10884_323_10887_100031_320_321_322_10103_448_449,searchweb201603_35,ppcSwitch_0&algo_expid=84c54a98-ae81-4f7d-bda8-035994b1389b-4&algo_pvid=84c54a98-ae81-4f7d-bda8-035994b1389b

These should work very well in your build case if you set the output current to say 6A, and then strip off the voltage potentiometer, and wire in with long wires and a potentiemeter with a knob.

By doing this, you can vary the voltage until it goes to the max current set by the buck boost converter, and by definition, be able to vary brightness.

ALSO, BTW, what makes an XHP 70.2 is not the LED itself, but rather the MCPCB it sits on. Just get a 6V MCPCB instead of 12V :slight_smile:

9

Oh, i see, you bought XHP70.2 on 12 Volts LED boards.
The LEDs themselves can be used as 6 Volts or 12 Volts, depending on the LED boards they’re on.

10

Hey all,

I know it’s a old thread but the guy Hawkbait mentioned as the friend with more LEDs, is me. This project still isn’t any further then 2018. Held up finding drivers and we’ve recently purchased some cree xhp70.2 6v LEDs as we think the driver selection may be greater. If we are shooting for the same thing, automotive voltage of 11-16v and 6v @ 4.8a each what are your suggestions for a driver source? I don’t mind running 2 LEDs in parallel at 9 or 10a but finding a driver that meets our needs is redicously challenging. I’m hoping with 6v LEDs we only would have to worry about buck converting and not boost converting. Looking for ideas. End goal is a retrofitted lightbar

Many thanks in advance,
Steve

11

High current drivers are expensive so you need to reduce the current. My opinion is the best way to do it is to wire in series and boost the voltage.
6LEDs x 6v = 36v
So 6 leds can run off 4.8amp at 36v