use USB-C for powering LEDs

Flashlight Modding and DIY Parts
1

Hello everyone.

I have a question that if I can solve, it will fix most of my problems of portability.

I’m a light artist, and often I work where there’s no power outlets so I have to depend on batteries for my sculptures. I’m using a powerbank with DC out but it is limited in capacity so I was trying to go for a 20000mah powerbank.

I was wondering if there is a way to use the usbc port of a powerbank to power my lights, as the port support more voltage (if I have understood correctly)

My classical setup is this:

2 rebel LEDs in serie with a 1A driver, meaning around 6V@1A (6W of power).

is there a way to simply connect it to the usb powerbank?

thanks!!!

2

Yes, but you need a USB-C trigger. A QC power bank and a QC trigger can also be used.
You can fairly easily buy cables that split the USB plug into power connections, or you can cut an existing cable and use the two power wires directly.
QC3 has variable voltage, USB-C and QC2 is usual in fixed steps of 5-9-12 and also 15-20 for C volt.

Here are some triggers for higher voltage:
https://lygte-info.dk/review/USBmeter%20PD-QC%20trigger%202D001.html
https://lygte-info.dk/review/USBmeter%20QC2-QC3%20trigger%20UK.html (This trigger supports QC3 variable voltage)
https://lygte-info.dk/review/USBmeter%20QC2-3-MTK-PE%20Trigger%20J7-t%20UK.html

This is how I use it for testing USB supplies:

3

that’s very nice to hear, thank you

the other thing that may work or not and I’m sure you can answer:

what if I put each one of the led with a 1A driver on a normal usb port, does it work for the powerbank? so 3v@1A on each port

thanks

4

You can use a led without driver, you just need a resistor in series with the led, a 2ohm (or 2.2ohm) 5W would probably work fine. This is not as efficient as a switch mode driver (A linear drive may give you problems with heat).

5

could probably hook that portion up to something like this if you wanted to make it more flexible right?

6

I normally use this one but lowered to 1A

https://www.ebay.es/itm/LED-driverLDMINI-1-5A-1-5A-DC-5V-25V-for-XHP50-XHP70-XP-L-XM-L-L2/113691430284?hash=item1a78898d8c:g:2R0AAOSwaDZapTLv

as I need something reliable and fixed: often I’m not the one plugging it, so the person who does mustn’t have any choice to mess it up!

do yo think that if I connect a qc trigger + this driver + 2leds it works?

or one of these drivers to each port and each led to the usb out of the powerbank?

7

It looks like it would work with with QC 12V or PD* 12V/15V/20V in and 1 to 3 leds in series on the output.

*PD is Power Delivery and is the USB-C name for power output.

The red one I showed on the picture will remember selected mode and automatic restore it when power is applied.
I have also seen some triggers where you can solder a link to select output voltage.

8

I bought the red one but it will take time to reach Europe…but it looks exactly what I need…

anyway I found here in a shop the third one, the one with the display. from your review I can’t understand if it has memory and it basically is the same one as the red just with a display. if you say so, I’ll buy also this one to star testing various solutions.

thanks again HKJ, your knowledge and dedication is very very helpful!!!

9

It may have memory to remember mAh and Wh, but it do not remember and restore selected QC mode, you have to trigger it each time you power on.

10

USB C may be a little more complicate. why not just use regular usb A port from powerbank? Easy to get at least 10W, but make sure you have some current protection!

11

that would be even better, but how?

can you explain better what you had in mind?

the thing is that the driver need 2.5v over the total voltage, so 3v+3v+2.5v = 8.5v. that’s why I thought about usb-c that have a higher voltage, but off course usb3 is good as well…