12V LEDS over Arduino

[FSAddon_boss]

I found a nice set of LED lights for my cockpit, but they are 12 V.
Is there a way to power them with a 12V adapter, but have them controlled via the Arduino Mega board (using Mobiflight).

If so, how?

[KyleH]

Use a 5V relay.

[RayS]

You could also go the solid-state route with a ULN2803A driver chip.

https://www.ti.com/lit/ds/symlink/uln2803a.pdf?ts=1644515601197

[ame]

How much current do the LEDs take?

Powering from 12V is very easy- you can just use a transistor buffer- but you need to account for the current draw. Probably no big deal for one LED, but becomes significant if you want a string of them.

An alternative is to see if you can open the LED assembly and rearrange things so that the voltage requirement can be dropped to 5V. This really depends on how the "LED" is constructed. The LED dies themselves typically require about 2V.

Do you have a link to the LEDs you have bought?

[FSAddon_boss]

I think I have a plan now.
I have a second Arduino, a 12 V adapter, 14 12V leds, and read that I can link them thru 14 BCD547 transistors.
That way I can power all the LED lights in the panel and keep the Arduino Mega running all the switches and rotaries.

https://www.amazon.it/gp/product/B08PK93N7S/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1

[ame]

Ok. There is nothing special about those LEDs. They are regular LEDs with a dropper resistor already soldered on. You could make them yourself, and you could choose the resistor value so that the LEDs were bright enough at 5V. In fact, you could connect those LEDs to the Arduino directly- they would work, and you won't damage anything, but they will be a little dimmer than they could be.

Because they are regular LEDs you can assume that the forward current will be less than 20mA. Probably less than 10mA.

[FSAddon_boss]

Thank you Ame !