Electronic – Light LED light

conductancecurrentdriverledled strip

I would like to mount 10 or 20 white LED on a thin rod, about 2 m long – and around 3 mm in diameter.

I will need to accept various compromises for conflicting requirements,
but I try to understand the basic feasibility for now, so let's just ignore tradeoffs.

An important requirement is, that the mass of the LEDs is as low as possible – it's important to keep the total mass of the rod low.

I would start with the smallest standard SMD white LEDs – are there obvious candidates for?

The total or individual intensity of the LEDs is a minor conocern.

But I think the mass of copper wires to deliver enough current using a low voltage may be a problem. Embeding conductors in the rod itself would be at least tricky – but a possible option.
But, in principle, one could use a higher voltage, with less current, and convert it back at each LED – but that would need SMD packages containing the converter and the LED, to not double the part count. Are there LED modules that can be driven by somethink like 50 V – and preferably small?

In general, is there something like chip on board (COB) LEDs I could make use of, without
a machine that bonds the die directly on the actual device?

It's ok if it's hard to implement, because I build only one piece.

Other wild ideas that come to mind:
Does a standard SMD LED have some part that is not needed here and can be removed?
Is it sensible to use SMD LEDs with almost no heatsink, at somewhat reduced power?

So, do you see alternative approatches, or problems in mine?

If I can not easily use a higher voltage, it looks like
I should use 12 V,
and basically need a normal LED stick, minus the stick.

Best Answer

As a one off project, this sounds like a simple enough thing to do either with off the shelf led strips (single white 3258 smd with 15 or 30 count per meter), attach to (or replace) the rod with some rigid led bars, or use some of the super thin led strings (fairy lights). All of these are bare minimum smd leds, thin wire or copper tape, and resistor.

At typically 20mA per led, even if they are all in parallel, 20 leds at 3.5V and 20mA that is only 1.4 Watts. Conductor size is mostly electrically unimportant here.

The rest is making it look pretty.