Led not working

I went through the artwork to make the rgb led.
But it doesn’t work.
I don’t know why.

tell me if you have any data you need

help me plz

Hi @lum_in_ous

Do you have a schematic?
A PCB without components is not easy to decipher.

Recategorised as Projects as more likely to be a design issue than a KiCad layout issue, until proven otherwise.

I am a non-professional. Share Gerber files and BOM, schemetic pictures.

gerberdata__.zip (58.9 KB)
led_change-top-pos.csv (2.1 KB)

I don’t understand the circuit, except that it’s some kind of buck LED driver from the IC model. But I notice that the LEDs driven by IC1 and IC2 are entangled, for example the bottom LED anode starts from IC1 but the cathode is connected to IC2. Can this be correct?

Yes, that’s right. IC1 to IC3 are intertwined with each other as positive and negative.

I haven’t checked the right hand side, but:
D0 is reversed
What is the input voltage?

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The input voltage is 11.1V and it is a battery.

Is the diode direction wrong?

Where did I go wrong?

I assume the Zener diode (you may want to change the symbol there to an actual zener diode symbol to avoid confusion) D0 could be the problem here. I think you want to use it to protect your circuit from voltages above 13V, right? If so at least the direction is correct but you have another problem: the diode only can survive a reverse current of about 10mA but you probably need a lot more to supply the circuit let alone the 9W LED.

If you want an overvoltage protection on the input a small FET-circuit or even a dedicated overvoltage controller would be a better solution here.

The connection of the drivers is all wrong. Please start with AL8860 application note to see how it should be connected.
Your circuit will not work as shown, at all.

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If so, is the diode’s orientation and circuit diagram a problem that the diode cannot withstand the DC voltage?

D0 is the wrong way around, blocking current to the rest of the circuit, which is probably a good thing at the moment.
It is stopping the magic smoke.

no, it is how you want to use the diode, it will simply not work this way. you can’t use a zener diodes for overvoltage protection on power supply lines.

And you also should take a look into what @fred4u said.

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There seem to be a number of problems with this project. In order to get help, it would be a good idea to describe exactly how you want this project to operate and what it is to accomplish.

Ah-hah! It is a 13V zener…I hadn’t looked "till now. Agree with everything you write.

Based on a quick comparison with the basic application circuit shown in the DI datasheet, I heartily agree. The chip appears to be a buck switching regulator that is turned around to drive the cathode end of one or more (series LEDs that have the anode end connected to +Vinput. ) The SW pin needs to drive the inductor, and I do not see that connection in the schematic shown by the OP. Also the freewheel diode appears to be reversed. I offer a (hasty but professional) opinion…I have been designing power supplies for >40 years…the schematic design appears to be completely hosed.

Thanks everyone for the good comments

I plan to completely revise the schematic.

What are the most important considerations when choosing a BOM?

I non-professional

The symbol of the zener diode I saw is as in the picture.

I know the current flow from the cathode (-) to the anode (+) when schematically, but is it the opposite case?

For example, the flow of current flows from the anode (+) to the cathode (-)


Hi @lum_in_ous

Before worrying about a BOM (Bill of Materials) you need to get you design working.

There are very many design considerations you need to both ask and answer yourself.
Here is the start of a very long list:
You have a 9W RGB LED. How bright do I wish to drive these? 9W is a lot of power which is a lot of current which produces a lot of heat.
Do I need a heatsink?
If so, where & how big?
Will any heat produced be problematic to other components?
Do I wish to control the output of the LEDs?
If so, independently?
What power supplies will I need for these LEDs (current output, adjustability, etc.)?
How will I adjust these supplies (voltage controlled, pulse width modulation etc.)?
How do I make the adjusters?
Are the adjusters on-board or remote?
Does my 11V input supply enough current?
What safety features do I need?

The list goes on and on, but you should get the idea.