Understanding a Small LED Flashlight Circuit

Thread Starter

Zohar

Joined Nov 19, 2015
70
Hi all

I have a small single-LED flashlight that I took apart,
and I am interested to understand the circuit inside it.

The flashlight works on a single AAA battery,
and here are pictures of the circuit inside:


Front:




Back:




On the front, I assume that the black component with 3 legs is a transistor?
It is labelled "2603".

And aside it is a capacitor?

And on the back we have an Inductor.

So can you please tell me what is this circuit?
and why is the Inductor needed?

Thank you
 

SLK001

Joined Nov 29, 2011
1,513
It's probably a voltage booster circuit, since a white LED (I'm assuming that it is white output) requires 3+ volts while the battery only provides 1.5V
 

Thread Starter

Zohar

Joined Nov 19, 2015
70
Hi SLK001 and thank you for your reply..

Yes it is a White LED..
And I thought too that it might be a voltage Boost circuit, but could not confirm it myself..
If it is, then the 2603 SMD component is not a Transistor, but some kind of Voltage Boost IC?
 

Thread Starter

Zohar

Joined Nov 19, 2015
70
I see, thank you very much.


I have another flashlight circuit, this time it's not an LED, but a COB.
Similar to the previous one, this too is AAA operated:


Front:



Back:



Zoom on the Circuit:




So it's the same circuit here?

There is probably an inductor, just a boxed boxed type, which makes it less obvious as an inductor.
I can guess that the inductor is the biggest boxed component - the one on the bottom..
 
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