SMT inductor value help or advice pls...

Okay, I etched out some boards for the lm 3410. I must first thank 'woop' for posting his thread for this nice little boost circuit.
I am trying to figure out the value of the inductor. In woops board and the pdf for the 3410 it calls for a 4.7uH inductor, now on the cheap side, seeing as I am just trying this out, I would like to find the value to some inductors that I already have.

After discussing this with a few people I have found that there is no universal markings on these components. Inductors are marked by the manufacturer with whatever they feel, and there is no way for the average test equipment to find this value. Hopefully that is wrong, and there is a way to find it.

The inductors I have are marked -22 ON-, anyone have an idea for their value? I got these from a local surplus outlet for free and have approx 50 of them, hence the desire to use them. From what I found the 4.7uH inductors are labeled 33. Is there enough tolerance with the 3410 to use the coils I have? I dont want to blow any parts, but will if I must.

Here is a pic of the first set etched. I am still working out the kinks in the etch for these tiny boards.

If you have a regulated bench supply, you could bring the voltage up and watch the current to see how it works using a dummy load. It might simply change the switching speed.

Mike

The current seems to be good with a 10ohm resistor,and a 63ohm load, but the voltage may be an issue. I have to assemble another one, my first off got meltdown syndrome It was the only board I didnt check the trace after etching.... Still smoothing out the etch process ;D

After some coaching from IgorT ( Super Genius )  and some persistance, voila!! 5.12v from 3v DIY ;D


The resistors were a bit tricky, and had to stack 4 (paralell) to get the desired current

Nice work there congratts ;D

john_lawson said:

Nice work there congratts ;D

Click to expand...

Thanks Although I did pull out a little too much hair on this one :-/ But the hardest part is over, it works

I still have to take a nice macro of the finished board, the one in the pic at the top of the thread failed.

It aint the greatest pic, my camera seems on the fritz :'( But here it is
mmmmmmm, DIY booost!

Nice little boost PCB... What are the dimensions??
I don't see a pot... will you make them adjustable in the future??
Are you going to sell them or did you just make them for yourself??

Questions... questions... so many questions... ;D ;D ;D ;D ;D

Its tiny Woop has a thread in here somewhere, he wanted it to fit in the rear of an axiz module, and that it does. As for selling them, doubtful, maybe the odd one, they take too much time to assemble and I think another member is selling something similar. I just wanted a driver for my bluray builds that didnt require me coughing up 20$ a pop