check this out from national semicon...

[rhd]

I'll have a bit of time next week. I put together a board. If it works, I'll give the schematic used to the thread/board.

I like the low component count of the 3410.

 

[rhd]

I can't say too much before I get copyright on my product.... but my driver which is in DEV, will have very similar components, but of higher quality than the ones mentioned in this thread :shhh:

How do you get copyright on a product?

It strikes me that you could probably get copyright on a PCB layout, or the trade dress (visual appearance of your product), but I question whether you hold a valid copyright on a schematic or circuit.

 

[bobhaha]

Copyright on the PCB layout and design. Patent on the schematics

 

[Ghostchrome]

Patents are pretty expensive, at least in the US. They cost about $10,000 here in assorted fees, which is absolute bs. So unless you plan on making that up in sales (you won't - at least not selling it to hobbyists) it's not worth it. I hope Australia is different because 10k is just plain robbery.

 

[mark-in-dallas]

Patents are pretty expensive, at least in the US. They cost about $10,000 here in assorted fees, which is absolute bs. So unless you plan on making that up in sales (you won't - at least not selling it to hobbyists) it's not worth it. I hope Australia is different because 10k is just plain robbery.

Most of that goes to the Patent Attorneys for preparing and submitting paperwork, that no layperson could ever figure out.

That's what happens when you have attorneys writing the rules.

And, the cost of getting a patent issued is nothing compared to the cost of trying to later inforce a patent violation.

But, thats nothing compared to the cost of bringing a new drug to market, due to corporate monopoly influence on government.

 

[bobhaha]

This is getting off topic... but here's a link to patent fees in Australia

Patent fees | IP Australia

 

[rhd]

Hey,

What do you guys think of the component choices I made here?

 

[foulmist]

hey rhd,


what's the inductor current rating?

the shottky is a no go - your choice is 500mA average rectified current
but according to the datasheet your diode must meet this

Idiode ≥ Iout

and you are trying to run the output at 1.46A right?

I coudn't find the inductor current?
:beer:

 

[rhd]

hey rhd,


what's the inductor current rating?

the shottky is a no go - your choice is 500mA average rectified current
but according to the datasheet your diode must meet this

Idiode ≥ Iout

and you are trying to run the output at 1.46A right?

I coudn't find the inductor current?
:beer:

HCM0703-8R2-R
- Inductor current is 4A

Diode
- How about an SS23 ?

 

[foulmist]

yes ss23 is ok for up to 2A

i have put ss34 on mine just to be safe
the inductor should be ok then

when are you planning on testing this?
you should carefully design the pcb too... the layout and tracks size is very important too :beer: see the datasheet for pcb layout specifications

 

[rhd]

yes ss23 is ok for up to 2A

i have put ss34 on mine just to be safe
the inductor should be ok then

when are you planning on testing this?
you should carefully design the pcb too... the layout and tracks size is very important too :beer: see the datasheet for pcb layout specifications

If I get some time to do the PCB layout tonight, I'll order a couple with the next Dorkbot Panel. I'll post the Eagle files here too so that everyone can share in the fun, lol.

If people want to critique the design, I'd be happy to mail everyone who makes a meaningful contribution to the effort a few boards. I'll name it the "Free Boost" We'll put the Eagle files out in the public, and I'll get 15 or 20 of the boards made up to spread around. I seem to have stuff in with Dorkbot almost every panel now anyway.

EDIT: BTW, I tried to choose an inductor at least partially based on whether it looked hand-solderable while sticking within the parameters this IC called for.

 

[foulmist]

great,

if you could find a smaller size inductor that will sustain the current
it will be awesome

I always make the smd pads for the inductor a little larger so that I can
easily solder them by hand with the soldering iron touching the pad part that sticks out
... the solder will melt underneath the inductor leads and make the joint happen

actually I do that on all smd components with tracks under the chip...
well for limited types of smd of course... the complicated ones I solder with
hot air or infrared..

I will be happy to comment and test out your design when your are done :beer: can't wait actually
:wave:

 

[benmwv]

rhd, sorry I couldnt comment earlier but I'm already making an lm3410 driver and it is practically finished. The plan is to release it and about 5 other drivers and misc boards to the community, board files, parts list, and all AND to have mohrenberg to sell at least the lm3410 boost along with the linear drivers he is currently selling.

It will most likely end up being cheaper to buy it from mohrenberg than make it yourself because of bulk discounts and how expensive digikey's shipping is, but still i like the idea of sharing it that way people can make improvements to it also.

I'll pm you and show you all the stuff I've been working on :beer:

 

[rhd]

I will be happy to comment and test out your design when your are done :beer: can't wait actually
:wave:

Well, full disclosure, when it comes to designing boost drivers, at even a very fundamental basic level, I have absolutely no idea what I'm doing

I'm more or less just reading datasheets and fulling in gaps in my knowledge where I can. Don't put too high hopes on my design.

rhd, sorry I couldnt comment earlier but I'm already making an lm3410 driver and it is practically finished. The plan is to release it and about 5 other drivers and misc boards to the community, board files, parts list, and all AND to have mohrenberg to sell at least the lm3410 boost along with the linear drivers he is currently selling.

It will most likely end up being cheaper to buy it from mohrenberg than make it yourself because of bulk discounts and how expensive digikey's shipping is, but still i like the idea of sharing it that way people can make improvements to it also.

I'll pm you and show you all the stuff I've been working on :beer:

^ Here's the guy we should put our hopes on

In all seriousness though, I'm enjoying this just for the sake of it. I have orders going in to digikey every couple weeks anyway. Plus, they only charge me $8 shipping on a $100 or so order - that's not so bad?

 

[benmwv]

In all seriousness though, I'm enjoying this just for the sake of it. I have orders going in to digikey every couple weeks anyway. Plus, they only charge me $8 shipping on a $100 or so order - that's not so bad?

Pm sent.

What I meant was that it would be more expensive for a person who is making around 1-3 boards. $8 is about the total part cost of my lm3410 board so you can see how that shipping would greatly increase cost, especially if you only want to do one board.

I know what you mean about just enjoying it. I love making boards on eagle, they are like high-tec puzzles.

 

[HIMNL9]

Uhm, sorry, but i think this must be said, also if it can blow some dreams

When reading datasheets and designing switching mode drivers, there are some facts that must be kept in consideration .....

First, when you read "Switching current 2.1A", it does NOT mean that the driver can do 2.1A ..... that is only the INTERNAL switching current ..... and, indicatively, for buck drivers, the maximum safe current that you can obtain is half of this current, where instead for boost/sepic drivers, the maximum safe current is usually 1/3 of this value (i said "safe" current intentionally ..... overdriving the chip you can reach some more current, also 2/3 for buck and half for boost, but this stress a lot the chip, putting it in a non-safe working condition ..... this can end in a failure, and if this is acceptable for a LED, is not so much happy when it happen with your high-cost new LD connected )

Same is for the inductor saturation current, that must be choosen usually AT LEAST the double of the expected output current, sometimes also 3 times higher.

As example ..... i got one prototypes with LM3410X that reached 1.2A and worked for long time (heating a lot, heatsinked, and using a 10uH 4A coil), but also burned another one with the same current ..... the normal output current for a LM3410 chip used as boost/sepic driver, is around 800 / 900mA, and this chip is marked as "2.8A" switching current ..... it can be increased a little, using larger output capacitors, but then the driver becomes "a bit too big"