Abate Holding Your Breath...Thompson's Design

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So which one of you guys is Cope, and which is Marsh?

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Sure, why not?

ftp://jjlarkin.lmi.net/Hub_Alt_1.JPG

The step-down transformer gives the roughly 2:1 power/current boost. The SSR (could be a pfet) is controlled to charge the battery to its happy voltage. The control circuit is powered from the generator, not from the battery. We only need to sense the battery voltage, which takes microamps, not a discharge issue.

This is simple and very rugged. It can be switched off for minimum drag and the light can - special feature! - be turned on and off!

The control block is simple: regulator, UVLO, comparator to drive the SSR. Transzorb for luck, like the way garlic keeps vampires away.

Of course there are no values yet. One has to agree on function and architecture first.

Let the discussion (or the whining, if that's what you're good at) begin.

John

The bike dynamos I've seen have a mechanical disconnect that moves it away from the wheel, so you don't need a switch on that. Just one on the lights.

It's amazing how much consulting you can get for free here. Try getting free solutions with this much effort on programming or IT groups.

Can a comparator really sense up to it's positive supply? Surely not all of them.

And wouldn't it depend on which side of the 'diode' it is powered from?

That's a _rim_ driven dynamo.

I try, but Larkin is so full of hate that it makes it difficult to conduct a back-and-forth what-if discussion. ...Jim Thompson

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I suggest that you recall that I said that the hub dynamo, at least as we have a model for, doesn't give you the boost you claim.

But, indeed, the circuit you present cannot be challenged... as usual it has no component types or values. ...Jim Thompson

Remember the ripple detector post I made in response to _your_ question? That TLV3501 has a common mode range that extends about

Plus all the ones I design to do that ;-) It's _really_ easy to do with CMOS. That latest chip design of mine had two rail-to-rail (I/O) OpAmps and 8 rail-to-rail (I/O) comparators.

Sure. But we know, in the hub dynamo case, which way we want current to flow. From experience with those sims, I'd probably set it for +1V of margin before I let the switcher go, with a resistive or diode dropper, ...Jim Thompson

Or alt.hvac they are the Rodney Dangerfield of technicians. The think they get no respect, they show how much they know by not giving out their knowledge. Mikek

The original topic relates specifically to hub 'dynamo'.

Rubwheel 'dynamos' have huge drag when engaged and obviously won't be topping off the battery when disengaged.

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

Remarkable - a troll who doesn't want credit for his own handiwork!

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

You've tried so hard to trash this thread, and finally succeeded - so no one GAF anymore.

Is JT the hairy one?

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Of course I recall it. You're probably wrong. What's the difference here between a step-down transformer and a fixed-duty-cycle buck switcher? Both allow the alternator to deliver more power by better impedance-matching the load.

So challenge it on architecture and function. The things you got wrong. There's no point in designing the little control block until we agree on whather the overall concept is usable on a bicycle, in real life. (Actually, it has one issue. See it?)

Whine or discuss. The world is watching.

John

Then why did you "diss" me when I immediately had a behavioral switcher architecture RUNNING in SIMULATION?

You're just an asshole.

Nope. I'm right. I even said why. But you're too dense to understand.

Significant.

Show component types and values. Otherwise "discussion" with you is a total waste of time.

Anyone who wants to chime in and agree with Larkin shall be labeled unemployable ;-) ...Jim Thompson

Because it was a trivial theoretical cartoon, in fact just some waveforms. And it was a variable-duty-cycle switcher, which is *not* what you ultimately posted. In other words, it was all show but useless to the discussion at hand.

So, you have chosen whining over discussing electronics. I knew you would.

I don't recall you explaining why. Why?

Explain why.

You posted a useless, defect-filled simulation of a dumb buck switcher, with values, that would be useless if built and put on a bicycle. You won't even discuss the things that a real product would need.

You probably don't even ride a bicycle, so you wouldn't appreciate the issues. Like the biggest problem with my proposed design.

Things like component selection, values, packaging, and cost can't be sensibly discussed without a definition of the problem and an architectural approach to solving it. Probably, as a contract linear IC designer, you're not used to working at that level.

John

Actually, I do kind of look like the one on the right.

John

I agree. It looks overcomplicated. Besides that, over here bicycles have AC dynamos.

I never saw one of those. Is it built into the wheel?

I think there might have been a little provocation.