NimH AAA to 5V, suggestions?

I've used Linear's LT1613 in a couple of small personal projects. They worked pretty well even with my non-ideal layout on a homebrew board. They have others that look promising that I haven't played with, such as the LT1307.

Have a look at Sipex SP6641A - I used it with 2 cells, but it is specced to 0.9 volts

On a sunny day (Mon, 02 Aug 2010 12:01:17 -0400) it happened Rich Webb wrote in :

I found it with google, conrad and mouser here do not seem to have either in stock. Will look aroudn a bit more. Thanks.

a 'soft'

LT1110 is nice, simple and seems like it will do everything you're after (supplied by arrow and farnell). It also comes in a SO or PDIP package so perfect for chucking on a lump of veroboard.

(I just wish I could find the couple I have sitting around somewhere. I know I will find them - just as soon as their replacements arrive by courier :-(

The trick is to put a regulator around it. The worst thing about a = fixed bias circuit is it cooks the transistor if your load opens up!

This works, if a bit cheezy:

Once the output voltage comes up, all sorts of regulation schemes can be = applied using slightly more voltage-hungry approaches (TLV431, etc.). = You could even use a small one to provide bias for a FET circuit, which = could keep working to arbitrarily low voltages (not that you can get any = current out of a AAA at 0.2V).

Tim

--=20 Deep Friar: a very philosophical monk. Website:

display,

is a bit a 'soft'

circuit is it cooks the transistor if your load opens up!

Ah! It's you! I'm trying to organise some of these circuits, now I have a name to put on the folder with this style circuit :)

applied using slightly more voltage-hungry approaches (TLV431, etc.). You could even use a small one to provide bias for a FET circuit, which could keep working to arbitrarily low voltages (not that you can get any current out of a AAA at

OT: Does Agent have a line rewrap function? I can't find it, would save me propagating Tim's endless lines when I'm too lazy to manually reformat (no I don't mean the line length setting, I need to break that sometimes too).

Maybe a solar panel too, get the most out of one.

Though now there's people trying to power sensors from environment, be alright if there was much energy to recover, and, if there was, it'd be taxed!

Grant.

It's quite a versatile circuit. Sometimes it blocks, other times it = runs resonant (cf. self-excited class C) or quasi-resonant, as per = recent discussion here.

Trying UUEncode this time.

Peak power point? The voltage and current vary depending on = illumination and type (fill factor). Voltage and current should be in a = ratio, i.e. constant impedance, though. Then again, V/I vary according = to the exponential curve (or resistive exponential, since solar panels = make bad diodes), which complicates things.

It's my understanding about Denmark that, instead of just taxing the = s*it out of the most important things (like income tax), they have large = taxes on *every puny little thing they can grab*. Like, remodel your = house, that's a tax. Buy a candy bar, that's a tax. Install an = electrical generator, that's a tax, oh and they tax the power too (so = you need a power meter). Fart and that's probably a carbon tax...

Tim

--=20 Deep Friar: a very philosophical monk. Website:

Oh, would help if I changed the setting...

Tim

-- Deep Friar: a very philosophical monk. Website:

Peak power point? The voltage and current vary depending on illumination and type (fill factor). Voltage and current should be in a ratio, i.e. constant impedance, though. Then again, V/I vary according to the exponential curve (or resistive exponential, since solar panels make bad diodes), which complicates things.

It's my understanding about Denmark that, instead of just taxing the s*it out of the most important things (like income tax), they have large taxes on *every puny little thing they can grab*. Like, remodel your house, that's a tax. Buy a candy bar, that's a tax. Install an electrical generator, that's a tax, oh and they tax the power too (so you need a power meter). Fart and that's probably a carbon tax...

Tim

-- Deep Friar: a very philosophical monk. Website:

UUencode is for binaries, but your headers say floormat (my fingers seem to have dyslexia? quite weird when typos like that come out of them :) format flowed, to one of the RFCs

Always wanted to play with solar power, but mains is so much cheaper.

We have a GST now in .au on most everything, plus larger duties & excise of the usual booze, smokes, petrol/diesel, etc.

But they still allow negative gearing for the smarter ones with a decent cash flow or clever accountants to avoid paying income tax.

Grant.

On a sunny day (Tue, 03 Aug 2010 10:04:48 +1000) it happened David Eather wrote in :

a 'soft'

That 8 pin DIP looks just what I need :-)

ed bias circuit is it cooks the transistor if your load opens up!

applied using slightly more voltage-hungry approaches (TLV431, etc.). =A0Yo= u could even use a small one to provide bias for a FET circuit, which could= keep working to arbitrarily low voltages (not that you can get any current= out of aAAAat 0.2V).

Tim, great, nice regulator. Did not see your reply in my newsreader, so I did see Grant reply, looked it up with google.

On a sunny day (Tue, 3 Aug 2010 05:56:40 -0700 (PDT)) it happened Jan Panteltje wrote in :

PS I build your circuit, and it works perfectly, even with almost empty NiMHs. Will make a little PCB for it, and use that, it seems more efficient then my version. No need to order some chip :-) Here is the setup, I use the box to switch between full and almost empty NiMH batteries. ftp://panteltje.com/pub/1.2_to_5V_converter_test_img_2249.jpg This is the collector waveform: ftp://panteltje.com/pub/1.2_to_5V_converter_Vce_img_2250.jpg The 7805 on the LED PCB is disconnected, I go in after that. Project page:

Thanks :-)

From the menu, View | Word Wrap, or just press the "O" key to toggle between wrapped and as-sent.

Thanks, I know of that one. I forgot to say I was after a line rewrap function for use while composing a reply, to rewrap the OP's post. Some user agents have that feature, but I can't find it on Agent.

Sometimes I'll rewrap manually, but it's messy putting in the '> ' in front of each new line. Or, I could rewrap a line, then cut the block and paste as quoted to get the '> ' fitted.

Is there an easy quicker way to do that in Agent?

Thanks, Grant.

version.

batteries.

So any old ferrite will do for a small converter? That one looks like a filter ferrite?

Grant.

Reformat in UltraEdit, then put in ">" with a macro:

:-) ...Jim Thompson

On a sunny day (Wed, 04 Aug 2010 08:43:53 +1000) it happened Grant wrote in :

version.

batteries.

Yes, this is the filter that IIRC was around the cable of an old keyboard (inside the keyboard). Most cores I try just work, a smaller one than this should work here too, but I have used all thsoe. Time is expert on magnetics, you do need a bit of permeability, else you need so many turns.

version.

batteries.

That basic circuit (less the OVP) looks very much like the joule thief circuit. There are lots of sites on this and here is two:

version.

batteries.

(inside the keyboard).

It's good to see something useful with so few turns. I tend to use storebought inductors so I know what value I'm dealing with, which is good for getting a switcher going easily. Not the cheapest way.

Grant.