Minimum component efficient voltage regulator

Oh - and vero/bread-boardable so SMTs are out. (Don't want much do I ;-)

I thought I'd better pop that in :)

Does this work for you?

Thank you! Using some of the terms in the description led me to:

(Farnell, UK) my usual supplier. And dirt cheap (for what they are) at about 3 quid - most acceptable. I'm thinking the 3.3V driven from 4xNiMH cells should work over about 1/2 the useful capacity of the cells (down to about 1.1V per cell), better to use 6 cells - which is still OK but will use the entire capacity of the cells.

You can get SMT breakouts from Bellin Dynamic Systems. They come in V-grooved sheets of various assortments. Here's a proto that has one in it, to hold an LTC2602 dual DAC:

I put header strips in the DIP pattern, and mounted it on some foam double-sticky tape.

Cheers

Phil Hobbs

I was going to say "bit tag board" to the PP but I did not want to appear rude ;->

I must admit I have never seen that approach done with modern components and I say that with the greatest of respect!

Speaking of voltage stability, I've had significant success using the basic base-connected zener diode regulator. Converts 5V to 3.3V, which is within your specifications. The only significant drawback is that the zener might require significant (read: unacceptable) current to be stable and also that it draws power all the time.

Put a low current incandescient lamp in series with the bias R, drop the value of R down a bit and you'll get some extra help on the biasing as the current in the zener drops due to demand.

Old trick, used years ago in old stuff!!!!!!!!! :)

Some even used that same bulb for a panel light and could tell when the power supply was on demand because the lamp would dim!

Jamie

Yeah, but mine was built last week, whereas yours was obviously salvaged from the wreck of the Titanic. ;)

Here's another one from a couple of years ago--it's a dual SMPS and demod box for a transcutaneous blood constituents sensor.

Cheers

Phil Hobbs

Yeah, but mine was built last week, whereas yours was obviously salvaged from the wreck of the Titanic. ;)

Here's another one from a couple of years ago--it's a dual SMPS and demod box for a transcutaneous blood constituents sensor.

Cheers

Phil Hobbs

I am wondering how hard it will be to do a home grown regulator with a MOSFET which would not impose a 2V forward voltage drop? Something that could clip 0.5-1V off a battery pack when they are fully charged, clipping virtually nothing when they are at their nominal 1.2V output and permitting operation when the voltage falls further (I could allow LEDs to dim when the batteries are on their last legs - they would at least be regulated over 80-90% of the range).

It is a bit fiddly--wiring up those four SO14 flip flop packages took way longer than it would have with DIPs. Wire wrap wire is flexible enough, but if you just wire them up with cut-off resistor leads as usual, you'll twist the pins right off the package. I did cheat and wire them up individually on the bench under my Mantis.

The little Bellin boards plus pin headers make it almost as fast as with DIPs--I'd never have got that MSOP8 working dead-bug style without one.

I needed this one because my current main customer sprung an internal deadline on me with zilch notice, and I had to scramble madly to get results or get cancelled. (Fortunately, I started getting nice pictures on Thursday.)

Dead bug is still faster and better than Vero board. (Vector 8007 isn't bad--it's pad-per-pin with a ground plane, so you can do a bit of both methods on one board. Expensive though, compared to eBay copperclad.)

Cheers

Phil Hobbs

What about using a step up regulator ? There are some on ebay from China as well as the step down switching regulator boards. They are only a few dollars including shipping.

So tell me again what's wrong with a three terminal voltage regulator? There are bucket loads to choose from.

George H.

MCP1703

"Low DropOut" aka LDO?

I have not come across that term - but it makes sense now - putting your chip into Farnell found a whole category of "LDO" regulators:

with fantastically low dropout voltages. Bookmarked now :)

That was incredibly useful - I'll get some of those.

Thank you!

Tim