DC to DC Converter 1V to 5V

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D How about a pair of germanium transistors as common emitter amps, the collector of each driving the base of the other forming an oscillator... should run down to about .2V or whatever a germanium transistor vbe is. Run the square wave from the collectors into a step up transformer, and Bob's Yer Uncle.

This application note explains it pretty well:

Just don't expect an efficiency worth writing home about.

--
Regards, Joerg

http://www.analogconsultants.com/

Something like the MAX866 is what you want. Works down to 0.8V

Maxim give free samples ;-)

Dave.

What sort of load current?

Dave.

I think they recommend the MAX1678 for new designs. However, if this is for mass production be careful WRT availability. Digikey says zero stock on the 1678. Why am I not surprised about that?

--
Regards, Joerg

http://www.analogconsultants.com/

Try the

LT3400. It works down to 0.85 volts. The attached LTSpice simulation shows an efficiency of 87%, driving 5 volts into 100 ohms. I don't trust the simulator so much since I got over 300% efficiency on a previous model, but this seems about right. They claim 92% typical.

They also have an LTC3401 which runs at 3 MHz and has synchronous rectification for up to 97% efficiency. You can try these models using the LTC jigs.

These parts can actually produce one or two watts output.

You can get free samples direct from Linear and order small quantities. These parts cost about $2 to $3.

Paul

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I am looking at running a small motor

--
How much current does it need fully loaded?

JF

Can't you use a low voltage motor? This company has versions down to

1.5V nominal supply:

Ok, it's kind of the high end but if it has to be cheap there should be others. There are lots of low cost gizmos that run off a single battery, such as some of those water-spritz fans on a can. The amount of electronics in there is zilch.

--
Regards, Joerg

http://www.analogconsultants.com/

--
Indeed.

I\'ve used their stuff and it\'s absolutely gorgeous.

JF

It sure is. The other end of the price spectrum would be the $4.95 bottles with squirt lever and neoprene-blade fan. Some of those motors also runs on a single AA cell. When my wife bought one I scoffed but they really do work when it's north of 100F outside.

--
Regards, Joerg

http://www.analogconsultants.com/

Not around here, the humidity is too high.

Whatever happened to those "hobby motors" that were about a dime a dozen?

I have a schpritzer as well for the hot weather, and I've been known to freeze it before I go out - the ambient will start melting the ice as soon as you get it out, and it'll be ready to spray ice water in a few minutes. :-)

Cheers! Rich

The same that happened to the electronics store down the road: Gone. Nowadays kids get everything they want. They don't have to tinker and build stuff. So they don't.

Take the battery out first ;-)

--
Regards, Joerg

http://www.analogconsultants.com/

I needed hundreds of 1.5 V hobby motors for a Cub Scout Day Camp project in

2006. Found some at: , not exactly "dime a dozen" but I got them for ~$0.69. I notice that the price has now gone up.

Kelvin is a reasonable source for hobby parts for schools and kids.

Ken Fowler

price is up to $6.95/doz. or $5.95/2 doz.

--


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