how to power a single D 1.5V cell temporarily without a battery?

What's crazy about not wanting to spend $400+ for an ultra simple circuit?

Yep, for $400+, something that costs probably $10 to make.

True, but try finding one at a reasonable price.

OK

Survivalist nutjob?

Poor guy......

..... Phil

Goodbye Phil. If you can't respond in kind, then I'll no longer see or respond accordingly. I didn't see you offering any type of help other than bs anyway so take care....

I don't think that's fair, you don't know me and I know nothing about you. Unless you can actually help here, please keep derogatory comments

to yourself and I'll thank you in advance.....

By the way, if you and Phil think there's nothing wrong with this world the way it is now, then you are not living on planet earth.

=================

..... Phil

Many of us are old enough to remember the 1950s and early 1960s, when civil defense responses to the threat of nuclear war were at the front of everybody's mind. (I'm a bit younger than that myself, but my older siblings were trained in duck-and-cover.)

That went away when the Soviet Union detonated their first hydrogen bomb--not because we were any safer, but because civil defense precautions are powerless to help against H-bombs.

Asymmetric threats such as the norks and the Iranians aren't in that league just yet, so civil defense measures are still possible against them.

Cheers

Phil Hobbs

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Perhaps a pair of lemons battery (around 1.8VDC) if you are trying to get simple. Not a lot of current though.

This is indeed another way, but it is still a battery, all be it a home made, emergency, one...

Solar cell, Johnson thermoelectric cell, or perhaps "The Martian" RPG plutonium generator? Not sure if those are available surplus yet.

John :-#)#

Methinks that if you can get power from nothing like you mention, you can then make a perpetual power generator. Not going to happen.

So, what you need for the electrometer:

- relatively stable DC adjustable from 0 to 300 V at max 60 uA - small light to read the fiber position

Most of the energy consumption in the original constructs goes to the incandescent lamp used as the light. In a modern construction, it could be replaced by a high-efficiency LED run at small current.

A direct hand-crank feed has the problem of widely varying voltage along with the cranking speed. There has to be a kind of buffer to even out the fluctuations, or you do not succeed in getting the hair into the correct charged position. The idea of a rechargeable battery buffering the feed seems the simplest to me.

That is essentially a cheap and cheerful mains powered DC 300v supply across a potentiometer. Nothing special there at all. You don't need high current to charge up a dosimeter only an adjustable voltage.

Your best bet for a near equivalent would be one of the cheap emergency light inverters which could probably be subverted to work off a 12v car battery with relative ease. I'm assuming that you don't do electronics from the context and the weird title you have given this thread.

Your simplest option is a rechargeable D-cell and a solar powered or hand cranked dynamo charger iff you must be entirely off grid.

To power something for a few minutes that expects a D cell you can get away with an AA cell suitably padded to sit in the middle of the available space. Some cheap and nasty rechargeable D cells are exactly that. An AA cell can source nearly 10A at a pinch but gets rather warm.

Perhaps if you explained why you wanted to not use a D cell battery powered unit it would help us understand what you really do want.