From: Roger Johansson
Subject: Re: Reducing contact resistance for low volt use?
Date: Thu, 12 Dec 2002 04:25:08 +0100
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jmuchow@SPAMMENOTcamlight.com (John Muchow) wrote:
>>>>The power supply would compensate for both the shunt and the rest of
>>>>the outer circuit.
>So, the external power supply would have a voltage equaling whatever
>is needed to compensate whatever is lost through
>wire/connections/contacts...perhaps 0.3V at 100+ amps? And the cell
>being discharged would be in series with the power supply?
Yes, to both questions.
Let's wait for the real engineers to wake up and think about it, they
might find out how to do it. :-)
Maybe if we put our head together we can solve this.
If we see it as three devices in series, battery, a shunt, a power
supply. The voltage over the shunt is amplified and used to control
the power supply.
It is set so that the power supply is giving a voltage which is enough
to push the current through the power supply plus the shunt.
Assume the current is X to begin with (or zero).
This gives a zero voltage over the shunt.
The battery raises this to another value when it is connected and the
series circuit is completed.
The power supply compensates that increase, so the outer resistance is
This allows the battery to raise the current a little more.
That is compensated too.
Until the current has become what the battery is capable of pushing
through itself, with an outer circuit which is effectively a zero
resistance, or some other low value of our choice.
Hmmm.. sorry, my brain is out of steam here, but maybe someone else
can build further on the line of thought, or something similar.
As you said, others have touched the idea already.