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Re: volts and amps



At 10:27 7/14/00 -0500, Doug C wrote:
...
If a device is "designed for 4.5 V", to me that says its internal
resistance is much higher than that of the intended voltage source and
that voltage will normally dictate the current as a dependent parameter,
not as an independent parameter.

\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/

Doug Craigen
http://www.dctech.com/physics/


John D mentioned an exceptional case earlier -
the car headlamp on the dry cell supply.

Here are one or two more:
The starter motor used on 12 volt cars will likely burn out if
driven with a stiff 12 volt supply.
The coil on some older cars (Fords in particular) would also burn out
if their dropper resistor were somehow shorted for long
(for imagined spark boosting?).

There is a move to 42Volt auto systems, in progress now.
This is happening for much the same reason cars moved to 12V
from 6 V systems mid century.




brian whatcott <inet@intellisys.net> Altus OK
Eureka!