[clug] Exercise and pay the bills!
Neil Pickford
neilp at goldweb.com.au
Mon Feb 9 21:50:04 GMT 2009
May I suggest a Truck Alternator 24V.
You can also get alternator stators rewound.
Uncontrolled (without a properly working regulator) alternators can
produce over a hundred volts so I would suggest a truck alternator with
a regulator modified to control output at 48-52 volts.
A vehicle alternator is a 3 phase alternating current machine with 3
windings on the stator each with a set of 6 big diodes to rectify the
output to a common DC output Bus. By using a Truck alternator you will
get higher voltage capability diodes which would be more suitable for
the task. As stated earlier any alternator would easily absorb the
energy that a human could produce.
The regulator supplies current to the rotor electromagnet via slip
rings. The stronger the current in the rotor the higher the Electro
Motive Force (EMF = Voltage) induced in the stator windings. This is why
full voltage on the rotor (due to a regulator fault) can produce
hundreds of volts. I had a mate who had the problem in his car (battery
lead fell off causing the regulator to loose it's reference [poor
design]) and all the electrical components fried and caught fire as he
was driving along.
Generally the regulator gets its operating voltage from a central star
point in the stator windings which is approximately 1/3 of the output
voltage but you do need a voltage source (battery to get things going in
a nice stable way).
Neil Pickford.
Sam Couter wrote:
> Robert Edwards <bob at cs.anu.edu.au> wrote:
>> A (smallish) car alternator (ie. 13.8V) and a 12V-48V inverter might be
>> the best bet to get 48V into your power feed-in.
>
> This discussion drifted in all sorts of amusing and off-topic
> directions, but I just wanted to come back to this bit.
>
> A car alternator usually produces close to 15 volts if the regulator is
> still working correctly. A lead-acid battery is nominally 12V but really
> produces 13.8 and the alternator needs to charge that, not just meet it.
> So it's a little higher. I don't know how easy it would be to just
> replace the regulator with your own to make the alternator output 48V
> instead of messing with a 12V-48V converter before the 48V-240V
> inverter.
>
> Also, the smallest car alternator you're likely to find can probably
> handle at least 300W or so output, which is more than you'll be producing
> on an exercise cycle unless you're a metabolic freak like Lance Armstrong.
> So I don't think you need to worry about getting one that's big enough,
> any will do.
>
More information about the linux
mailing list