[time-nuts] OT: Re: Where does 28V come from?
dave at uk-ar.co.uk
Wed Jul 22 13:37:48 UTC 2009
The other stumbling block is that the EMI emissions from 36(or more)
volt systems are sufficiently greater, that passing EMC tests is more a
problem, just because of the extra voltage and the resulting transients
produced. Some switchgear was also found to be wanting, not in
insulation, but the extra arcing is a problem reducing the contact life.
In any case, most car makers are now going towards 12V bus systems,
where one high(ish) current feed goes round the whole vehicle body, with
either superimposed data, or a separate data bus to control all the
lights, doors, windows, HVAC, accessories etc etc. With a corresponding
weight and cost saving.
Accessories are also becoming lower powered and more efficient, reducing
the need for power, though you wouldn't know it from some of the sound
systems the kids fit these days!
If you want High Voltage vehicle electrics in a current production car,
look at the (in)famous Prius. 440V 3 phase AC for the traction motor,
fed from 200+V batteries! (Not so worried about 50 Volts now?)
You could quite literally run a house of the car when you park up, and
when the battery gets low, arrange for the engine to automatically start
to re-charge it, unless like some you've hooked up an array of solar
cells... http://aprs.org/APRS-SPHEV.html for example. Your own
personal mobile UPS! (Have to say, some of the modifications you have
to wonder about!)
Me.... Having none of that, way too difficult and expensive to
maintain, but I admire the ingenuity of it all...
Regards to All..
> -----Original Message-----
> 2. Re: Where does 28V come from? (Robert Atkinson)
> 3. Re: Where does 28V come from? (Poul-Henning Kamp)
> 4. Re: Where does 28V come from? (Lux, James P (337C))
> 5. Re: Where does 28V come from? (Poul-Henning Kamp)
> 7. Re: Where does 28V come from? (Magnus Danielson)
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