42v to replace 12v
Submitted: Monday, Nov 08, 2004 at 15:34
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Mark
Interesting article on the future of vehicle electrics. No more running jumper cable diameter cables to the fridge outlet !!
"One benefit of increasing the voltage to 42V is a reduction in wiring gauges. A current mid-size car has a wiring loom that weighs 35kg or more and contains 2km of wire, 1000 cut leads and 300 connectors. With the potential for loads of many kilowatts (the catalytic converter heating in the BMW 750iL requires a short-term power of 17kW!), the current flow required at 13.8V becomes very high indeed. As a result, conductor sizes are large, adding cost and weight. Increasing the voltage reduces the current flow and so smaller conductors can be used".
Full story
http://www.siliconchip.com.au/
Reply By: Lone Wolf - Monday, Nov 08, 2004 at 16:52
Monday, Nov 08, 2004 at 16:52
Mark, I remember reading this over a year ago, and if my memory serves me correct, 42 volt was still not decided upon internationally. It seems the way to go, after all, we did start out with 6 volts, and now our trucks are running 24 volt, and some of the "B" Doubles are experiencing voltage drop at the rear end of the last trailer.
I would assume, that if this becomes the norm, there will still be 12 volt bus on the system somewhere.
Someone out there may correct me, but is Air Craft electronics like REALLY high, so they can use thinner cabling?
Cheers
Wolfie
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Follow Up By: ToyMotor - Monday, Nov 08, 2004 at 18:59
Monday, Nov 08, 2004 at 18:59
Wolfie wrote:
Someone out there may correct me, but is Air Craft electronics like REALLY high, so they can use thinner cabling?
Well I wouldn't think of correcting you for asking a question! In my experience, standard aircraft systems use 115V 400Hz AC, and 28V DC. However, aircraft electronics is "like really high" for at least some of the time, sometimes above 35,000 feet. ;-)
Cheers
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342497
Reply By: GaryInOz (Vic) - Monday, Nov 08, 2004 at 19:15
Monday, Nov 08, 2004 at 19:15
"42 Volt" is actually 36 volt under charge, much the same way as our 12 volt car batteries are charged at 14 or so volts, so before the question is asked it wont be 3 1/2 batteries worth...
Standard aircraft electricals are 28 volt (=24 volt battery).
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83539
Reply By: AndrewX - Monday, Nov 08, 2004 at 23:40
Monday, Nov 08, 2004 at 23:40
Or it could be a 21 cell battery! I think most countries run diesel 4wds on 24 volts by the way.
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83593
Reply By: Member - Hugh (WA) - Tuesday, Nov 09, 2004 at 01:09
Tuesday, Nov 09, 2004 at 01:09
Hi Mark,
A colleague of
mine at work is contributing to work in this area with SAE working group. Attached link to 42V
frequently asked questions will hopefully provide more insight to the topic.
SAE 42V FAQ
Regards,
Hugh
AnswerID:
83604