Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 129
Default 48 volt car elect not going to happen

The high(er) voltage car electrical system is not going to happen anytime
soon. The reasons, according to an article in Car and Driver are a) reliable
circuit protection hasn't been developed to the point where manufacturers
are 100% sure a loose wire or a short won't result in a shock or fire and b)
12 volts is an ideal voltage for headlight filaments- higher voltages
mandate thinner filaments which don't survive bumps and bangs very well.
Apparently GM was going to 48 volts for the 2006 model year, but backed off
mostly because of the circuit protection issue.

-Carl


  #2   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 144
Default 48 volt car elect not going to happen


"Carl Byrns" wrote in message
news:5l5pj.41034$K%.16220@trnddc04...
The high(er) voltage car electrical system is not going to happen anytime
soon. The reasons, according to an article in Car and Driver are a) reliable
circuit protection hasn't been developed to the point where manufacturers are
100% sure a loose wire or a short won't result in a shock or fire and


That suits me. Under the right conditions, 48 volts is plenty enough to
kill. Therefore, one inevitable result of 48 volt electrical systems in cars
will be the occasional dead mechanic. Would the advantages of higher voltage
systems be worth that result?

Vaughn


  #3   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 362
Default 48 volt car elect not going to happen

On Feb 2, 3:35 pm, "Vaughn Simon"
wrote:
"Carl Byrns" wrote in message

news:5l5pj.41034$K%.16220@trnddc04...

The high(er) voltage car electrical system is not going to happen anytime
soon. The reasons, according to an article in Car and Driver are a) reliable
circuit protection hasn't been developed to the point where manufacturers are
100% sure a loose wire or a short won't result in a shock or fire and


That suits me. Under the right conditions, 48 volts is plenty enough to
kill. Therefore, one inevitable result of 48 volt electrical systems in cars
will be the occasional dead mechanic. Would the advantages of higher voltage
systems be worth that result?

Vaughn


So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.

Paul
  #4   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 144
Default 48 volt car elect not going to happen



So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.


Yes, but that is "apples and oranges". (correct me if I am wrong) In a
hybrid car, most of the electrics are still 12 volt, the high voltage battery
just runs the hybrid part, and those wires are made very obvious.

The original post was about the potential conversion of ALL the electrics in
conventional cars to 48 volts.

Vaughn


  #5   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 18
Default 48 volt car elect not going to happen

On 2008-02-03, Vaughn Simon wrote:


So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.


Yes, but that is "apples and oranges". (correct me if I am wrong) In a
hybrid car, most of the electrics are still 12 volt, the high voltage battery
just runs the hybrid part, and those wires are made very obvious.


So, in an electric car, the starter is 12 volts?

i


  #6   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 5,154
Default 48 volt car elect not going to happen

On Sat, 02 Feb 2008 20:34:00 -0600, with neither quill nor qualm,
Ignoramus17662 quickly quoth:

On 2008-02-03, Vaughn Simon wrote:


So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.


Yes, but that is "apples and oranges". (correct me if I am wrong) In a
hybrid car, most of the electrics are still 12 volt, the high voltage battery
just runs the hybrid part, and those wires are made very obvious.


So, in an electric car, the starter is 12 volts?


I wonder how many cheeks you'll catch with that big hook, Ig.

---
The world is wide, and I will not waste my life in friction
when it could be turned into momentum.
--Frances Willard (1839 - 1898)
----------
  #7   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 18
Default 48 volt car elect not going to happen

On 2008-02-03, Larry Jaques novalidaddress@di wrote:
On Sat, 02 Feb 2008 20:34:00 -0600, with neither quill nor qualm,
Ignoramus17662 quickly quoth:

On 2008-02-03, Vaughn Simon wrote:


So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.

Yes, but that is "apples and oranges". (correct me if I am wrong) In a
hybrid car, most of the electrics are still 12 volt, the high voltage battery
just runs the hybrid part, and those wires are made very obvious.


So, in an electric car, the starter is 12 volts?


I wonder how many cheeks you'll catch with that big hook, Ig.


None so far, but I am waiting...

i
The world is wide, and I will not waste my life in friction
when it could be turned into momentum.

  #8   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 336
Default 48 volt car elect not going to happen

On Feb 2, 2:33�pm, "Carl Byrns" wrote:

Apparently GM was going to 48 volts for the 2006 model year, but backed off
mostly because of the circuit protection issue.

-Carl


Carl et all

The 48 volt figure is the nominal battery voltage, 4 X 12, closest to
52 volts which is the nominal voltage at which one gets shocked. IOW
the maximun safe voltage to work with before the voltage becomes a
shock hazard. There are of course exceptions to this. The kickback
from an inductance load can be many times the 12 volts that we
presently are accostomed to working with.

Also the 48 volt figure is not the maximun charging voltage when
charging a 48 volt system. eg the charging voltage for a 12 volt
system is 13.5 to 14.X something.

I read all this stuff perhaps 20 years ago when talk of higher voltage
Automobile Electric Systems was started. I don't remember the source
of the documentation. Probably a government publication.

Bob AZ
  #9   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 9
Default 48 volt car elect not going to happen



That suits me. Under the right conditions, 48 volts is plenty enough to
kill. Therefore, one inevitable result of 48 volt electrical systems in cars
will be the occasional dead mechanic.




How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.
  #10   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 18
Default 48 volt car elect not going to happen

On 2008-02-03, Bob AZ wrote:
The 48 volt figure is the nominal battery voltage, 4 X 12, closest to
52 volts which is the nominal voltage at which one gets shocked. IOW
the maximun safe voltage to work with before the voltage becomes a
shock hazard. There are of course exceptions to this. The kickback
from an inductance load can be many times the 12 volts that we
presently are accostomed to working with.

Also the 48 volt figure is not the maximun charging voltage when
charging a 48 volt system. eg the charging voltage for a 12 volt
system is 13.5 to 14.X something.

I read all this stuff perhaps 20 years ago when talk of higher voltage
Automobile Electric Systems was started. I don't remember the source
of the documentation. Probably a government publication.


Why are they not considering lower voltages, such as 24 nominal, which
is used in commercial trucks?

i


  #11   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,620
Default 48 volt car elect not going to happen

On Sat, 02 Feb 2008 20:34:00 -0600, Ignoramus17662 wrote:

On 2008-02-03, Vaughn Simon wrote:


So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.


Yes, but that is "apples and oranges". (correct me if I am wrong)
In a
hybrid car, most of the electrics are still 12 volt, the high voltage
battery just runs the hybrid part, and those wires are made very
obvious.


So, in an electric car, the starter is 12 volts?

i


I thought the electric cars were hand-cranked.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html
  #12   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 129
Default 48 volt car elect not going to happen


"Stephen Robinson" wrote in message
...


That suits me. Under the right conditions, 48 volts is plenty enough
to kill. Therefore, one inevitable result of 48 volt electrical systems
in cars will be the occasional dead mechanic.




How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.


Do you own an arc welder? Look at the open circuit voltage(should be on the
case somewhere). Now look at all the shock hazard warnings.

If you don't own an arc welder the open circuit voltage is usually around 48
volts and arc voltage is around 25 volts (sound familiar?) and at the right
amperage that is enough to kill you.

-Carl


  #13   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 680
Default 48 volt car elect not going to happen


"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT in
order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.

^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this. However, I have a couple
of reservations about your second sentence. The resistance of the body is
almost entirely in the skin, which is quite high when dry. If, somehow, you
got across some voltage while wet, or perhaps bleeding from an accident, the
resistance could be very much lower. Secondly, the amount of current that
can be lethal depends on the path through the body. The worst would be
across the shoulders, which places the heart in the circuit. The path from
one hand to the other, or from one hand to some lower part of the body could
also be quite dangerous.


  #14   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 18
Default 48 volt car elect not going to happen

On 2008-02-03, Stephen Robinson wrote:
Carl Byrns wrote:
"Stephen Robinson" wrote in message
...
That suits me. Under the right conditions, 48 volts is plenty enough
to kill. Therefore, one inevitable result of 48 volt electrical systems
in cars will be the occasional dead mechanic.


How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.


Do you own an arc welder? Look at the open circuit voltage(should be on the
case somewhere). Now look at all the shock hazard warnings.

If you don't own an arc welder the open circuit voltage is usually around 48
volts and arc voltage is around 25 volts (sound familiar?) and at the right
amperage that is enough to kill you.

-Carl


You need the VOLTAGE to to push the CURRENT in order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna
be enough.


Not the case if a wet human body is holding on to car frame, while
grabbing firmly some unlucky item energized to 48 volts. Resistance
depends mostly on how contact is done.
  #15   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 9
Default 48 volt car elect not going to happen

Carl Byrns wrote:
"Stephen Robinson" wrote in message
...
That suits me. Under the right conditions, 48 volts is plenty enough
to kill. Therefore, one inevitable result of 48 volt electrical systems
in cars will be the occasional dead mechanic.



How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.


Do you own an arc welder? Look at the open circuit voltage(should be on the
case somewhere). Now look at all the shock hazard warnings.

If you don't own an arc welder the open circuit voltage is usually around 48
volts and arc voltage is around 25 volts (sound familiar?) and at the right
amperage that is enough to kill you.

-Carl


You need the VOLTAGE to to push the CURRENT in order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna
be enough.


  #16   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 9
Default 48 volt car elect not going to happen

Leo Lichtman wrote:
"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT in
order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.

^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this. However, I have a couple
of reservations about your second sentence. The resistance of the body is
almost entirely in the skin, which is quite high when dry. If, somehow, you
got across some voltage while wet, or perhaps bleeding from an accident, the
resistance could be very much lower. Secondly, the amount of current that
can be lethal depends on the path through the body. The worst would be
across the shoulders, which places the heart in the circuit. The path from
one hand to the other, or from one hand to some lower part of the body could
also be quite dangerous.


Agreed, I still don't think 48 v is going to be very dangerous.
  #17   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,138
Default 48 volt car elect not going to happen

On Sun, 03 Feb 2008 05:26:20 GMT, "Carl Byrns"
wrote:


"Stephen Robinson" wrote in message
...


That suits me. Under the right conditions, 48 volts is plenty enough
to kill. Therefore, one inevitable result of 48 volt electrical systems
in cars will be the occasional dead mechanic.




How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.


Do you own an arc welder? Look at the open circuit voltage(should be on the
case somewhere). Now look at all the shock hazard warnings.

If you don't own an arc welder the open circuit voltage is usually around 48
volts and arc voltage is around 25 volts (sound familiar?) and at the right
amperage that is enough to kill you.

-Carl


The user handholds the live stinger of an arcwelder. BTW, the O.C.V
on many arcwelders is more like 60 to 80 volts.

Your house is wired with 110 volts, except for stove, dryer, A/C and
perhaps some stuff in the shop which is 220V hot-to-hot. In Europe
all domestic sockets are 240V.

The issue is cost of change. Some NEC wiring codes kick in at (I
think) around 48 volts so 36/42 volts sounds good for automotive.
Insulation is considerably cheaper and lighter than copper. Another
cost issue is switching and fault management of DC, which tends to
hold an arc at higher voltages. Fuses and contacts don't break
higher-voltage DC current well unless specifically designed to do
that. There's also the issue of the lightbulb mfrs worrying about
cost of moving to thinner, longer more fragile filaments.

These issues can and will be solved, eventually if not sooner. Silicon
in high volume keeps getting cheaper and more capable. When the cost
of not changing becomes higher to the mfr than cost of change, then
change will happen.
  #18   Report Post  
Posted to rec.crafts.metalworking
sk sk is offline
external usenet poster
 
Posts: 16
Default 48 volt car elect not going to happen

On Feb 3, 1:25 am, Don Foreman wrote:
On Sun, 03 Feb 2008 05:26:20 GMT, "Carl Byrns"



wrote:

"Stephen Robinson" wrote in message
...


That suits me. Under the right conditions, 48 volts is plenty enough
to kill. Therefore, one inevitable result of 48 volt electrical systems
in cars will be the occasional dead mechanic.


How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.


Do you own an arc welder? Look at the open circuit voltage(should be on the
case somewhere). Now look at all the shock hazard warnings.


If you don't own an arc welder the open circuit voltage is usually around 48
volts and arc voltage is around 25 volts (sound familiar?) and at the right
amperage that is enough to kill you.


-Carl


The user handholds the live stinger of an arcwelder. BTW, the O.C.V
on many arcwelders is more like 60 to 80 volts.

Your house is wired with 110 volts, except for stove, dryer, A/C and
perhaps some stuff in the shop which is 220V hot-to-hot. In Europe
all domestic sockets are 240V.

The issue is cost of change. Some NEC wiring codes kick in at (I
think) around 48 volts so 36/42 volts sounds good for automotive.
Insulation is considerably cheaper and lighter than copper. Another
cost issue is switching and fault management of DC, which tends to
hold an arc at higher voltages. Fuses and contacts don't break
higher-voltage DC current well unless specifically designed to do
that. There's also the issue of the lightbulb mfrs worrying about
cost of moving to thinner, longer more fragile filaments.

These issues can and will be solved, eventually if not sooner. Silicon
in high volume keeps getting cheaper and more capable. When the cost
of not changing becomes higher to the mfr than cost of change, then
change will happen.


The trip time of a "fast blow" MIL STD circuit breaker at 1000% over
current is specified around 880 milliseconds. You have to design the
current path for what may be a very low operating current for fault
current. Going from 12 v to 48 v will quadruple the fault current
keeping everything else the same (it's only the source and wire
resistance that limits this). When you use circuit boards to carry
this current, the circuit trace has to support this current until the
circuit breaker trips. Empirically we figured this to be 25AWG of
copper for a 28 volt aircraft DC system. What's interesting is if the
circuit trace "pops", the circuit breaker never does, and FR4 (fire
retardant PWB material) converts to carbon from this, and since ground
planes are used, this burnt trace makes a connection to ground. The
leakage current starts the board to glow orange where this occurs, and
emit smoke, and it burns like a firecracker fuse until all the board
carbon is converted to ash. The circuit breaker never trips as this
current is well under the 2-10 amp ratings.
ignator
  #19   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 366
Default 48 volt car elect not going to happen


"Stephen Robinson" wrote in message
...
Leo Lichtman wrote:
"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT
in order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna
be enough.

^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this. However, I have a
couple of reservations about your second sentence. The resistance of the
body is almost entirely in the skin, which is quite high when dry. If,
somehow, you got across some voltage while wet, or perhaps bleeding from
an accident, the resistance could be very much lower. Secondly, the
amount of current that can be lethal depends on the path through the
body. The worst would be across the shoulders, which places the heart in
the circuit. The path from one hand to the other, or from one hand to
some lower part of the body could also be quite dangerous.

Agreed, I still don't think 48 v is going to be very dangerous.


48 volts DC is not very dangerous. But because of the conditions car
mechanics work under, especially backyard mechanics, it could be contribute
to a more dangerous situation. I think we'll see a lot more off the cuff
"arc welding" of Craftsman adjustable wrenches.


  #20   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 129
Default 48 volt car elect not going to happen


"Don Foreman" wrote in message
...
On Sun, 03 Feb 2008 05:26:20 GMT, "Carl Byrns"
wrote:


"Stephen Robinson" wrote in message
...


That suits me. Under the right conditions, 48 volts is plenty
enough
to kill. Therefore, one inevitable result of 48 volt electrical
systems
in cars will be the occasional dead mechanic.



How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.


Do you own an arc welder? Look at the open circuit voltage(should be on
the
case somewhere). Now look at all the shock hazard warnings.

If you don't own an arc welder the open circuit voltage is usually around
48
volts and arc voltage is around 25 volts (sound familiar?) and at the
right
amperage that is enough to kill you.

-Carl


The user handholds the live stinger of an arcwelder. BTW, the O.C.V
on many arcwelders is more like 60 to 80 volts.


Not mine ( I checked) 48 and 25 are the numbers. The stinger _is_
insulated, no?

-Carl




  #21   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 129
Default 48 volt car elect not going to happen


"Stephen Robinson" wrote in message
...

You need the VOLTAGE to to push the CURRENT in order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.


I'll let you test that theory g. In the mean time, you might want to read
sk's post on aircraft (24v) circuits.

-Carl


  #22   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 5,154
Default 48 volt car elect not going to happen

On Sun, 03 Feb 2008 01:25:36 -0600, with neither quill nor qualm, Don
Foreman quickly quoth:

The user handholds the live stinger of an arcwelder. BTW, the O.C.V
on many arcwelders is more like 60 to 80 volts.

Your house is wired with 110 volts, except for stove, dryer, A/C and
perhaps some stuff in the shop which is 220V hot-to-hot. In Europe
all domestic sockets are 240V.


In many instances, contact with 240v will give you a quicker jolt so
you're more likely to jump away from contact with it. I know the
difference in feel and have worked with live circuits more often than
not. Nitrile gloves are good insulators, so pokes through them by the
wire ends let you know it's still hot. g


The issue is cost of change. Some NEC wiring codes kick in at (I
think) around 48 volts so 36/42 volts sounds good for automotive.
Insulation is considerably cheaper and lighter than copper. Another
cost issue is switching and fault management of DC, which tends to
hold an arc at higher voltages. Fuses and contacts don't break
higher-voltage DC current well unless specifically designed to do
that.


Yeah, arcing is bad news for switches. What's the voltage level at
which capacitors start helping with that, I wonder? I know they're
much more active on AC circuits.


There's also the issue of the lightbulb mfrs worrying about
cost of moving to thinner, longer more fragile filaments.


But with the trend toward all LED lighting, what's the worry? Very few
bulbs remain, such as headlamps, and those could be regulated or
transformed down to 12v pretty cheaply.


These issues can and will be solved, eventually if not sooner. Silicon
in high volume keeps getting cheaper and more capable. When the cost
of not changing becomes higher to the mfr than cost of change, then
change will happen.


--
I think this is the crux of the global warming media hype (not some of
the science). Gobal warming research and it's ugly step-sister, the
media, are a business. They will only feed frenzy that adds to their
business. Hence, the lack of talk about your cold and snowy western
weather, lack of hurricanes in '06, etc. The only things that will
be brought up are those that will "help" their cause and industry.
Do something for something we KNOW about, like the kid down the
street that needs a home, etc. Don't try to help for something
that we are trying (ridiculously) to predict will be a problem
100-200years from now!!
Thanks,

A Liberal, Environmentally Friendly, Global Warming, Anti-Hype Lad
James, 11Jan07 on Weather Channel's "One Degree" hype site
  #23   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 5,154
Default 48 volt car elect not going to happen

On Sun, 03 Feb 2008 13:32:48 GMT, with neither quill nor qualm, "Carl
Byrns" quickly quoth:

"Don Foreman" wrote in message
.. .


The user handholds the live stinger of an arcwelder. BTW, the O.C.V
on many arcwelders is more like 60 to 80 volts.


Not mine ( I checked) 48 and 25 are the numbers. The stinger _is_
insulated, no?


As are welding rods, and anyone above a halfwit wears gloves when
welding. Well, 'cept those in 3rd world countries using live 240v
3-phase xfmrs without goggles, long-sleeved pants, gloves, shoes, or
shirt. Remember that picture a few months ago? g

--
I think this is the crux of the global warming media hype (not some of
the science). Gobal warming research and it's ugly step-sister, the
media, are a business. They will only feed frenzy that adds to their
business. Hence, the lack of talk about your cold and snowy western
weather, lack of hurricanes in '06, etc. The only things that will
be brought up are those that will "help" their cause and industry.
Do something for something we KNOW about, like the kid down the
street that needs a home, etc. Don't try to help for something
that we are trying (ridiculously) to predict will be a problem
100-200years from now!!
Thanks,

A Liberal, Environmentally Friendly, Global Warming, Anti-Hype Lad
James, 11Jan07 on Weather Channel's "One Degree" hype site
  #24   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 17
Default 48 volt car elect not going to happen

Ignoramus17662 wrote:
On 2008-02-03, Vaughn Simon wrote:
So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.

Yes, but that is "apples and oranges". (correct me if I am wrong) In a
hybrid car, most of the electrics are still 12 volt, the high voltage battery
just runs the hybrid part, and those wires are made very obvious.


So, in an electric car, the starter is 12 volts?

i


We have a Honda Civic Hybrid and, best I can tell, the starter IS 12
volts, and is operated from the 12v battery. The kicker is that engine
always starts with the assist motor, which operates off the 156v
battery. The engine starts silently, I've never heard the starter
operate. I believe that the starter is for emergency use, that is, when
the assist system is not working.

Note that this system is quite a bit different from the Prelude.

--
Gary Brady
Austin, TX
www.powdercoatoven.4t.com
  #25   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 5
Default 48 volt car elect not going to happen

In article 5l5pj.41034$K%.16220@trnddc04, "Carl Byrns"
wrote:

The high(er) voltage car electrical system is not going to happen anytime
soon.

....SNIP...

Shucks, I'm sure going to miss that promised steering-wheel heater in my
next SUV.

grin

--
Paul S.
Remove Before Flight


  #26   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 43
Default 48 volt car elect not going to happen

On Feb 3, 12:09 am, "Leo Lichtman"
wrote:
"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT in

order to kill someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.


^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this. However, I have a couple
of reservations about your second sentence. The resistance of the body is
almost entirely in the skin, which is quite high when dry. If, somehow, you
got across some voltage while wet, or perhaps bleeding from an accident, the
resistance could be very much lower. Secondly, the amount of current that
can be lethal depends on the path through the body. The worst would be
across the shoulders, which places the heart in the circuit. The path from
one hand to the other, or from one hand to some lower part of the body could
also be quite dangerous.


Or, if the electrode you touch happens to have a sharp point or edge.
  #27   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 129
Default 48 volt car elect not going to happen


"Leo Lichtman" wrote in message
...

"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT in
order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.

^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this.


Apparently none of those people work at GM (the focus of the article). GM
backed off of 48 volts because of the reasons listed in the article, one of
which was shock hazard.

-Carl


  #28   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 32
Default 48 volt car elect not going to happen


"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT in
order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.

^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this. However, I have a couple
of reservations about your second sentence. The resistance of the body is
almost entirely in the skin, which is quite high when dry. If, somehow, you
got across some voltage while wet, or perhaps bleeding from an accident, the
resistance could be very much lower. Secondly, the amount of current that
can be lethal depends on the path through the body. The worst would be
across the shoulders, which places the heart in the circuit. The path from
one hand to the other, or from one hand to some lower part of the body could
also be quite dangerous.


I worked for the local cable company for over 18 years.... and at that
time, the plant was powered with 60Volt AC. We did all the splicing,
coring of the cable, etc., while AC was on and occasionally would get
a bite. Worst was while it was raining and everything was wet....
however, I understand the entire system is now powered with 90 Volt
AC. We never died.....
Ken.

  #29   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 4,562
Default 48 volt car elect not going to happen

Gary Brady wrote:

We have a Honda Civic Hybrid and, best I can tell, the starter IS 12
volts, and is operated from the 12v battery. The kicker is that engine
always starts with the assist motor, which operates off the 156v
battery. The engine starts silently, I've never heard the starter
operate. I believe that the starter is for emergency use, that is, when
the assist system is not working.



Or when you can't afford replacing drive batteries late in vehicles life
cycle? At least they were thinking.

Wes


  #30   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 4,562
Default 48 volt car elect not going to happen

"Leo Lichtman" wrote:


"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT in
order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.

^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this. However, I have a couple
of reservations about your second sentence. The resistance of the body is
almost entirely in the skin, which is quite high when dry. If, somehow, you
got across some voltage while wet, or perhaps bleeding from an accident, the
resistance could be very much lower. Secondly, the amount of current that
can be lethal depends on the path through the body. The worst would be
across the shoulders, which places the heart in the circuit. The path from
one hand to the other, or from one hand to some lower part of the body could
also be quite dangerous.


The worst burn I ever got was from a Honeywell Strobonar battery pack for a
flash unit. A huge 9.6 volts iirc. Unfortuantly, I had traces of
photodeveloping chemicals on my hands and the salts made my palm, in contact
with the power contacts very conductive. Instant steam burn. OUCH!

Wes


  #31   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 4,562
Default 48 volt car elect not going to happen

"Carl Byrns" wrote:

I'll let you test that theory g. In the mean time, you might want to read
sk's post on aircraft (24v) circuits.



24v bites too. I used to be a Phantom Phixer. F4-J / F4-S

Wes
  #32   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 144
Default 48 volt car elect not going to happen


Ken Sterling (Ken Sterling) wrote in message
...

I worked for the local cable company for over 18 years.... and at that
time, the plant was powered with 60Volt AC. We did all the splicing,
coring of the cable, etc., while AC was on and occasionally would get
a bite. Worst was while it was raining and everything was wet....
however, I understand the entire system is now powered with 90 Volt
AC. We never died.....


As an electrician, I have been zapped by 120 VAC and even 220 VAC more times
than I would like to admit. Fortunately, I am still alive. Unfortunately, that
does nothing to prove that shocks from 120 VAC and 220 VAC are not sometimes
lethal.

Vaughn


  #33   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 5,154
Default 48 volt car elect not going to happen

On Sun, 03 Feb 2008 14:53:56 -0500, with neither quill nor qualm, Wes
quickly quoth:

"Carl Byrns" wrote:

I'll let you test that theory g. In the mean time, you might want to read
sk's post on aircraft (24v) circuits.



24v bites too. I used to be a Phantom Phixer. F4-J / F4-S


So do fans and fan belts (and lathes, mills, saws, & grinders), but
you're careful when working around them, right?

"WTF is the difference?" he queried, innocently.

--
I think this is the crux of the global warming media hype (not some of
the science). Gobal warming research and it's ugly step-sister, the
media, are a business. They will only feed frenzy that adds to their
business. Hence, the lack of talk about your cold and snowy western
weather, lack of hurricanes in '06, etc. The only things that will
be brought up are those that will "help" their cause and industry.
Do something for something we KNOW about, like the kid down the
street that needs a home, etc. Don't try to help for something
that we are trying (ridiculously) to predict will be a problem
100-200years from now!!
Thanks,

A Liberal, Environmentally Friendly, Global Warming, Anti-Hype Lad
James, 11Jan07 on Weather Channel's "One Degree" hype site
  #34   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,384
Default 48 volt car elect not going to happen

Carl Byrns wrote:
The high(er) voltage car electrical system is not going to happen anytime
soon. The reasons, according to an article in Car and Driver are a) reliable
circuit protection hasn't been developed to the point where manufacturers
are 100% sure a loose wire or a short won't result in a shock or fire and b)
12 volts is an ideal voltage for headlight filaments- higher voltages
mandate thinner filaments which don't survive bumps and bangs very well.
Apparently GM was going to 48 volts for the 2006 model year, but backed off
mostly because of the circuit protection issue.

So sorry you are so far behind the times. The Prius has had a
300 V DC supply for about 9 (?) years, now. There are several
us-label cars with 42 V systems for their start/stop engines.

Cars with 12 V systems DEFINITELY have a history of electrical
fires, although they are fairly rare. I've seen one, but it had
a bunch of ham gear in it, so it was likely modifications not
the stock hardware that caused it.

I think a number of these systems have a small auxilliary
battery for the 12 V systems, so that that supply remains
available after a failure or accident trips the intertial cutoff
switch.

Jon
  #35   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,384
Default 48 volt car elect not going to happen

Ignoramus17662 wrote:
On 2008-02-03, Vaughn Simon wrote:

So, what voltage do the hybrid vehicles run at? I thought is was over
100, possibly 200 volts.


Yes, but that is "apples and oranges". (correct me if I am wrong) In a
hybrid car, most of the electrics are still 12 volt, the high voltage battery
just runs the hybrid part, and those wires are made very obvious.



So, in an electric car, the starter is 12 volts?

i

The Prius starts with the same motors as the traction system, so
it is 300 V. They have a really UNIQUE system with two motors
running on VFDs, connected by planetary gears with the engine.
So, they run power from one motor to the other through the VFDs
to perform the task of a transmission. The air conditioning
compressor is run by a smaller motor and VFD.

Jon


  #36   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,384
Default 48 volt car elect not going to happen

Stephen Robinson wrote:
You need the VOLTAGE to to push the CURRENT in order to kill
someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna
be enough.


Unless your hands are wet, or maybe your skin is pierced by a
few frayed strands of the wires. That really lowers your
resistance.

Jon
  #37   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 1,384
Default 48 volt car elect not going to happen

Leo Lichtman wrote:
"Stephen Robinson" wrote: You need the VOLTAGE to to push the CURRENT in
order to kill

someone(approx 30 mA).The human body is a very high resistance object,
which needs very high voltage to provide that current. 48v ain't gonna be
enough.


^^^^^^^^^^^^^^^^^^^^^^^
It is refreshing that SOMEONE seems to know this. However, I have a couple
of reservations about your second sentence. The resistance of the body is
almost entirely in the skin, which is quite high when dry. If, somehow, you
got across some voltage while wet, or perhaps bleeding from an accident, the
resistance could be very much lower. Secondly, the amount of current that
can be lethal depends on the path through the body. The worst would be
across the shoulders, which places the heart in the circuit. The path from
one hand to the other, or from one hand to some lower part of the body could
also be quite dangerous.



Actually either arm to the opposite leg is supposed to be the
worst. I've gotten some shocks that get into the letal level,
but it just happened to hit my muscles in the way that threw me
off the circuit instead of the opposite. The worst is the
condition of being "tetanized" where your muscles lock you on
the circuit, and it can actually be very hard for insulated
persons to knok you free with a hot stick or similar tool.
One guy at work was using a bad hot stick, and got tetanized
while flipping a 4160 V switch and his safety watcher had to
beat the CRAP out of him to break the connection.

(I don't work on this high tension stuff, but electronics, but I
am aware of the hazards.)

Jon
  #38   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 580
Default 48 volt car elect not going to happen

In article
,
"Vaughn Simon" wrote:

Ken Sterling (Ken Sterling) wrote in message
...

I worked for the local cable company for over 18 years.... and at that
time, the plant was powered with 60Volt AC. We did all the splicing,
coring of the cable, etc., while AC was on and occasionally would get
a bite. Worst was while it was raining and everything was wet....
however, I understand the entire system is now powered with 90 Volt
AC. We never died.....


As an electrician, I have been zapped by 120 VAC and even 220 VAC more
times
than I would like to admit. Fortunately, I am still alive. Unfortunately,
that
does nothing to prove that shocks from 120 VAC and 220 VAC are not sometimes
lethal.


I've been zapped with 250,000 volts and lived (low current

Free men own guns - www(dot)geocities(dot)com/CapitolHill/5357/
  #39   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 3,138
Default 48 volt car elect not going to happen

On Sun, 3 Feb 2008 02:00:34 -0800 (PST), sk
wrote:

On Feb 3, 1:25 am, Don Foreman wrote:
On Sun, 03 Feb 2008 05:26:20 GMT, "Carl Byrns"



wrote:

"Stephen Robinson" wrote in message
...


That suits me. Under the right conditions, 48 volts is plenty enough
to kill. Therefore, one inevitable result of 48 volt electrical systems
in cars will be the occasional dead mechanic.


How will 48v kill people, except for causing a fire, which 12 v is quite
capable of doing that also.


Do you own an arc welder? Look at the open circuit voltage(should be on the
case somewhere). Now look at all the shock hazard warnings.


If you don't own an arc welder the open circuit voltage is usually around 48
volts and arc voltage is around 25 volts (sound familiar?) and at the right
amperage that is enough to kill you.


-Carl


The user handholds the live stinger of an arcwelder. BTW, the O.C.V
on many arcwelders is more like 60 to 80 volts.

Your house is wired with 110 volts, except for stove, dryer, A/C and
perhaps some stuff in the shop which is 220V hot-to-hot. In Europe
all domestic sockets are 240V.

The issue is cost of change. Some NEC wiring codes kick in at (I
think) around 48 volts so 36/42 volts sounds good for automotive.
Insulation is considerably cheaper and lighter than copper. Another
cost issue is switching and fault management of DC, which tends to
hold an arc at higher voltages. Fuses and contacts don't break
higher-voltage DC current well unless specifically designed to do
that. There's also the issue of the lightbulb mfrs worrying about
cost of moving to thinner, longer more fragile filaments.

These issues can and will be solved, eventually if not sooner. Silicon
in high volume keeps getting cheaper and more capable. When the cost
of not changing becomes higher to the mfr than cost of change, then
change will happen.


The trip time of a "fast blow" MIL STD circuit breaker at 1000% over
current is specified around 880 milliseconds. You have to design the
current path for what may be a very low operating current for fault
current. Going from 12 v to 48 v will quadruple the fault current
keeping everything else the same (it's only the source and wire
resistance that limits this). When you use circuit boards to carry
this current, the circuit trace has to support this current until the
circuit breaker trips. Empirically we figured this to be 25AWG of
copper for a 28 volt aircraft DC system. What's interesting is if the
circuit trace "pops", the circuit breaker never does, and FR4 (fire
retardant PWB material) converts to carbon from this, and since ground
planes are used, this burnt trace makes a connection to ground. The
leakage current starts the board to glow orange where this occurs, and
emit smoke, and it burns like a firecracker fuse until all the board
carbon is converted to ash. The circuit breaker never trips as this
current is well under the 2-10 amp ratings.
ignator


I don't minimize the issues. I merely think that if existing
solutions don't suffice, better solutions will be found if/when
motivation is sufficient to develop them.
  #40   Report Post  
Posted to rec.crafts.metalworking
external usenet poster
 
Posts: 5,154
Default 48 volt car elect not going to happen

On Sun, 03 Feb 2008 15:41:11 -0600, with neither quill nor qualm, nick
hull quickly quoth:

In article
,
"Vaughn Simon" wrote:

Ken Sterling (Ken Sterling) wrote in message
...

I worked for the local cable company for over 18 years.... and at that
time, the plant was powered with 60Volt AC. We did all the splicing,
coring of the cable, etc., while AC was on and occasionally would get
a bite. Worst was while it was raining and everything was wet....
however, I understand the entire system is now powered with 90 Volt
AC. We never died.....


As an electrician, I have been zapped by 120 VAC and even 220 VAC more
times
than I would like to admit. Fortunately, I am still alive. Unfortunately,
that
does nothing to prove that shocks from 120 VAC and 220 VAC are not sometimes
lethal.


I've been zapped with 250,000 volts and lived (low current


Were you on all fours and running with the rest of the herd at the
time? gd&r

--
Our greatest glory is not in never falling, but in getting up every time we do.
-- Confucius
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
18 volt battery in 12 volt drill? [email protected] Home Repair 39 November 28th 20 11:30 PM
Heads up on 1 day sale. Dewalt 18 volt drill, 7.2 volt driver, charger and case $133.00 Free shipping from Home Depot. Leon Woodworking 5 December 6th 05 02:42 AM
Connecting a 110 Volt 300 watt generator to a 220 Volt panel [email protected] Home Repair 23 November 24th 05 09:37 PM
Run a 9.6 volt Makita drill off 12 volt car battery - voltatage dropping resistor ? [email protected] Electronics Repair 10 January 3rd 05 05:13 AM
Can you derive a 110 volt outlet from a 4 wire 220 volt in the US? Steven Kingsley Home Repair 30 August 1st 03 07:34 AM


All times are GMT +1. The time now is 09:26 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"