On Thursday, December 20, 2012 5:39:33 PM UTC+2, Michael Terrell wrote:
> krw@att.bizzz wrote:
>
> >
>
> > Michael A. Terrell wrote:
>
> > >
>
> > >Sjouke Burry wrote:
> > > Or a switching regulator, so the engine can run at its most efficient
>
> > >speed?
>
> > Gee, that's a GREAT idea. Maybe you should tell the car manufacturers
>
> > about that. ;-)
>
> At one time there were variable rate automatic transmissions which
>
> did optimize the power curve but I haven't heard of one in decades.
Maybe not US manufacturers. But these are available with CVT.
HONDA JAZZ
Mercedes A & B class
Audi A4 - possibly other Audis
Reply by Michael A. Terrell●December 21, 20122012-12-21
Spehro Pefhany wrote:
>
> On Thu, 20 Dec 2012 10:39:33 -0500, the renowned "Michael A. Terrell"
> <mike.terrell@earthlink.net> wrote:
>
> >
> >krw@att.bizzz wrote:
> >>
> >> Michael A. Terrell wrote:
> >> >
> >> >Sjouke Burry wrote:
> >> >>
> >> >> Why not regulate the generator to output the correct charge voltage?
> >> >> No conversion losses, only slight modifications to the
> >> >> generator control hardware.
> >> >
> >> > Or a switching regulator, so the engine can run at its most efficient
> >> >speed?
> >>
> >> Gee, that's a GREAT idea. Maybe you should tell the car manufacturers
> >> about that. ;-)
> >
> >
> > Do you think the UAW would let them do anything to improve a vehicle
> >if they can't pad the production line with more of their people?
> >For instance: Back in the '70s Delco designed a car radio that could be
> >installed from the front of the dash with no tools. The UAW threw a
> >hissy fit, because it would cost a few union jobs.
> >
> >
> > At one time there were variable rate automatic transmissions which
> >did optimize the power curve but I haven't heard of one in decades.
>
> Nissan has been using Jatco CVTs in some of their models:
>
> http://www.jatco.co.jp/ENGLISH/products/
>
> I've driven a couple of them a fair bit, and they're pretty good.
> There have been some issues reported with reliability, but I've not
> seen it personally.
I stopped following new cars about 30 years ago. I'm glad they are
still working on them.
Reply by Spehro Pefhany●December 20, 20122012-12-20
On Thu, 20 Dec 2012 10:39:33 -0500, the renowned "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:
>
>krw@att.bizzz wrote:
>>
>> Michael A. Terrell wrote:
>> >
>> >Sjouke Burry wrote:
>> >>
>> >> Why not regulate the generator to output the correct charge voltage?
>> >> No conversion losses, only slight modifications to the
>> >> generator control hardware.
>> >
>> > Or a switching regulator, so the engine can run at its most efficient
>> >speed?
>>
>> Gee, that's a GREAT idea. Maybe you should tell the car manufacturers
>> about that. ;-)
>
>
> Do you think the UAW would let them do anything to improve a vehicle
>if they can't pad the production line with more of their people?
>For instance: Back in the '70s Delco designed a car radio that could be
>installed from the front of the dash with no tools. The UAW threw a
>hissy fit, because it would cost a few union jobs.
>
>
> At one time there were variable rate automatic transmissions which
>did optimize the power curve but I haven't heard of one in decades.
Nissan has been using Jatco CVTs in some of their models:
http://www.jatco.co.jp/ENGLISH/products/
I've driven a couple of them a fair bit, and they're pretty good.
There have been some issues reported with reliability, but I've not
seen it personally.
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
Reply by Michael A. Terrell●December 20, 20122012-12-20
linnix wrote:
>
> But can it be removed with no tools? If so, I would throw a fit as well. It would be open invitation for car thieves and broken windows.
No, it took a set of security tools to remove. Earlier radios were
easier to remove. pull off the knobs, remove two 3/8"/24 nuts and
you're done. It could be done in 30 seconds on some cars if you had a
hollow shaft Xcelite socket driver.
Ford was the worst for car radios. The idiots put the car radio on
the left side of the steering wheel at the same time they started using
TO-220 output transistors. They ignored the warning not to fan out the
leads at the transistor case, and they failed in droves. You had to
remove the steering column, then the entire dash to remove the radio.
It took about eight hours, if you knew exactly what to do. After the
first one, we insisted that the dealer pull the radio, and put up with
the owner nt having the car for at least two days.
Reply by Jasen Betts●December 20, 20122012-12-20
On 2012-12-21, John Larkin <jlarkin@highlandtechnology.com> wrote:
> Car/bike alternators are designed to be sort of constant-current
> devices, because that helps to drive the load over a wide range of
> RPMs.
All altenators, even ideal altenators, have an inherent current limit,
due to the field strength limit.
> As speed goes up, the open-circuit voltage goes up, but the w*L
> impedance goes up too, so things sort of cancel. The reason the load
> dump voltage is so high in a car is because the open-circuit voltage
> of the alternator is maybe 60 volts, to charge a 12 volt battery.
they behave like lossy current transformers.
> Anyhow, maybe the best regulator is a PWM'd mosfet short. The 50 amp
> switcher regulator inductors are free, namely the internal inductance
> of the alternator.
On Thu, 20 Dec 2012 10:39:33 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:
>
>krw@att.bizzz wrote:
>>
>> Michael A. Terrell wrote:
>> >
>> >Sjouke Burry wrote:
>> >>
>> >> Why not regulate the generator to output the correct charge voltage?
>> >> No conversion losses, only slight modifications to the
>> >> generator control hardware.
>> >
>> > Or a switching regulator, so the engine can run at its most efficient
>> >speed?
>>
>> Gee, that's a GREAT idea. Maybe you should tell the car manufacturers
>> about that. ;-)
>
>
> Do you think the UAW would let them do anything to improve a vehicle
>if they can't pad the production line with more of their people?
>For instance: Back in the '70s Delco designed a car radio that could be
>installed from the front of the dash with no tools. The UAW threw a
>hissy fit, because it would cost a few union jobs.
>
>
[snip]
One of my more stressful moments was during a tour of a GM alternator
manufacturing line in Anderson, IN (*)
There were union members PAID to stand around and watch the robots
make alternators, unaided by any human.
The intriguing step was watching the robot balance an armature... spin
it, magnetically watch its wobble... stop it exactly and drill away a
small amount of metal to balance it... repeat once, then perfectly
balanced.
(*) Night spot of Indiana... sit around the fire-pit in the lobby of
the Holiday Inn, and watch the snow fall ;-)
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Reply by Les Cargill●December 20, 20122012-12-20
Michael A. Terrell wrote:
>
<snip>
>
> Do you think the UAW would let them do anything to improve a vehicle
> if they can't pad the production line with more of their people?
> For instance: Back in the '70s Delco designed a car radio that could be
> installed from the front of the dash with no tools. The UAW threw a
> hissy fit, because it would cost a few union jobs.
>
>
> At one time there were variable rate automatic transmissions which
> did optimize the power curve but I haven't heard of one in decades.
>
Nissan offered a continuously variable transmission on the Murano.
--
Les Cargill
Reply by John Larkin●December 20, 20122012-12-20
On Thu, 20 Dec 2012 15:43:35 -0800 (PST), Mark <makolber@yahoo.com>
wrote:
>
>>
>> Alternator+rectifier types can be regulated by shorting their outputs, often
>> with an SCR. Shorting such a generator with PWM'd mosfets would be interesting.
>>
>> --
>>
>
>
>John,
>
>I know this is true for some alternators, because most motorcycle
>charging systems work this way, a simple shunt regulator at the
>output. But I've always wondered about this. My assumption is that
>this can work only if the output Z is pretty high. In a sense the
>alternator is always loaded at it's maximum current to keep the output
>voltage down. The question is WHY would anybody design it this way.
>Seems very wasteful of power and operating the alternator at max
>current 100% of the time can't be good for the life of the windings,
>in fact burnt out alternators is a common problem on some bikes. So
>again, WHY are the designed this way?
>
>Mark
Car/bike alternators are designed to be sort of constant-current
devices, because that helps to drive the load over a wide range of
RPMs. There is an air gap between the rotating field (wound or PM) and
the stator windings, effectively a lot of leakage inductance. If you
short it, the current is limited by the series inductance and it
doesn't (or isn't supposed to) get all that hot.
As speed goes up, the open-circuit voltage goes up, but the w*L
impedance goes up too, so things sort of cancel. The reason the load
dump voltage is so high in a car is because the open-circuit voltage
of the alternator is maybe 60 volts, to charge a 12 volt battery.
Anyhow, maybe the best regulator is a PWM'd mosfet short. The 50 amp
switcher regulator inductors are free, namely the internal inductance
of the alternator.
--
John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation
Reply by Mark●December 20, 20122012-12-20
>
> Alternator+rectifier types can be regulated by shorting their outputs, often
> with an SCR. Shorting such a generator with PWM'd mosfets would be interesting.
>
> --
>
John,
I know this is true for some alternators, because most motorcycle
charging systems work this way, a simple shunt regulator at the
output. But I've always wondered about this. My assumption is that
this can work only if the output Z is pretty high. In a sense the
alternator is always loaded at it's maximum current to keep the output
voltage down. The question is WHY would anybody design it this way.
Seems very wasteful of power and operating the alternator at max
current 100% of the time can't be good for the life of the windings,
in fact burnt out alternators is a common problem on some bikes. So
again, WHY are the designed this way?
Mark
Reply by Yzordderrex●December 20, 20122012-12-20
On Wednesday, December 19, 2012 9:52:53 PM UTC-5, Yzordderrex wrote:
> Greetings,
>=20
>=20
>=20
> I have a small diesel engine spinning a DC generator. I need a control c=
hip that will take approximately 60v that generator puts out and charge the=
lead acid bank. Bank is 16 27M Die Hard deep cycle wired in 4x4 configura=
tion. It is my intention to control diesel speed to give me a little headr=
oom for charging the battery pack. I will use external mosfets to get abou=
t 50A of charging current, so just looking for the control chip.
>=20
>=20
>=20
> Any ideas would be helpful.
>=20
>=20
>=20
> thanks,
>=20
> Bob
>=20
> N9NEO
I didn't want to get into too many details here - but you guys (being engin=
eers) leave me no choice:-) Thanks for all the design input, but I'm really=
all set. I'm just looking to do a 50 amp current source using a buck conv=
erter. I've been designing power conversion gear since the 70's. I find t=
he manufacturer search engines to be a little lacking, and Digikey not much=
better.
The generator I believe has permanent magnets on the stator with a wound ro=
tor and slip rings. (They sell em on Ebay for 4 or 5 hundred bucks. People=
use them as motors on motorcycles and lawn mowers and so forth.) I'm driv=
ing it with a Chinese diesel that is rated for 6HP. I have all set up, jus=
t have to buy the timing belt. I've geared it to run at the most efficient=
speed. I will eventually charge 32 batteries when fully up and running.
I am also doing 48vdc to 120vac converter/inverter, and PV array chargers. =
All this is being done in my spare time as I am General Contractor for my =
house that this is all going to power. Utility wanted $17k to string wires=
to my house. Roof going on today and windows next week. Hopeful to be in=
with some kind of electricity by the end of the year. Picked up 2kW worth=
of panels and the state and fed is going to kick in $2400 in rebates.
I am in-between jobs now so a little reluctant to call my usual TI or LT re=
ps. I've actually referred to this newsgroup as my design team on numerous=
occasions. I've been hanging around here for probably 10 years and gotten =
a lot of good design advice.
Thanks for all the design advice. Hope this tome has shed some light on p=
roject. Tim was the clear winner with supplying part numbers. Tim has bee=
n a very good ally over the years as well as John and some others. Thanks =
to all for the input - I'll be sure to follow up with my design. =20
MERRY CHRISTMAS
Bob
N9NEO