EV Digest 6791
Topics covered in this issue include:
1) Re: Power Stering and A/C
by "Roland Wiench" <[EMAIL PROTECTED]>
2) Re: Using Audio Capacitors for Dragsters
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Power Stering and A/C
by "Roland Wiench" <[EMAIL PROTECTED]>
4) Re: Reality check, Re: Permanent magnet motor question
by Frank John <[EMAIL PROTECTED]>
5) RE: SepEx Regen Chopper - Help!
by "Dale Ulan" <[EMAIL PROTECTED]>
6) Re: Forklift RPM
by Jim Husted <[EMAIL PROTECTED]>
7) Semi-electronic controllers?
by Tom Gocze <[EMAIL PROTECTED]>
8) Last minute Power of DC Info #1
by Chip Gribben <[EMAIL PROTECTED]>
9) RE: direct drive or transmission?
by "Roger Stockton" <[EMAIL PROTECTED]>
10) Calling Rich Rudman
by Jim Dempsey <[EMAIL PROTECTED]>
11) RE: direct drive or transmission?
by "damon henry" <[EMAIL PROTECTED]>
12) Re: Semi-electronic controllers?
by Jack Murray <[EMAIL PROTECTED]>
13) Series motor regen with CC? and Semi-electronic controllers?
by "jerryd" <[EMAIL PROTECTED]>
14) Re: Last minute Power of DC Info #1
by Jim Husted <[EMAIL PROTECTED]>
15) RE: direct drive or transmission?
by MIKE WILLMON <[EMAIL PROTECTED]>
16) Re: Semi-electronic controllers?
by "jerryd" <[EMAIL PROTECTED]>
17) Evlist public Calender and ev mailed faq needed
by GWMobile <[EMAIL PROTECTED]>
18) RE: direct drive or transmission?
by "Roger Stockton" <[EMAIL PROTECTED]>
--- Begin Message ---
Hello Ed,
Did not have to build it. The inverter-alternator is a large 3 phase Delco
alternator which is design for a Dynamote inverter. This alternator has 7
terminals on it, which is a + field, - field, trio, positive power, negative
power, a excitation circuit, and a regulator control circuit.
All this is wired to the Dynamote inverter, which produces true 120 VAC 60
Hz at 6000 watts. The alternator-inverter input voltage to the inverter, is
110 VDC at 7 kw.
This inverter also have a 12-15 vdc output for charging a battery and
provides 12 volt power.
This is a large unit, normally use for 120 VAC power for ships and large
utility trucks. This unit cost about $2500.00 back in 1977. I replace the
inverter section of this unit with a smaller solid state unit which is still
16 inches long and 8 inches by 10 inches square.
I normally pull about 20 amps in the summer and I can load it up to about 40
to 50 amps by turning on three heating units, two AC pumps, five fans, and
over 30 lights which I may turn on during a coast down on a icy hill or
assist the EV in driving very slipply icy roads.
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 18, 2007 10:38 AM
Subject: Re: Power Stering and A/C
> Roland -
> How did you build the alternator-inverter for regen of a 120v pack?
>
> (I'd like to recharge a 144v pack)
> How did you keep the alternator (and everthing else) from overheating on
> 'long downhill runs' (not that there's any around here, but you never know
> where I might go...)
>
> What did you use to provide the electric clutch off the pilot shaft - an
> old AC compressor clutch, or something else?
> Did you keep a log?
> Can we see it?
>
> Thanks!!
>
> Ed Cooley
> Charlotte, NC
>
>
>
>
>
> "Roland Wiench" <[EMAIL PROTECTED]>
> Sent by: [EMAIL PROTECTED]
> 05/18/2007 12:15
> Please respond to
> ev@listproc.sjsu.edu
>
>
> To
> <ev@listproc.sjsu.edu>
> cc
>
> Subject
> Re: Power Stering and A/C
>
>
>
>
>
>
> Hello Guy,
>
> Yes, I have all that and more. See
> http://www.austinev.org/evalbum/470.html
>
> These pictures were taken back in 2002. The last mod was done in 2000.
> Since then I added three electric drives for the accessories, a EVCan
> electric power steering unit, a back up electric clutch that comes off the
>
> pilot shaft of the motor to provide backup power to the accessory drive in
>
> case the drive motors or the DC-DC converters go out and provides
> accessory
> REGEN while the drive motors are off line.
>
> A hot water electric heating system was added, Zilla and Zilla water cool
> fill tank, a PFC-50 charger that raise out of back compartment on gas
> struts, two more contactors, chassis boxes, more switches and instruments.
>
> So you can barely see the components in this EV now.
>
> I mounted the A/C unit, as well as a inverter-alternator, a vacuum pump
> and
> two 3 hp drive motors a GMC accessory aluminum mounting plate that is
> normally install on the front of a diesel engine. It has all the bracket
> mounts to hold all the accessories including a GMC vacuum pump.
>
> I mounted this accessory plate onto a large 1/2 inch thick aluminum plate
> that is bolted to a 4 in. x 4 in. by 3/8 aluminum angle at the bottom
> which
> is bolted down to the frame with two engine donuts mounts. Another
> support
> plate is mounted 4 inches behind this which is only a foot high, and all
> is
> bolt down to the frame in like manner.
>
> The motor pilot shaft has a Dodge Dynaflex coupler on it is connected to a
>
> drive shaft through two face mounted bearings on the two mounting plates.
> This drive shaft is in the save position that a engine damper wheel and
> pulley would be at.
>
> You do not need a damper wheel, but I use the same diameter pulleys on all
>
> the accessories as it would be on a engine. The pulleys I use are
> industrial solid steel type, not the stamp sheet metal type. You could
> also
> use a serpentine belt kit also.
>
> I am do a mod now, while I remove the Dynaflex coupler and install a
> electric clutch which will disconnect the motor from the accessory drive
> unit when the accessory motors go off line, during a coast down long
> hills.
> This provides safety for me, so the EV does not run away going down long
> hills in the winter on icy hills. During this time, the
> alternator-inverter
> provides 120 VAC 60 cycle 6kw to the on board battery charger, to provide
> some REGEN to the batteries.
>
> Roland
>
>
>
>
> ----- Original Message -----
> From: "Guy Stockwell" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Friday, May 18, 2007 9:19 AM
> Subject: Power Stering and A/C
>
>
> > I'm new the the list and am ready to pull the trigger on a conversion,
> but
> > was wondering if anyone has incorporated power steering and A/C as part
> of
> > their conversion.
> >
> > Thanks in advance!
> >
> > Guy
> >
> >
>
>
>
--- End Message ---
--- Begin Message ---
Marty Hewes wrote:
That would be a very cool controller. Imagine being able to have 2 72
volt strings of 6 volt GC batteries in parallel to provide lotsa
acceleration current without damaging the batteries, and then having the
controller be able to boost the voltage for higher speeds. I suppose
someone here has done a setup that does series parallel switching of
battery strings to achieve this?
The 1974 International Rectifier SCR Applications Handbook describes a
controller of this type. They ran a standard 72v series traction motor
from a single 12v battery. An SCR controller was used, configured as a
boost converter. The motor's field winding was the boost inductor. The
capacitors normally present at the controller input were across the
motor armature. As a result, input ripple current was high, but motor
ripple current was very low.
The efficiency was low (about 70%) because the SCR's 1.5v drop and the
freewheel diode's 1v drop were over 20% of the supply voltage. But it
happily converted 12v at 100a into 72v at 12a. Interestingly, the series
motor behaved almost exactly the same as it would with a conventional
72v pack and buck converter style controller. But since you could boost
the motor voltage considerably above pack voltage, it allowed higher
torques at higher speeds than a conventional controller.
Such a controller might be promising with today's low drop MOSFETs and
schottky diodes.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Hello Guy,
I using 30 each 260 AH Trojan 6 volt batteries with a standard post plus a
threaded stud coming out the top. The battery post is install on a offset
connector link. I than install the battery clamp all the way down around
the post so the base of the connector is pressing against the base.
I tighten up the battery clamp with a in.lb. insulated torque wrench (slip
some foam pipe insulation around the handles) to 75 inch lbs. The battery
clamp is a little down from the top of the post, so I made lead washers from
pure lead from 1/4 inch rolls you can get at a fishing equipment store.
Install the lead washer on top of the battery clamp so it extends a little
bit above the battery post. Now, install a stainless steel washer, lock
washer, and nut and torque that to 75 inch lbs. The head of the bolt inside
the post puts addition side force against the battery clamp as well downward
force on the base of the connector link.
I found that using only a battery clamp only. the shrink back of the post
will loss about 5 in. lbs. in the first 5 miles. You then should recheck the
torque again in the next 10 miles until you may only loss less than 1 in.lb.
Adding the addition down and side force of the battery connector, this
shrink back of the lead post is reduce.
Installing a top washer, also prevents the post from mushrooming out the top
of a battery connector.
Roland
----- Original Message -----
From: "Guy Stockwell" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, May 18, 2007 12:14 PM
Subject: RE: Power Stering and A/C
> Thanks Roland,
>
> I am looking at converting a mid 90's BMW 3 series and would definitely
> like
> to have it as an all weather driver. My average daily round trip commute
> is
> about 25 miles on a relatively flat grade (Lexington, Ky). What type of
> batteries do you use 6v, 12v, 8v?
>
> Guy
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Roland Wiench
> Sent: Friday, May 18, 2007 2:02 PM
> To: ev@listproc.sjsu.edu
> Subject: Re: Power Stering and A/C
>
> If you are going to run a full size EV with everything you want on it so
> you
>
> can run it all year around in any temperature, in the rain, high wind, any
> snow depth, on ice, up and down steep hills, then just install a higher
> voltage and ampere hour batteries. I have about the same range or even
> more
>
> than some lighter EV's with nothing on it even though I draw more battery
> amp.
>
> A friend of mind that lives down the street from me, has a VW Bug EV that
> is
>
> strip down like a dune buggy. Does not run it in the winter, while it is
> raining, and does not coast good down hills and does not have the range as
> my EV has.
>
> I am running 260 ah batteries, and my range would be 81.25 miles if I took
> the batteries to 90% D0D. I normally charge at 30% DOD which is about 25
> miles.
>
> Roland
>
>
>
>
> ----- Original Message -----
> From: "Guy Stockwell" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Friday, May 18, 2007 11:04 AM
> Subject: RE: Power Stering and A/C
>
>
> >
> >
> > I appreciate the responses! What kind of impact have you seen on the
> > range
> > with A/C?
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> > Behalf Of [EMAIL PROTECTED]
> > Sent: Friday, May 18, 2007 11:49 AM
> > To: ev@listproc.sjsu.edu
> > Subject: Re: Power Stering and A/C
> >
> > Wayne, at ev-blue.com has done this before...
> > He's got some really good pictures detailing how it might be done.
> > I wish I lived closer to his shop...
> > Anyway.
> >
> > Running accessories 'requires' an electric drive motor with
> > 2-half-shafts
> > (one to drive the trans, the other to drive accessories).
> >
> > http://www.ev-blue.com/photos.html
> >
> > This picture shows a 1-wire alternator for use for charging the 12-volt
> > battery, as well as an AC compressor.
> > http://www.ev-blue.com/98-S10/023.jpg
> >
> > There has been a variety of discussion regarding power steering...
> > When the drive-motor isn't turning, no power steering.
> > When it is, you're moving, after which the front wheels are easier to
> > turn
> > anyway.
> > (you do NOT want an unloaded series-electric motor turning, as it runs
> > the
> > risk of 'running away' and 'blowing up').
> >
> > Thus, you're probably looking at electric power steering, with some kind
> > of speed sensor to turn it on at low speeds (I have found its not really
> > needed above 15mph).
> >
> > My conversion isn't done, once its complete (and I've gotten it to
> > actually go down the road) I'll add other stuff, such as AC and whatnot.
> > The original vehicle (in my case) had 'manual' steering, so I'll
> > probably
> > stick with that.
> >
> >
> >
> >
> > "Guy Stockwell" <[EMAIL PROTECTED]>
> > Sent by: [EMAIL PROTECTED]
> > 05/18/2007 11:19
> > Please respond to
> > ev@listproc.sjsu.edu
> >
> >
> > To
> > <ev@listproc.sjsu.edu>
> > cc
> >
> > Subject
> > Power Stering and A/C
> >
> >
> >
> >
> >
> >
> > I'm new the the list and am ready to pull the trigger on a conversion,
> > but
> > was wondering if anyone has incorporated power steering and A/C as part
> > of
> > their conversion.
> >
> > Thanks in advance!
> >
> > Guy
> >
> >
>
>
--- End Message ---
--- Begin Message ---
Would a contactor controller be more efficient with a PM motor because you can
directly control motor voltage? Wouldn't a regular PWM controller do this
automatically?
TIA
From: Lee Hart <[EMAIL PROTECTED]>
<But you still have the usual PM motor tradeoffs. The PM motor is more
efficient at rated load (no field power losses). But at light load, it
is less efficient (because you still have full field strength, thus full
eddy and hysteresis magnetic losses). And at high peak loads, you risk
demagnetizing the magnets either from excessive current or excessive
temperature.>
____________________________________________________________________________________Be
a better Globetrotter. Get better travel answers from someone who knows.
Yahoo! Answers - Check it out.
http://answers.yahoo.com/dir/?link=list&sid=396545469
--- End Message ---
--- Begin Message ---
continues to flow as the field collapses. But is this voltage proportional
to the duty cycle and
actually higher than the battery pack voltage at some duty cycle less than
100% and RPM below base
speed? Is this how you can get regen at lower speeds?
You got it.
And if this is all true, then how can you control the voltage produced in
the off cycle? Do you
simply need to reduce the duty cycle or do you also need to adjust the field
current?
The battery itself controls the voltage produced. The output of a boost
converter is a current - it's up to the 'load' - in this case, the
battery - to control the voltage. You need to sense and control
the regen current - possibly using the same current sensing
arrangement as the motoring PWM side - one of those LEM hall effect
sensors is great for this sort of thing because you can put in in
the motor leg and sense both ways with one device. If you are really
ambitious, you can use the regen MOSFET as a synchronous rectifier
in addition to the motoring flyback diode - if you are using MOSFET's.
You should be able to gain a little bit of efficiency and quite a bit
less heat production...
A final question, should I be worried about generating too high a voltage
and protect the batteries and capicitors (omitted from the diagram) somehow
with like a high power zener (if there is such a thing)?
I will have 108V nominal battery pack. Is there such a thing as a 135V
or so Zener? How much power would it need to dissipate? Or, should I
try to simply keep the voltage down with the duty cycle?
The 'best' way to do this - at least that is how it is done with AC/BLDC
systems - is to have the brake pedal (or regen knob) control the current
setpoint with an additional input from the battery voltage. When
the battery voltage exceeds the regen voltage limit, the regen current
setpoint is reduced proportionally, over maybe a 3 or 5 volt region.
If the regen pot is arranged so the high voltage (maybe +5 volts) is
no regen, and if the pots are battery - referenced, then it should
be pretty easy - you need a zener diode and two resistors. When you hit
the regen pot, the signal drops to maybe 1 volt (lots of regen). When
the battery voltage hits 135 volts, it starts pulling the input
back up towards 5V, and you get no regen at 140 volts. You might want
to get a 100V zener and a handful of 3V and 15V zeners to 'trim' the
voltage you want. There are other ways but this one is easy to understand.
A few issues you would need to consider here are no so much from the
battery exceeding the desired voltage, but local high voltages
caused by inductance within the controller. Wiring is generally
inductive so when the regen FET turns off, the voltage across it
can be over double the actual battery voltage for just a few microseconds.
Unfortunately, these devices will not withstand overvoltages that
long so it'll blow up. If you are planning on designing one, make
sure you have access to a very high-speed 'scope so you can see
what's happening. You will need to be careful with switching speeds
and snubbing capacitors and snubbing networks so you don't blow
too much stuff up. By the way, from what I can tell, many of the
older Solectria MOSFET BLDC controllers have blown up - probably
due to these wiring inductance issues.
A dissipative regulator (big zener diode clamp) would be massively
expensive.
Railroad locomotives and industrial VFD's usually have big braking resistors
that are used for that purpose. You shouldn't need one in a car
because you have hydraulic brakes for when the batteries can't absorb any
more.
-Dale
--- End Message ---
--- Begin Message ---
Hey Bill
--- Bill Dennis <[EMAIL PROTECTED]> wrote:
> PlasmaBoy, Hi-TorqueBoy, or anyone else who knows:
Thats funny stuff, lol.
> Is general is there an RPM where 36V and 48V
> forklift motors are most
> efficient?
I've never tach'ed a motor in the lift so I really
have no idea where they run but would imagine their
somewhere around 3000 to 4000. I doubt there is an
all inclusive rule of thumb as they are all very
different really in the way they are wound. The best
general rule would be not to bog them down and keep
the RPM's up best you can. In general also most
forklift motors can be grouped into the same 6/7/8/9"
etc. sizes for your max RPM as the larger the comm the
lower the max RPM's
Hope this helps
Cya
Jim Husted
Hi-Torque Electric
____________________________________________________________________________________Need
a vacation? Get great deals
to amazing places on Yahoo! Travel.
http://travel.yahoo.com/
--- End Message ---
--- Begin Message ---
How about a contactor/rectactor type controller that used some form
of electronic switching, not PWM, but just an electronic on off switch?
I am not knowledgeable about solid state switches nor scrs, but is
there not a solid state version that would do this quietly?
Seems like most of the distress that people have with contactor
controllers is the noise. I, for one, like the lurch that you get on
that last hit into "high" voltage.
I have had great results using resistors for that slow speed running,
and think that a three level control would minimize the time that one
ran with a resistor
for those of you who don't need the heat! (Snowed in parts of Maine
last night!!!)
Hope to get more stuff on the Contactor Controller page this weekend.
Tom in Maine
--- End Message ---
--- Begin Message ---
The final plans are being put in place for the Power of DC race June
2-3.
Jim's building us a great motor to give away which will be cool.
On Saturday June 3, the Washington Chapter of the Sports Car Club of
America is setting up our AutoCross event and they are handling the
timing as well. That event starts at 10:30 am. From what I understand
the West Virginia University Electric Formula 1 racer will be racing
the AutoCross. That will be awesome to see.
We will have a big 70 Kw generator at the location and Tom Sigman, a
retiree from PEPCO, DCs local utility, will be on hand to set up the
generator and help with the charging.
The 8 mile Range Rally route has been planned out which will start
after lunch. A short section of this route will include Interstate 70
so your EVs should be highway capable.
And we've made plans for the ScooterCross. Kids under 16 are allowed
to race their electric scooters in the ScooterCross with their
parents permission. Bring your helmets. Knee pads and elbow pads are
also encouraged. The ScooterCross is an official event and we will
have trophies for the winners. We're going to wing it with the
electric go carts and E-bikes depending on how many show up. If only
one person brings an electric go cart we'll make sure they have an
opportunity to race it on the course.
And there is the Show-n-Shine after the cars arrive back from the
Range Rally.
The events on Saturday are Free, but we are accepting donations.
Lunch will be provided at the location for a reasonable price. Rest
room facilities are also going to be provided. Thanks to Mike Harvey
and Tracy for making all these arrangements for Saturday.
The NEDRA drag race at the Mason Dixon Dragway Sunday June 3 is set
up the same way as our previous other year's races. Gates open at
11:00 am and racing starts at noon. Shawn Lawless is bringing his
electric creations including AGNS which will be cool. Darrin is
bringing his updated 96 volt motorcycle and making a spider box.
If anyone has a particular 240 volt charging need please let Darrin
know so he can add that port to his box.
[EMAIL PROTECTED]
EVA/DC is bringing their Solar Racer, the Aztec, which competed last
year at the Power of DC.
I just reserved a room at the Super 8 Motel off Dual Highway Rt 40
which is a couple miles north of the Mason-Dixon Dragway (301)
739-5800. Rates there are $45.00 for doubles if you mention you are a
racer at the track. There are plenty of rooms available. The Super 8
is one of the track sponsors. Plenty of parking is available for
trailers there too.
Although I'm only about an hour from the track I thought it would be
better to get up there Friday night and stay through Sunday so I
don't have to keep going back and forth.
For maps, info on hotels and motels and other race info visit the
Welcome Page of the Power of DC site. http://www.powerofdc.com/
welcome.html
So everything is all set up for you guys and gals to join us so it
should be alot of fun.
And if anyone has any questions feel free to call me at 240-687-1678.
Chip Gribben
Power of DC
http://www.powerofdc.com
--- End Message ---
--- Begin Message ---
Jeff Major wrote:
> I agree with [John Wayland]. Even if there is a reducer
> between the motor and rear end. If it is a single fixed
> ratio drive, it is direct drive. If it is multiple ratio,
> it is a transmission. That has been the customary
> terminology for as long as I can remember.
Checking a few dictionaries, it is readily apparent that "transmission"
refers equally to single or multiple ratio gear boxes:
<http://dictionary.reference.com/browse/transmission>
<http://www.m-w.com/dictionary/transmission>
<http://dictionary.cambridge.org/define.asp?key=transmit*1+0&dict=A>
<http://www.askoxford.com/concise_oed/transmission?view=uk>
Any speed reducer between the motor ("engine") and axle is, by
definition, a transmission even though particular industries may favour
alternate terms ("reducer", etc.) for the device.
Indeed, the English term for transmisison, "gearbox", is perhaps the
most enlightening as it clearly describes any device ("box") containing
gears for the purpose of providing a change in speed.
Checking the dictionaries for their take on "direct drive" turns up one
hit:
<http://dictionary.reference.com/browse/direct%20drive>
This one suggests that it is the absence of a clutch mechanism between
the engine and prop (drive) shaft that qualifies a drive system as
"direct". However, the definiton of "direct" is "with nothing in
between", and since the motor ultimately drives the wheels, a "direct
drive" system must clearly be one with nothing in between the motor and
wheel; no clutch and no gear reduction.
John Wayland wrote:
> > Perhaps in a purely engineering environment where
> > everything is literal, but not in the normal
> > context of the automotive world (the world that
> > EVs are in) where direct drive 'means' that the
> > motor(s) 'directly drives' the rear end without
> > the aid of a multispeed transmission or the
> > inclusion of a clutch or torque converter.
So what then describes the drive configuration of a vehicle without a
rear end (or FWD differential), where motor(s) drive one or more wheels
through a fixed reduction? How about when one or more wheels are driven
directly by a motor(s) without and gear reduction?
I think Peter's point is that "direct drive" clearly must refer to the
most direct of drive configurations, which is where a motor directly
drives a wheel without any speed reduction between the motor and wheel.
Placing a speed reduction device (including a rear end/differential)
between the motor(s) and wheel(s) makes it a less direct drive
configuration, and precision in our terminology allows us to communicate
clearly which type of system we are discussing.
> > Example (1)
> >
> > When talking with the engineers from GM back in '96
> > about 'Sunnyside Up', the land speed Impact
> > (forerunner to the EV1), they too, referred
> > to the car as direct drive, since it had no
> > selectable gear ratios.
GM also inaccurately referred to the fixed-reduction transaxle as a
"transmission", so it hardly seems that their use of the term "direct
drive" should be taken as definitive... ;^>
It is also possible that the term "direct drive" was used by GM to refer
to the absence of a clutch or other means of disengaging the motor from
the wheels, and had nothing to do with the use of a single-speed
transaxle instead of a multi-speed unit.
> > Example (2)
> >
> > I work in the forklift industry, where nearly every
> > electric drive system is called 'direct drive'. The
> > 'drive unit' is never called a 'transmission', it's
> > always called the 'drive unit', and in pretty much
> > all the tech info they refer to the electric motor
> > as 'directly driving' the drive wheel(s) through a
> > gear reduction unit...they do not call it a
> > transmission...they do call it direct drive. In most
> > all the tech service manuals in the maintenance
> > sections, they warn about jacking up and securely
> > blocking the truck because of the 'direct drive' and
> > the ability of an electric motor to accidentally get
> > turned-on.
The last couple sentences here are the most telling: it is immediately
obvious that in this industry the term "direct drive" is used to refer
to the absence of a clutch or other means of disengaging the drive motor
from the wheels. This is the reason for the safety concern if the drive
wheels are not elevated during service/troubleshooting.
> > Example (3)
> >
> > Car and Driver wrote the story on my car...I had
> > nothing to do with it other than pushing to get
> > some of those who have helped with sponsorship
> > mentioned in the final copy. They are what most
> > everyone would call automotive experts. In the
> > article they call my car 'direct drive'...
> > "Maximum rpm is about 7000, which thanks to a 4:11
> > final drive, is just enough to get this direct-drive
> > car down the quarter-mile."
> >
> > If Car and Driver thinks a car without a
> > transmission and with an electric motor coupled
> > directly to the rear end is 'direct-drive',
> > that's good enough for me.
So, how many vehicles has C&D reviewed over the years that did not have
some form of transmission or transaxle? What makes them experts on
accurate terminology when referring to drive systems with which they
have little or no experience? ;^>
I expect that C&D referred to the vehicle using whatever terms it was
described to them in, and since you believe that "direct drive" is an
accurate description I'm sure it was mentioned at least in passing.
While I'm sure that many on the list would understand that someone using
the term "direct drive" is probably referring to eliminating the
transmission from their conversion, it would be clearer and less
ambiguous to state "directly driving the rear-end" to avoid possibility
of confusion with one of many other possible meanings (e.g. clutchless
conversions whether or not the ability to shift is retained, fixed
reduction vs multi-speed transmission, transmissionless conversions,
etc.).
If we ask non-EV'ers what a "direct drive" car is, how many have a clue,
and how many different interpretations do we get?
Cheers,
Roger.
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--- Begin Message ---
From: "Roger Stockton" <[EMAIL PROTECTED]>
Snipped Blah blah blah blah blah
Be it known to all on this list that when the term direct drive is invoked I
will consider it to mean a car without a mulitspeed transmission. I will
consider any form of single gear ratio drive whether it be driveline/rear
end, chain/sprocket, belt/pulley, or any other such contraption that can be
thought up a direct drive system.
You may if you wish refer to an electric motor as an engine and I will look
the other way, but do not refer to one of the above systems as having a
transmission unless you are prepared to pay the consequences.
Thank you for your time :-)
damon
_________________________________________________________________
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--- Begin Message ---
I've been working on my contactor controller, and have it setup so my
micro reads the throttle pot and turns on/off one of four contactors.
I've been testing it, and find the go-pedal control to be too "mushy".
I'm now changing it so there is a hand-selected speed switch input to
the micro, and the go pedal only turns on/off the selected speed.
If you are going to use silicon and deal with its heat and losses, you
might as well just PWM it.
Jack
Tom Gocze wrote:
How about a contactor/rectactor type controller that used some form of
electronic switching, not PWM, but just an electronic on off switch?
I am not knowledgeable about solid state switches nor scrs, but is
there not a solid state version that would do this quietly?
Seems like most of the distress that people have with contactor
controllers is the noise. I, for one, like the lurch that you get on
that last hit into "high" voltage.
I have had great results using resistors for that slow speed running,
and think that a three level control would minimize the time that one
ran with a resistor
for those of you who don't need the heat! (Snowed in parts of Maine
last night!!!)
Hope to get more stuff on the Contactor Controller page this weekend.
Tom in Maine
--- End Message ---
--- Begin Message ---
Hi Tom and All,
----- Original Message Follows -----
From: Tom Gocze <[EMAIL PROTECTED]>
To: Electric Vehicle Discussion List <ev@listproc.sjsu.edu>
Subject: Semi-electronic controllers?
Date: Fri, 18 May 2007 16:22:01 -0400
>How about a contactor/rectactor type controller that used
>some form of electronic switching, not PWM, but just an
>electronic on off switch?
>
>I am not knowledgeable about solid state switches nor scrs,
>but is there not a solid state version that would do this
>quietly?
I'd think you could hook up some Fet's in parallel
to do that but reg contactors are about the same or cheaper
and less complicated, less problems.
Noise, if it bothers people can be easily handled
by enclosing in a sound reduction box. Personally I like the
sound and moved mine so I could hear them better as they
were too quiet!!
I'm working on a cheap CC that should cost under
$20/2 200 amp cont contact set for parts with copper bars,
truck starter contactor disc or copper bar and maybe starter
contacts, some of which are silver or other contact
surfaces. I'll just use 1/16" silver sheet on the copper bar
instead of buying ready made contacts.
While drawing it, I noticed how easy it would be to
place a 6vdc battery in reverse voltage across the field to
give regen and maybe reverse.
Questions are how much voltage across the field
should I use?
Should it be variable?
Can I use the batt for reverse too?
Does the regular field wiring need to be removed by
contactors to work or could you just add the batt accross it
if enough voltage to overcome normal field voltage?
On other CC questions, can I S/P just the armatures
on 2 motor setups and leave the fields together for easier,
less contactors for reverse, maybe regen? I'm trying to
avoid 2 sets of reverse contactors.
Or just series/parallel the fields and reverse the
armatures instead?
Will an Altrax 7245 work without the field in
series?
>
>Seems like most of the distress that people have with
>contactor controllers is the noise. I, for one, like the
>lurch that you get on that last hit into "high" voltage.
If you set it up right you don't have a lurch. Using
Field weakening on the low voltage setting too you can get a
speed or 2 between high and low pack stages. Best way not to
have a lurch and better battery life, eff, is to let the
motor rpm run up to almost max in that speed before
switching to the next one.
On CC's, eff can go down if one shifts early too much
due to heavy current draws. Again by letting each speed wind
out solves this nicely along with a more smooth ride.
>I have had great results using resistors for that slow
>speed running, and think that a three level control would
>minimize the time that one ran with a resistor
>for those of you who don't need the heat!
If you do a lot of very slow speed driving, you
should consider a 12v or 12/24vdc stage/pack for starting,
parking lot, traffic jams instead of using resistors too
much, maybe even eliminate the resistors.
(Snowed in parts
>of Maine last night!!!)
Sweated at 90F with 90% humdity in Fla.
>
>Hope to get more stuff on the Contactor Controller page
>this weekend.
Thanks for doing that Tom. I have to get to a
faster connection to see all of it.
Thanks,
Jerry Dycus
>
>Tom in Maine
>
--- End Message ---
--- Begin Message ---
Hey Chip
--- Chip Gribben <[EMAIL PROTECTED]> wrote:
> The final plans are being put in place for the Power
> of DC race June
> 2-3.
>
> Jim's building us a great motor to give away which
> will be cool.
I was thinking that maybe you ought to give the motor
away to the slowest scootercross racer so that they
won't be slowest next year. I then thought that it
wouldn't help much to pay your bills though. I also
thought that it would probably make this years
scootercross the slowest in history LMAO 8^p
Anyway I hope EVeryone takes lots of pics for us west
enders so we get to partake in the EVent.
Sorry I was unable to get Lawless' Juiced up motor
finished in time to debut there (I know I suck) but I
will make sure you get the raffle motor there in time.
Again much love to Wayland who dumpster dove for this
core (man, I got to get a pic of his asscrack hanging
out on one of those dives 8^o) John has been a huge
help in my ability to do this kinda thing so I just
wanted to give some love back to the Princess for all
he does for the community.
I hope all have a great time who can attend, as for me
I'll have to settle for pics 8^( well that and
hopefully some fun stories 8^)
Cya
Jim Husted
Hi-Torque Electric
____________________________________________________________________________________Be
a better Heartthrob. Get better relationship answers from someone who knows.
Yahoo! Answers - Check it out.
http://answers.yahoo.com/dir/?link=list&sid=396545433
--- End Message ---
--- Begin Message ---
So with all that in mind here are two items that need clarification in my mind
for me to make a decision on who's side to be on:
1) What if a directly driven rear differential had a 1:1 ratio. Speed
reduction, No. Transmission by definition, No. Direct drive with no
decoupling mechanism, Yes?
2) What if you have a ring gear inside the rim of your vehicle and drive it
"directly" with a pinion from a motor driveshaft?
Speed reduction, Yes. Transmission by definition, Yes. Direct drive with no
decoupling mechanism, Yes?
And oh yeah one other:
3) If a 1:1 differential is still considered a transmission, even theough
there is no speed recduction, then what about the drive shaft itself? No speed
reduction, No decoupling mechanism, but still its is a transmission.
I think I'll still use the term "Directly driven rear-end" with a slang term of
"Direct Drive". The only other **more direct** form I can think of is a hub
motor with no reduction, and in that case I would say "hub motors".
MIke,
Anchorage, Ak.
----- Original Message -----
From: Roger Stockton <[EMAIL PROTECTED]>
Date: Friday, May 18, 2007 12:54 pm
Subject: RE: direct drive or transmission?
To: ev@listproc.sjsu.edu
> Jeff Major wrote:
>
> > I agree with [John Wayland]. Even if there is a reducer
> > between the motor and rear end. If it is a single fixed
> > ratio drive, it is direct drive. If it is multiple ratio,
> > it is a transmission. That has been the customary
> > terminology for as long as I can remember.
>
> Checking a few dictionaries, it is readily apparent that
> "transmission"refers equally to single or multiple ratio gear boxes:
>
> <http://dictionary.reference.com/browse/transmission>
>
> <http://www.m-w.com/dictionary/transmission>
>
> <http://dictionary.cambridge.org/define.asp?key=transmit*1+0&dict=A>
>
> <http://www.askoxford.com/concise_oed/transmission?view=uk>
>
> Any speed reducer between the motor ("engine") and axle is, by
> definition, a transmission even though particular industries may
> favouralternate terms ("reducer", etc.) for the device.
>
--- End Message ---
--- Begin Message ---
Hi Jack and All,
I put my resistor to go on each time the pedal
is pressed first before it going full power, a 2 speed
pedal, and switching other speeds by seperate switching,
preferably on a shift lever so it's somewhat like normal
gears. The resistor each time really helps keep from
breaking things if you start in top speed accidentally ;^D
A circuit like a relay on the motor leads so
you need to have a certain voltage on the motor before the
Field weakening or top speed comes on is a good mod as you
shouldn't use FW until at least 1/2 power or starting in top
speed.
----- Original Message Follows -----
From: Jack Murray <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Subject: Re: Semi-electronic controllers?
Date: Fri, 18 May 2007 14:15:28 -0700
>I've been working on my contactor controller, and have it
>setup so my micro reads the throttle pot and turns on/off
>one of four contactors. I've been testing it, and find the
>go-pedal control to be too "mushy". I'm now changing it so
>there is a hand-selected speed switch input to the micro,
>and the go pedal only turns on/off the selected speed.
>
>If you are going to use silicon and deal with its heat and
>losses, you might as well just PWM it.
I agree but that also applies to your micro. Diode
matrix, micro switches and relay's work well instead.
Jerry Dycus
>
>Jack
>
>Tom Gocze wrote:
>> How about a contactor/rectactor type controller that used
>> some form of electronic switching, not PWM, but just an
>> electronic on off switch?
>> I am not knowledgeable about solid state switches nor
>> scrs, but is there not a solid state version that would
>> do this quietly?
>> Seems like most of the distress that people have with
>> contactor controllers is the noise. I, for one, like
>> the lurch that you get on that last hit into "high"
>> voltage. I have had great results using resistors for
>> that slow speed running, and think that a three level
>> control would minimize the time that one ran with a
>> resistor for those of you who don't need the heat!
>> (Snowed in parts of Maine last night!!!)
>>
>> Hope to get more stuff on the Contactor Controller page
>> this weekend.
>> Tom in Maine
>>
>>
>
--- End Message ---
--- Begin Message ---
Has anyone thought to set up a google (or other) shared calender for
this list so all ev events worldwide can be more easily tracked?
With the volune of this list it is very hard to happen upon all the
right emails which announce events (many of which don't include location
such as the power dc one quoted below).
Also there should be an ev faq email that is resent once a week to the
list to give all the basic refrains and tech notes that are continually
rediscussed. It would be really helpful to avoid long trains of
discussion that are repeated and should be long and fully enclusive
since it will only go out once a week.
On Fri, 18 May 2007 2:37 pm, Jim Husted wrote:
Hey Chip
--- Chip Gribben <[EMAIL PROTECTED]> wrote:
The final plans are being put in place for the Power
of DC race June
2-3.
Jim's building us a great motor to give away which
will be cool.
I was thinking that maybe you ought to give the motor
away to the slowest scootercross racer so that they
won't be slowest next year. I then thought that it
wouldn't help much to pay your bills though. I also
thought that it would probably make this years
scootercross the slowest in history LMAO 8^p
Anyway I hope EVeryone takes lots of pics for us west
enders so we get to partake in the EVent.
Sorry I was unable to get Lawless' Juiced up motor
finished in time to debut there (I know I suck) but I
will make sure you get the raffle motor there in time.
Again much love to Wayland who dumpster dove for this
core (man, I got to get a pic of his asscrack hanging
out on one of those dives 8^o) John has been a huge
help in my ability to do this kinda thing so I just
wanted to give some love back to the Princess for all
he does for the community.
I hope all have a great time who can attend, as for me
I'll have to settle for pics 8^( well that and
hopefully some fun stories 8^)
Cya
Jim Husted
Hi-Torque Electric
____________________________________________________________________________________Be
a better Heartthrob. Get better relationship answers from someone who
knows. Yahoo! Answers - Check it out.
http://answers.yahoo.com/dir/?link=list&sid=396545433
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
--- End Message ---
--- Begin Message ---
MIKE WILLMON wrote:
> So with all that in mind here are two items that need
> clarification in my mind for me to make a decision on who's
> side to be on:
Please let's not make it a question of "sides"; it already looks as if
Damon has taken offense to my choosing to challenge John Wayland's
interpretation. ;^>
I think the one common thread to the sprint car, material handling, EV1,
White Zombie, etc. examples is that all of these systems lack a clutch
or other means of decoupling the prime mover from the load.
The White Zombie and sprint car both have no reduction between the motor
and wheels other than that in the rear-end. The material handling (lift
truck) and EV1 cases both have additional reduction between the motor
and final drive.
It seems fairly clear then that prior convention has been to use the
term direct drive to refer to drive systems lacking a clutch mechanism,
not to the presence or absence of single or multiple reduction ratios
between the motor and wheels. In the EV world, however, we refer to
these systems simply as "clutchless".
EVs open up the possibility of having a wheel mounted directly (or
indirectly via an axle shaft) to the motor shaft, which is the ultimate
direct drive system. When the motor is located within the wheel, we
refer to these as "hub motors", which are understood to be direct drive
even though many hub motors actually include a speed reduction between
the shaft and wheel.
You list some interesting special cases. Here are a few others:
- a vehicle with a multi-speed transmission that is locked in a single
gear: direct or not?
- a vehicle with a single fixed reduction between the motor and wheel,
but with a clutch mechanism allowing the motor to be decoupled from the
wheel: direct or not?
I don't know that it is important to try to sort which of these
possibilities could be lumped into the "direct drive" universe or not.
I think the important thing is to recognise that there are a whole bunch
of quite different drivetrain configurations possible in between the
extremes of one with a clutch and multi-speed transmission (unarguably
not direct drive) and one with the motor directly coupled to the wheel
(unarguably direct drive). If we are to have meaningful discussions we
might want to be more selective (precise) in our use of the term "direct
drive" as there can be important differences and considerations between
the various systems.
Perhaps the compromise middle ground is to use direct drive to refer to
all drive configurations with a fixed reduction ratio between the
motor(s) and wheel(s), and no means of decoupling the motor from the
wheel rather than the strictest definition of only such systems with a
1:1 ratio between the motor and wheel?
Cheers,
Roger.
(PS: with respect to your special cases, the definitions of
"transmission" do not require that the gears have to provide a speed
change (ratio other than 1:1), so strictly speaking it could be that
even a gearset providing a 1:1 ratio could be considered a transmission.
Even with a 1:1 ratio, a diff will introduce a change in speed/torque
between its input and output(s) as the vehicle turns or as one wheel
loses traction, so I think it would technically always constitute a
"transmission" type device, albeit a very specialised one. Otherwise we
get into situations such as me stating that my transmission is not a
transmission when in 4th, since 4th gives a 1:1 ratio... ;^)
--- End Message ---
