EV Digest 5393
Topics covered in this issue include:
1) Low rider floodie quest
by "Mike Phillips" <[EMAIL PROTECTED]>
2) Re: Round Trip Range on 48 volts
by "jmygann" <[EMAIL PROTECTED]>
3) RE: Arctic Leash
by "Roger Stockton" <[EMAIL PROTECTED]>
4) Re: Neon (Lamp, not John) Questions
by Lee Hart <[EMAIL PROTECTED]>
5) Re: Switched Capacitor Equalization of Long Strings WAS: Some
problemstosolve
by Lee Hart <[EMAIL PROTECTED]>
6) Re: Honda 600 (in Texas?)
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
7) RE: Switched Capacitor Equalization of Long Strings WAS: Some
problemstosolve
by "Roger Stockton" <[EMAIL PROTECTED]>
8) RE: Metro Brake Cylinder (Was: Angle Iron to Chassis)
by "Roger Stockton" <[EMAIL PROTECTED]>
9) RE: Knee Point - Does anyone understand this?
by "Roger Stockton" <[EMAIL PROTECTED]>
10) Logos (was RE: sheilding for zilla wiring)
by "Roger Stockton" <[EMAIL PROTECTED]>
11) Re: longest range?
by "Charles Whalen" <[EMAIL PROTECTED]>
12) Re: Honda 600 (in Texas?)
by Mark Hastings <[EMAIL PROTECTED]>
13) Re: Arctic Leash
by Nick Austin <[EMAIL PROTECTED]>
14) RE: Albright Contactor rework
by Cor van de Water <[EMAIL PROTECTED]>
15) Re: Otmar's motor speed sensor - Kostov's
by "Rich Rudman" <[EMAIL PROTECTED]>
16) Re: Albright Contactor rework
by Neon John <[EMAIL PROTECTED]>
17) RE: Albright Contactor rework
by "Bill Dennis" <[EMAIL PROTECTED]>
18) Re: Honda 600 (in Texas?)
by Neon John <[EMAIL PROTECTED]>
19) Re: Neon (Lamp, not John) Questions
by Neon John <[EMAIL PROTECTED]>
--- Begin Message ---
Is there a floodie available that someone has tried that is not over
7" tall? My truck can only support 7" and shorter.
Mike
--- End Message ---
--- Begin Message ---
Thanks
Charged pack and after a couple of hours sitting the pack measured
53.7 Volts , so I hope I did not hurt anything ....
--- In [EMAIL PROTECTED], "Death to All Spammers"
<[EMAIL PROTECTED]> wrote:
>
> > Thanks,
> > I measured right after I stopped ... guess I should have waited a
> > bit.
> > If it was 50% what would be the reading ?? 80% ??
> >
>
> For 12V floodies, full charge is around 12.6V, 50% at 12.2V and fully
> discharged at 11.8V - these are all measured at rest, and can vary
> with temperature.
>
--- End Message ---
--- Begin Message ---
Patrick Clarke [mailto:[EMAIL PROTECTED] wrote:
> Also FWIW, while I don't remember the gauge of the current charging
> cable (with an inline timer), I don't remember it ever
> growing warm. Of course, I've never used it rolled up.. ;-)
If you are going to have a problem, it will be with the cord rolled up.
I don't know what charger they used, but as I recall the NEVCO Gizmo
people also thought the retractable cord was a neat idea until they
started melting cords.
> I like this idea! What would be an "appropriate" extension
> cord? We can normally park within ten feet of our household
> outlet, so it needn't be that long (although it might be nice
> to have a longer one for emergencies or the unexpected).
By appropriate, I was just meaning one with an appropriate connector on
one end to connect to the wall outlet and a connector on the other end
to connect to the EV's inlet.
I think the easiest in this case is to make a short adapter with an
L14-30 female on the EV end and a standard 120V 15A male plug on the
other. This adapter need only be 1 foot long. Then, you can plug the
EV in using any off-the-shelf 120VAC extension cord of the desired
length (and still be able to use the extension cord for other duties
if/when required).
I use an L14-30 connector at the EV, so I have two different extension
cord needs: one to allow me to plug into a 120V outlet and another to
allow plugging into 240VAC, so I have two such adapters.
> Do
> they make extension cords with two male ends or will I have
> to fabricate one?
You don't want an extension cord with two male ends!
If you are connecting AC to an onboard charger (or other appliances,
such as your ceramic heater), then you want a male connector on the EV.
The cord between the EV and wall outlet will have a male connector on
the wall end and a female connector on the EV end. This way there are
no exposed contacts with live AC on them when the cord is plugged into
the wall, just like normal extension cords.
> One other factor that may or may not come into play is a need for an
> auxiliary heater
> The low-tech/cheap solution was to purchase a ceramic space
> heater that lives in the back hatch area, operable by a timer.
> It would turn on 15 minutes before we'd leave in the morning to
> take the chill off the car.
Presumably by the time the heater timer kicks it in, the charger should
either have completed, or at least be operating at low power in the
final charging stages, so operating both from the same cord may not be
an issue.
If you wanted to be sure, you could use a relay on the output of the
timer to switch power between the charger and heater so that only one is
ever on at a time. Basically have the normally closed contacts of the
relay supply power to the charger; when the timer decides it is time to
power up the heater, it powers the relay coil and the contacts transfer
so that AC is now connected to the heater instead of the charger.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Bill Dennis wrote:
> How do the voltage ratings on neon lamps work?
A standard neon indicator lamp turns on at about 60-70 volts, and once
on, will have about 55-60 volts across it. There is always a series
resistor to drop the rest of the applied voltage.
> If a lamps says that its voltage rating is 120V, does this mean that
> it won't turn on until 120V, or that it should never be connected to
> more than 120V?
The "120vac" line voltage is actually going from 0v to +170v, to 0v, to
-170v, and back to 0v sixty times per second. The neon lamp looks like
an open circuit until the instantaneous voltage hits that 60-70v. Then
the neon gas ionizes, it lights up, and draws current. The voltage
across the lamp drops to 55-60v. The difference between this and the AC
line voltage appears across the series resistor. The current (which
controls the brightness) is limited by the series resistor; without that
resistor, the lamp would try to draw a huge current and would be
immediately destroyed.
When the AC line voltage passes its peak and falls back below 55-60v,
the neon lamp "switches off" and becomes an open circuit again. This
whole cycle repeats in the negative half cycle.
The series resistor is what determines the "rated" voltage for a neon
indicator. A "120v" indicator has a 22k-100k resistor. A "240v" has a
47k-220k resistor. You can change the resistor or add another one in
series for any voltage you like. just be sure the resistor has a high
enough voltage and power rating.
> (with a 120V pack, will the lamp be okay at a fully-charged 160V)?
A 120vac neon lamp and resistor will be fine at 160vdc. The current (and
brightness) will be a little higher, but that won't shorten its life
enough to matter (from maybe 25,000 hours to 15,000 hours :-)
--
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 ---
Mike Phillips wrote:
> I see that the systems in other battery chemistry's look like they
> are using voltage as well for soc measurements. The IC's I see for
> most chemistry's are all voltage based. So is it that much more
> expensive/complex to make something that counts ah's on each battery?
Personally, I think they measure voltage because it is cheap and easy.
To measure actual state of charge, you'd need to watch current in/out of
the battery and accumulate amphours; or measure voltage and current and
infer state of charge from them by some empirical equation.
--
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 ---
It only takes 90 amps to fry an ETEK. Watch out. LR.......
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: "Lawrence Rhodes" <[EMAIL PROTECTED]>
Sent: Friday, April 21, 2006 9:57 AM
Subject: Re: Honda 600 (in Texas?)
Maybe, but just for around town you shouldn't be near the "330A for 1
minute"
peak rating.
That might work. It'd be very limited. Good chance you would fry the
motor. LR....
----- Original Message -----
From: "Death to All Spammers" <[EMAIL PROTECTED]>
To: "Neon John" <ev@listproc.sjsu.edu>
Sent: Thursday, April 20, 2006 10:55 PM
Subject: Re: Honda 600 (in Texas?)
>> >This microcar might make be a good basis for an EV (for someone
> else, that is):
>> >
>>
>>http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4631382724
>> >
>>
>> Nah. at least not if you want any batteries on board :-)
>>
>>
>
> Just thought maybe 4 Optimas, 4QD-48-300 controller and an Etek
> connected directly to a donor transaxle (a Fiat, maybe?) for short
> errands, then spring for lithium in the future to try for longer range.
>
>
>
--- End Message ---
--- Begin Message ---
Mike Phillips [mailto:[EMAIL PROTECTED] wrote:
> The IC's I see for most
> chemistry's are all voltage based. So is it that much more
> expensive/complex to make something that counts ah's on each battery?
Sure, it is more expensive since have to monitor current as well and may
only have needed to monitor voltage otherwise. It may be a case of the
80/20 rule; just using voltage may give much of the benefit for only
part of the cost of the full solution.
However, some ICs *do* monitor both, for instance TI/Benchmarq's
bq20z80.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Bill Dennis [mailto:[EMAIL PROTECTED] wrote:
> There were three steps involved.
Thanks; this sounds about as close to a direct bolt-in as one could hope
for!
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Dale Curren [mailto:[EMAIL PROTECTED] wrote:
> I thought the fields were weakened (less current) as the
> motor rpms increased.
Correct, but since armature current *decreases* as motor RPM increases
(due to the increasing back-EMF), the result is that field current
decreases as motor current decreases. Turning this statement around
reveals that field current *increases* as armature current *increases*.
> Is the previous sentence correct? Doesn't the field current decrease?
Not as I've described it. Bear in mind that unless you provide the
controller with a speed sensor input (and many manufacturers don't want
to spend the money on an extra sensor if they can avoid it), it doesn't
know how fast the motor is spinning and so cannot, strictly speaking,
weaken the field as RPM increases. What it can see is motor voltage and
current, so field strength is typically varied as a function of the
armature current.
Since armature current is proportional to torque, when the controller
sees high armature current it "knows" you want high torque from the
motor, and so it makes sense to increase the field strength (increase
field current) to generate more torque. This is exactly the same
characteristic as a series motor. When armature current is low, the
assumption is that motor speed is high such that you simply can't force
more current into the motor, so reducing the field strength makes sense.
> >Eventually the field current reaches some maximum level, and remains
> >at that level no matter how much higher the armature current climbs.
>
> Doesn't the field current reach a lowered (rather than maximum) level?
You are still envisioning the field current behaviour vs motor speed.
Yes, as motor speed increases, the field current will drop to some
minimum value.
I was describing the behaviour of field current vs armature current.
For a given voltage, the armature current will also drop with speed
which results in the relationship you have in mind. However the
controller is typically varying field current only as a function of
armature current (it often doesn't know the motor speed), so the
relationship is drawn with armature current increasing along the
horizontal axis and the field current increasing along the vertical
axis. In this picture, the field current starts off at some minmum
value (no matter how low the armature current, the field will not be
allowed to drop lower than this), as aramture current increases, so does
the field current. Eventually, the field current reaches some maximum
value and will not be allowed to climb any higher no matter how much
higher the armature current climbs.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Ryan Stotts [mailto:[EMAIL PROTECTED] wrote:
> Here's some from Optima:
>
> http://www.optimabatteries.com/publish/optima/americas0/en/con
> fig/news/logos.html
Thanks! Kind of small, but it may still be better than scanning one of
my Optima stickers.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Steve,
On the 29 I'm be long distance racing my work truck 40 golf cart batteries
, for 3 hours and will be shooting for 135+ miles ( to beat that Rave EV )
I guess you don't have to worry too much about that. The longest I've ever
done is 132 miles. At 135+ miles, you'll definitely beat me, especially at
45-50 mph (with my "barn-door" aero kicking in and penalizing a big
efficiency/range hit above 40 mph). :-( My overall range seems to be down
a bit in the last month or two; not sure why, I think we've just gotten a
little lazy in our diving habits, crushing the egg under the pedal and all
that.
Hhhhmmmm, didn't realize you'd done better than 120, 130 even. Seems like
the deck -- (or more specifically, your big double-layer bed, above and
below) -- is stacked against me ... with a hell of a lot of lead! Maybe you
should rename it "White Beastie"! :-)
With all you got goin' on to prepare for next weekend, I guess we won't see
you at Deerfield tomorrow. In addition to EVs, this year's main theme is
going to be solar power. Hope I can get away from our Florida EAA exhibit
for a while to explore all the PV stuff as I've been working on my PV plans
for a long time now and want to complete the second half of the
"EV + PV = Independence" equation. Design engineering the mounts for
hurricane-force wind loads is the big challenge; going all the way down to
24" spacing (every single truss) on the standoffs looks like it will do the
trick but makes the installation very expensive. (But of course a Cat 5,
150mph, will take the roof off the house anyway, so yeah, those PVs might
remain attached on their mounts to the roof, but the roof itself will be
over in my neighbor's yard. Not much good they'll do me over there. Maybe
he can use them to fire up his electric grill.) :-) Now if I could only
get a roofer ... Called around to every roofer in this area, all have an
18-month waiting list to do new roofs or any roofing work whatsoever ... the
result of 2 years worth of devastating hurricanes. That's the big
bottleneck at this point. But that's getting OT.
Looking forward to next weekend's electric mini Le Mans (1/8 scale);
soliciting tips from some of the experienced RAV drivers. Looks like I'm
the underdog. Well, I guess I'm just trying to downplay expectations here
so I don't look so bad if/when I get my ass kicked next weekend. :-)
Charles
----- Original Message -----
From: "steve clunn" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Friday, April 21, 2006 9:44 AM
Subject: Re: longest range?
I was on the tv news the other day , they started off with a shot of me
smoking the tires for a good 80 feet , reporter " not your dad's electric
car...." . I'm on my second set of tires , got some big 265 15's and it
still spins them like I'm on ice ( in 4th gear ) . I'm very happy with the
net gain 11motor, the spec sheet says 2times the torque for the same
amp/volts as a 9 , ( 1/2 rpm of course ) so going right to the rear end
looks very do able , .
Vs
On the 29 I'm be long distance racing my work truck 40 golf cart batteries
, for 3 hours and will be shooting for 135 +miles ( to beat that Rave EV )
, after the rally , I'll be driving the same truck to ev car show in Miami
over 100 miles south , with a stop in between for charging , rest. then
back home Sunday night . I could be putting 400 ev miles on it that
weekend .
Steve Clunn
one Ev is good but 2 is Better ( I liked the ev better cartoon )
----- Original Message -----
From: "Ryan Bohm" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, April 20, 2006 11:00 PM
Subject: Re: longest range?
Steve,
but the drag racing seems to be getting the most attention right now
:-) .
Steve Clunn
Haha - and you're quite the contributor :) I've seen your video laying
rubber in your truck, LOL.
-Ryan
--
- EV Source <http://www.evsource.com> -
Selling names like Zilla, PFC Chargers, and WarP Motors
E-mail: mailto:[EMAIL PROTECTED]
Toll-free: 1-877-215-6781
--- End Message ---
--- Begin Message ---
90 amps? I regularly push 100 - 110 amps at ~42 volts through mine for 5-10
minutes or more without any ill effects. Or at least not any ill effects that I
have noticed. Most of the time I run it between 70-90 for about half an hour
without a rest.
Lawrence Rhodes <[EMAIL PROTECTED]> wrote: It only takes 90 amps to fry an
ETEK. Watch out. LR.......
----- Original Message -----
From:
To: "Lawrence Rhodes"
Sent: Friday, April 21, 2006 9:57 AM
Subject: Re: Honda 600 (in Texas?)
> Maybe, but just for around town you shouldn't be near the "330A for 1
> minute"
> peak rating.
>
>> That might work. It'd be very limited. Good chance you would fry the
>> motor. LR....
>> ----- Original Message -----
>> From: "Death to All Spammers"
>> To: "Neon John"
>> Sent: Thursday, April 20, 2006 10:55 PM
>> Subject: Re: Honda 600 (in Texas?)
>>
>>
>> >> >This microcar might make be a good basis for an EV (for someone
>> > else, that is):
>> >> >
>> >>
>> >>http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4631382724
>> >> >
>> >>
>> >> Nah. at least not if you want any batteries on board :-)
>> >>
>> >>
>> >
>> > Just thought maybe 4 Optimas, 4QD-48-300 controller and an Etek
>> > connected directly to a donor transaxle (a Fiat, maybe?) for short
>> > errands, then spring for lithium in the future to try for longer range.
>> >
>> >
>> >
>>
>>
--- End Message ---
--- Begin Message ---
On Fri, Apr 21, 2006 at 09:55:27AM -0700, Patrick Clarke wrote:
> Do they make extension cords with two
> male ends or will I have to fabricate one?
Public service announcement:
Never make an extension cord with two male ends!
If you plug one male end into the outlet, then you have live conductors
sitting on the other side ready to shock you!
Make a male inlet, and connect the female end of an extension cord into that.
Thanks!
--- End Message ---
--- Begin Message ---
Bill,
I wound many coils by hand, there is no 'facilities' to
change the voltage on a coil - if you have a small drill,
file or grinder to take care of the stakes and a set of
screws to put back in their place, then all the rest you
need is the thicker wire for rewinding and patience.
To make the existing contactor work at 48V you may need
to modify the spring to allow it to close faster.
Success,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Bill Dennis
Sent: Friday, April 21, 2006 7:10 AM
To: ev@listproc.sjsu.edu
Subject: RE: Albright Contactor rework
Dang, I've got two of these wired into my EV already, wired with 48V. I
don't have the facilities or expertise to rewind them, either. I wonder if
I should add a circuit to my KSI so that it won't all the contactors to
close until after the controller is precharged.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Neon John
Sent: Thursday, April 20, 2006 10:46 PM
To: ev@listproc.sjsu.edu
Subject: Albright Contactor rework
Y'all may remember the group purchase on the Albright SW200A-678
contactors with the 56 volt coils that was organized last year. I
bought 8 (and sure wish I'd bought more :-)
I finally got time today to take the solenoid apart and compute the
new winding for 12 volt nominal service. Following is an excerpt from
my shop log book detailing the work.
Before I did anything, I tested the contactor as-found. I was not
impressed. With almost 53 volts (48volt pack on trickle) on the coil,
the armature just sorta sidled into place. Not the snap that we
expect of a high current contactor. I tested a couple more just to
make sure I didn't get a fluke. I didn't. I could just imagine these
contacts gliding listlessly closed into non-pre-charged controller
capacitors. The fireball should be entertaining, at least.
This was an unsatisfactory condition so after poking around with a
dynamometer (in this context, a spring-scale-like device for measuring
force) to see just what kind of starting force was generated by the
solenoid, I decided to design for 4X the starting force. That meant
about 4X the ampere-turns as the original coil.
The frame of the solenoid is staked together during manufacture.
Disassembly required I grind off the stakes and carefully lever the
frame apart. Once the frame was apart, the blue outer plastic sleeve
came off easily after I unsoldered the wires (photos on my web site
later) to expose the windings. Fortunately these were random-wound
bobbins without any potting compound. What follows is from my log
book.
John
-----------------------
04/20/06
Stock coil ------------------------------
At 51.4 volts, 225ma flows, computing to 228 ohms
Ohmmeter measures 207 ohms cold. Two different meters agree. Probably
the difference between cold and hot ohms.
With 52 volts on the solenoid, the core temperature (looking down the
solenoid bore with an IR pyrometer) rose to 157 Deg. and stabilized.
The outer plastic temperature was 129 deg.
Modified Coil - 12 volt nom service ------
At Jerry's (electric motor) shop.
Unwound the spool on Jerry's winding machine and measured the wire
gauge more precisely after burning off the insulation. 5008 turns of
#29 wire.
Computed 1200 turns of #21 wire for 12 volts.
On the bench with 13.87 volts on the coil, the initial current was
2.153 amps. The temperature started rising rapidly. After an hour in
free air the outside temperature was 207 degrees and stable and the
current had dropped to 1.966 amps. (Ain't Boltzmann grand?) That
works out to a hot resistance of 13.87/1.966 = 7.055 ohms.
(This is Class H wire so the temperature isn't anything to get excited
about. The plastic bobbin is the limiting factor. It feels like some
sort of cheap filled polyethylene or maybe nylon.)
This is a bit hot, though it would work in the EV because that much
voltage will not be available at the coil terminals. I'm going to
shoot for 1.0 amps holding at 12 volts for the first try. That
indicates 12 ohms. A peak/hold driver consisting of a 4.7 ohm
resistor shunted by a 50k uf cap should do the job, giving a time
constant of 0.24 seconds. The 4.7 ohm resistor will need to be 5
watts at least. A 10 volt cap would work, though I'm going to use a
16 volt or greater for safety margin.
If less than 1 amp can hold the solenoid in then I'm going to try 0.75
amps and then 0.5 amp, trying for the least holding current that will
hold the solenoid in even over rough terrain. For 0.75 amps at 12.0
volts, I'll need 16 ohms total. With 7 ohms in the coil, 16-7= 9 ohms
series resistor, shunted by a 30kuf cap for about the same time
constant.
This time constant should give enough of a current pulse to hammer the
contactor closed, yet let the contactor cycle in less than half a
second if necessary. I'll probably use a standard 8 ohm sand resistor
from Rat Shack and let the light gauge hookup wiring supply the other
ohm.
The spool is too full for the blue cover to fit back on so I wrapped
the coil with Scotch 88 after dribbling some thin epoxy into the
turns. The spool is of too cheap a grade of plastic to dip and bake.
For the next coil I'll use 22ga wire which will be less filling and
will allow the blue spool cover to go back on.
---- NOTE -----
These calculations are for ordinary enameled coil winding wire and NOT
Inverter-Grade wire. IG wire has a heavier insulation so the fill
factor is larger and fewer turns will fit.
To do:
* wind another coil with 22 ga wire.
* fit an LVDT to the armature and scope the contact motion.
* Test at 0.5 and 0.75 amps holding current.
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
--- Begin Message ---
Hey Jim..
One I have a burnt 8 incher comm. We shorted a pair of segments when testing
the old DCP Raptor 1200s. It's in pretty good condition. I need to get it
your way since it's gathering dust up here.
Roger, Neon..other Kosty helpers..
What I was envisioning is somthing that bolts onto the Fan end shaft so I
just install the sensor housing that Otmar sells. Since I have one...
The problem is I AM KEEPING THE DARN FAN.!!!!! I need all the cooling I can
get... and I know when and how it works. Hot days means I run in 1st up
against the Rev limiter... The vacume cleaner sounds tells me I am sucking
LOTS of air.. I don't have to be trained to not Lug my motors. ...I just
need the darn tach to work so I don't screw up. Yes Rod I remember....a
certain 9 incher.. Oh By the way it's still in my shop, waiting for pickup.
The thing is the nut holds the fan on, and there is no center bore or 1/4-20
threaded hole...like the AvDCs have. So.. without inventing the wheel again,
I was hoping somebody had Canned solution.
Toothed wheels don't cut it on the HB2 input, The old DCP opto sensor..Kinda
worked, But the T-ReX always had issues withit. I cut a slot in the screen
and painted white stripes and the rest black. The sensor worked but the tach
circuit in the T-rex did not.
So.. got 8 incher armature.. need something to bolt onto the fan end of a
Kosty to mount the magnet wheel onto.
Rich Rudman
Madman...with a spring cold..darn it!!
----- Original Message -----
From: "Jim Husted" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, April 19, 2006 5:09 PM
Subject: Re: Otmar's motor speed sensor - Kostov's
>
> Hey Rich, all
>
> FT just dropped off a couple of 9" Kostov's last week and I went and
looked at them before I re-read your dealing with an 11", but if this has a
fan shroud like the 9" then it'd be easy to install a standard sensor.
You'd need to drill and tap the hole in the shaft and then machine the
shroud hole. The shroud is to thin to drill and tap so I'd either rivit the
sensor on or braze some nuts or backing plate to the shroud. For the cherry
on the top you'd need to do up a small shaft exstension to stick out the
shroud.
>
> If you're to busy (after playing "Battery Mom" on MG, LMAO) then shuttle
it down and I'll set it up (I need more motors from you or I'll never save
up for a PFC-20, lmao!!) If nothing else maybe I could machine up the
extension or what ever you're needing.
>
> Being that I just got my eyes on a Kostov I noticed that the field coils
are perfect with all damage on the comm and brushes. Whimpy comm bars are
the blame, and in fact have almost no meat at all to them, so watch the comm
(I know I'm telling you 8^ P ). While carrying the Kostov housing over to
my bench I "accidentally tripped" and the housing slipped right over Marko's
ADC8 armature, LMAO!!! I was amazed at how well it fit in there although
the arm laminations are a bit longer than the stock arm. So EVer since FT
left last week I've been pondering an ADC/Kostov mutant. Just need to get a
burnt ADC8 arm to work with 8^ ) With the bigger brushes, better comm, and
courser windings I'm betting that sucker would scoot something along quite
quick 8^ )
> Anyways hadn't posted in a bit and thought I'd throw into the mix.
> Cya
> Jim Husted
> Hi-Torque Electric
>
>
> ---------------------------------
> Yahoo! Messenger with Voice. PC-to-Phone calls for ridiculously low rates.
>
--- End Message ---
--- Begin Message ---
On Fri, 21 Apr 2006 08:09:53 -0600, "Bill Dennis" <[EMAIL PROTECTED]>
wrote:
>Dang, I've got two of these wired into my EV already, wired with 48V. I
>don't have the facilities or expertise to rewind them, either. I wonder if
>I should add a circuit to my KSI so that it won't all the contactors to
>close until after the controller is precharged.
All you need is a drill motor, a vice to clamp it in and some
all-thread. The winding machine makes it easier but I've wound many a
coil at my bench with nothing more than that. I'm going to put some
photos on my website this weekend.
About the KSI, I don't know. I'd certainly want to have someone close
the contactors while I watched them. It may not be a problem, I just
don't like to see high current contacts operate that slowly.
I'm going to actually measure the motion on one because I have the
stuff to do it but you can get a good idea of the closing speed if you
have an o-scope and a current shunt. As the armature in the relay
moves, it generates counter-emf and varies the reluctance of the
magnetic circuit. Both oppose the build up of current. If you scope
the current going to the coil, you'll see it start to build in the
standard LR time-constant but as the armature starts moving, the
current either levels off or actually decreases, depending on the
design. When the armature slams home, the current continues to rise
at the LR time constant. The actuation interval is quite obvious once
you see the waveform.
Interesting story about this phenomena in the nuclear plant. This
current waveform is fairly well known among those dealing with
electromagnetics but not generally known in the EE world. Inside the
containment of Sequoyah NP are a couple of huge solenoid-operated
valves. For a variety of reasons, mainly having to do with the
extremely harsh environment (potentially 50 psi of steam, maybe 4-500
deg F and potentially high radiation), instead of motor-operated
valves, this application used huge solenoids. Several inches in
diameter and over a foot long, operated on 250VDC.
These valves were critical to the reactor's safety so there were two
in series (hydraulically, not electrically.) The actual operation had
to be verified periodically which involved either entering the
containment and exposing workers to radiation or attaching an LVDT or
similar transducer to the valve stem. The LVDT wasn't reliable and
man-REMs are to be avoided whenever possible.
We were noodling this over in the office one day. I'd just designed
and had the shop build a hydraulic pulse generator. This thing would
generate a 2200 psi square wave with a rise time of under 10ms. It
used a special dual-coil solenoid valve that would open in about 1ms.
One coil got a capacitor discharge into it to kick the plunger and the
other coil was the holding coil. The coils were operating at the edge
of the envelopes and I'd been measuring the speed using this current
technique.
Suddenly an idea dawned. I could verify those solenoid valves'
operation without doing anything inside the containment. We grabbed a
tech and hauled down to the instrument room, put a shunt in line,
scoped it and had the control room operator cycle the valve a few
times (during startup testing so the plant wasn't hot.) Viola!! The
prettiest motion waveform one could ask for.
Of course, in an NP, you don't just DO things, you have to kill a few
trees first. Westinghouse and TVA Engineering Design had to get
involved, do a bunch of analyses and a lot of testing - waveform vs
actual motion and all that. But in the end, my procedure was adopted
and AFIK is still in use. Those valves can be tested from the comfort
of the air conditioned Aux Inst room.
John
>Y'all may remember the group purchase on the Albright SW200A-678
>contactors with the 56 volt coils that was organized last year. I
>bought 8 (and sure wish I'd bought more :-)
>
>I finally got time today to take the solenoid apart and compute the
>new winding for 12 volt nominal service. Following is an excerpt from
>my shop log book detailing the work.
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
--- Begin Message ---
Thanks, Cor. By "facilities" I referring to the electric motor ship with
the unwinding equipment that Neon mentioned.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Cor van de Water
Sent: Friday, April 21, 2006 2:04 PM
To: ev@listproc.sjsu.edu
Subject: RE: Albright Contactor rework
Bill,
I wound many coils by hand, there is no 'facilities' to
change the voltage on a coil - if you have a small drill,
file or grinder to take care of the stakes and a set of
screws to put back in their place, then all the rest you
need is the thicker wire for rewinding and patience.
To make the existing contactor work at 48V you may need
to modify the spring to allow it to close faster.
Success,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Bill Dennis
Sent: Friday, April 21, 2006 7:10 AM
To: ev@listproc.sjsu.edu
Subject: RE: Albright Contactor rework
Dang, I've got two of these wired into my EV already, wired with 48V. I
don't have the facilities or expertise to rewind them, either. I wonder if
I should add a circuit to my KSI so that it won't all the contactors to
close until after the controller is precharged.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Neon John
Sent: Thursday, April 20, 2006 10:46 PM
To: ev@listproc.sjsu.edu
Subject: Albright Contactor rework
Y'all may remember the group purchase on the Albright SW200A-678
contactors with the 56 volt coils that was organized last year. I
bought 8 (and sure wish I'd bought more :-)
I finally got time today to take the solenoid apart and compute the
new winding for 12 volt nominal service. Following is an excerpt from
my shop log book detailing the work.
Before I did anything, I tested the contactor as-found. I was not
impressed. With almost 53 volts (48volt pack on trickle) on the coil,
the armature just sorta sidled into place. Not the snap that we
expect of a high current contactor. I tested a couple more just to
make sure I didn't get a fluke. I didn't. I could just imagine these
contacts gliding listlessly closed into non-pre-charged controller
capacitors. The fireball should be entertaining, at least.
This was an unsatisfactory condition so after poking around with a
dynamometer (in this context, a spring-scale-like device for measuring
force) to see just what kind of starting force was generated by the
solenoid, I decided to design for 4X the starting force. That meant
about 4X the ampere-turns as the original coil.
The frame of the solenoid is staked together during manufacture.
Disassembly required I grind off the stakes and carefully lever the
frame apart. Once the frame was apart, the blue outer plastic sleeve
came off easily after I unsoldered the wires (photos on my web site
later) to expose the windings. Fortunately these were random-wound
bobbins without any potting compound. What follows is from my log
book.
John
-----------------------
04/20/06
Stock coil ------------------------------
At 51.4 volts, 225ma flows, computing to 228 ohms
Ohmmeter measures 207 ohms cold. Two different meters agree. Probably
the difference between cold and hot ohms.
With 52 volts on the solenoid, the core temperature (looking down the
solenoid bore with an IR pyrometer) rose to 157 Deg. and stabilized.
The outer plastic temperature was 129 deg.
Modified Coil - 12 volt nom service ------
At Jerry's (electric motor) shop.
Unwound the spool on Jerry's winding machine and measured the wire
gauge more precisely after burning off the insulation. 5008 turns of
#29 wire.
Computed 1200 turns of #21 wire for 12 volts.
On the bench with 13.87 volts on the coil, the initial current was
2.153 amps. The temperature started rising rapidly. After an hour in
free air the outside temperature was 207 degrees and stable and the
current had dropped to 1.966 amps. (Ain't Boltzmann grand?) That
works out to a hot resistance of 13.87/1.966 = 7.055 ohms.
(This is Class H wire so the temperature isn't anything to get excited
about. The plastic bobbin is the limiting factor. It feels like some
sort of cheap filled polyethylene or maybe nylon.)
This is a bit hot, though it would work in the EV because that much
voltage will not be available at the coil terminals. I'm going to
shoot for 1.0 amps holding at 12 volts for the first try. That
indicates 12 ohms. A peak/hold driver consisting of a 4.7 ohm
resistor shunted by a 50k uf cap should do the job, giving a time
constant of 0.24 seconds. The 4.7 ohm resistor will need to be 5
watts at least. A 10 volt cap would work, though I'm going to use a
16 volt or greater for safety margin.
If less than 1 amp can hold the solenoid in then I'm going to try 0.75
amps and then 0.5 amp, trying for the least holding current that will
hold the solenoid in even over rough terrain. For 0.75 amps at 12.0
volts, I'll need 16 ohms total. With 7 ohms in the coil, 16-7= 9 ohms
series resistor, shunted by a 30kuf cap for about the same time
constant.
This time constant should give enough of a current pulse to hammer the
contactor closed, yet let the contactor cycle in less than half a
second if necessary. I'll probably use a standard 8 ohm sand resistor
from Rat Shack and let the light gauge hookup wiring supply the other
ohm.
The spool is too full for the blue cover to fit back on so I wrapped
the coil with Scotch 88 after dribbling some thin epoxy into the
turns. The spool is of too cheap a grade of plastic to dip and bake.
For the next coil I'll use 22ga wire which will be less filling and
will allow the blue spool cover to go back on.
---- NOTE -----
These calculations are for ordinary enameled coil winding wire and NOT
Inverter-Grade wire. IG wire has a heavier insulation so the fill
factor is larger and fewer turns will fit.
To do:
* wind another coil with 22 ga wire.
* fit an LVDT to the armature and scope the contact motion.
* Test at 0.5 and 0.75 amps holding current.
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
--- Begin Message ---
On Fri, 21 Apr 2006 08:15:18 -0700 (PDT), Mark Hastings
<[EMAIL PROTECTED]> wrote:
>I am only an hour away so I may go check it out.. If I was smaller I'd be more
>excited but I'm about 6'4" so it might be a no go anyhow. I'd like to think
>you could put more the just 4 optimas in it and something with more muscle
>then an etek. This might make a good candidate for my wifes commute, 3 round
>trip miles, in the rain. She likes to walk but it there is no where to walk or
>ride a bike on the roads in between.
I'm 6'7" and could sit easily in the 600. An amazing amount of leg
room. My height is fairly well balanced (my belt is about in the
middle :-) so if you're long-legged or long-torso'd you might have a
challenge.
I just don't see an ETEK doing the job here. Here are some specs.
http://www.greenspeed.us/electric_scooter_e-tek_motor.htm
It's only rated at 150 amps continuous and 300 amps for 30 seconds.
I'd consider that the absolute max rating, not to be exceeded for even
a couple more seconds.
The problem with the ETEK is that the iron-less armature has no
thermal mass so it can't sustain large overloads like conventional
motors can. Several people have described on this list how to
unsolder armature bars by trying to push the envelope :-(
That 600 would be about the size and weight of a CitiCar. The Citi
motor is 3hp nominal - about the same rating as the ETEK. But I can
hammer it with >450 amps with the controller bypass and it doesn't
whimper. OTOH, motor current stays >300 amps for much of the time
while driving in town, stop and go.
You'll simply need more motor. I've been doing some figuring
regarding the idea of using 2 ETEKs on my Citi. I think they'd
perform nicely. I have the two motors. What I need now is a spare
Citi motor that I can gut, cut down the frame and use to host a cog
belt pulley. I'm planning on connecting the two ETEKs to the stock
diff with a cog belt.
I started to try one ETEK but back-of-the-matchbook cals say it just
won't live in that environment.
If I were going to try to convert a 600, I'd go with at least 72
volts. Scatter the batteries on the 4 corners near the suspension
attachment points. For the short mileage you're talking about, 30ah
hawkers would do the job and be lighter than the Optimas, though more
costly.
I'd use an Alltrax 7245 controller (72 volts, 450 amps max) and gear
the two ETEKs for perhaps 60 volts at full speed. (and set the
controller accordingly). That's more than the ETEK is spec'd for but
I think it will be OK and live longer than lower RPM and higher
current.
I'm having trouble pulling the image of the transmission out of my old
memory but I think I remember it being essentially the Honda 450
motorcycle transmission in a different case, set up for FWD. If so,
it's a highly efficient dog-type transmission, much superior to
syncromesh car transmissions. I'd definitely try to use it even if
you have to carve away some of the cases and weld in cover plates.
That transmission could be used effectively to keep the ETEK's RPM up
and the current draw down. If you go that route, let me know and I'll
give you some racing tips to cut down the transmission losses even
more.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
--- Begin Message ---
I'll answer anyway since neon is one of my "things" :-) A glow
discharge lamp doesn't have a "voltage rating". It has a strike
voltage, eg, the voltage at which it will fire, and an operating
current. Once the discharge starts, the lamp acts as a negative
resistance device where the voltage drop actually decreases with
increasing current. The purpose of the ballast resistor is to limit
this current to the specified value.
An NE-2 will strike at something like 140 volts and then operate at
the specified current at somewhere in the range of 40-60 volts.
But that's not all the story. Something has to cause the strike to
start, to cause the initial ionization. That can be a random
ionization, a cosmic ray, a radioactive decay or light striking the
electrodes. Traditionally, a little radioactive Thorium was included
in the electrode material to stabilize the strike voltage. Most
modern manufacture bulbs now have a little Kr-85 radioactive gas in
the fill.
Light impingement is still a problem for applications where the strike
voltage is important. Everyone has probably seen an outlet strip with
a dying neon pilot lamp where the lamp will burn or flicker when the
room lights are on but go out in the dark (about the opposite of what
a pilot light should do :-) That's the photoelectric effect at work -
the ambient light provides just enough extra kick to get the
ionization going.
There are (or at least used to be) special purpose neon bulbs designed
for stable strike voltages. This usually involves a little more
radioactive gas and more precise control of the electrode spacing.
Bulbs can also be had with strike voltages up in the hundreds. The
cheap strobe light such as used in disposable cameras contain this
sort of lamp. Typical strike voltage is 350-400 volts, depending on
the strobe design.
I've noticed that the argon/phosphor lamps, those that glow green or
blue or sometimes yellow, have more stable strike voltages than plain
neon. One reason is that argon is much more easily ionized. Another
is that the phosphor coating inside the glass envelope shields the gas
from ambient light.
Neon lamps will work OK on DC but only one of the electrodes will
light. The strike voltage tends to be more variable because there
isn't the slight dV/dT effect across the electrodes on each half-cycle
that helps start the ionization when operated on AC.
In any event, you'll need a ballast resistor to limit the operating
current once the lamp strikes - just like on AC. Here's the first
spec sheet Google found for "ne2 specification sheet".
http://www.donsbulbs.com/cgi-bin/r/b.pl/neon%7Cne2~usa.html
Looks like the bulb needs between 1 and 3ma to achieve its rated life.
3ma will be REAL bright so I'd shoot for the low end, perhaps a little
less than 1 ma unless direct sunlight is involved.
To put that current in perspective, standard neon signs run on 24ma.
Those small neon sculptures that you can buy at Wallyworld and the
like use from 4 to 10ma, usually toward the lower end. When I do
indoor custom neon for people, unless they want to use the neon for
illumination, I usually cut the current down to between 1 and 5ma so
the glare isn't so bad. A few ma go a long ways!
John
On Fri, 21 Apr 2006 09:22:00 -0600, "Bill Dennis" <[EMAIL PROTECTED]>
wrote:
>How do the voltage ratings on neon lamps work? If a lamps says that its
>voltage rating is 120V, does this mean that it won't turn on until 120V, or
>that it should never be connected to more than 120V?
>
>If it means that the lamp won't turn on until 120V, then how firm is that
>number? Will it be passing some current at 109V or 117V, but not be passing
>full current until 120V? Or will it be passing no current at all until
>120V?
>
>Finally, if it means that it won't turn on until 120V, then how do you
>determine the upper range (e.g., with a 120V pack, will the lamp be okay at
>a fully-charged 160V)?
>
>Thanks.
>
>Bill Dennis
>
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
Don't let your schooling interfere with your education-Mark Twain
--- End Message ---
