Hi guys,
Maybe you could bring me up to speed on this. you need a 36 to 14V
converter for what motor?
Just a couple of observations, going from 36 to 14 or 36 to any
voltage, is basically what motor controllers do, they just do it to
any voltage you select which equates to motor rpms and torque. If
there's one thing I noticed on the ET's is that this is an area
that needs some work. First, I want to get as much out of the
batteries as possible, running a toaster resistor was a great and
bullet proof solution in 1960 but today's electronics it's not the
best idea.
Best,
Rob
ps: I got an email back from the engineers at Intersil, it looks
like the HIP4081A is going to be the drive chip for my controller.
-----Original Message----- From:
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Today's Topics:
1. Re: 36 to 14 volt DC-DC converter (was Today's lessons with
heavy snow) (Charlie)
2. Re: 36 to 14 volt DC-DC converter (was Today's lessons with
heavy snow) (RJ Kanary)
3. Re: 36 to 14 volt DC-DC converter (was Today's lessons with
heavy snow) (David Roden (Akron OH USA))
4. Re: 36 to 14 volt DC-DC converter (was Today's lessons with
heavy snow) (RJ Kanary)
5. Re: 36 to 14 volt DC-DC converter (was Today's lessons with
heavy snow) (The CZ Unit)
----------------------------------------------------------------------
Message: 1
Date: Wed, 2 Jan 2013 12:23:07 -0500
From: Charlie mailto:medievalist gmail com
To: Elec-Trak mailto:elec-trak cosmos phy tufts edu
Subject: Re: (ET) 36 to 14 volt DC-DC converter (was Today's lessons
with heavy snow)
Message-ID:
mailto:CAJb3uA7jYexv5ghRpidcWWE8z85zxms1nEDY5qf6jZqOHL9Ryg mail gmail com
Content-Type: text/plain; charset=ISO-8859-1
You're going to laugh, but what I want is a bolt-in, solid-state
replacement for the "toaster" that can handle 500 Amps at 36VDC.
According to the circuit designers I've consulted, it's actually
theoretically possible to make a high-current device that throttles
the juice (rather than just blowing off a portion of it as heat) but
it's really not at all cost effective when you consider the price of
electricity and the immense durability of the stock toaster.
Yeah, I said you'd laugh, now didn't I?
--Charlie
On Sat, Dec 22, 2012 at 5:18 PM, Darryl McMahon
mailto:darryl econogics com wrote:
I have looked for a 36-volt nominal input to 14.2 volts regulated
and steady
output device for years, which is expected to survive more than
one use and
be in the affordable range (under $150 retail). Never found one.
I figure
there are plenty of automotive 12-volt devices I would like to run
from the
whole pack - like winches, lighting, horns, etc.
My son the electronics tech says this is an easy unit to design
and build.
However, he figures if he goes to the trouble of designing and
testing one,
we should be looking to make a few to justify the effort. His
question is,
what current rating is required(on the output side)? I have
struggled with
that one. Price goes up with power handling. It's stepwise based on
components, so not quite linear (power/cost). The winch I am
using seems to
pull about 15 amps. I would likely rewire my original lifts to
the 14 volts
from the sagging 18 to extend their life. Lighting will likely be
a pretty
small load (thanks to LEDs).
So, is anybody else interested in a 36 nom to 14.2 regulated volts
DC-DC
converter (fully isolated - 2 leads in, 2 leads out), and if so, what
current (output) would you consider desirable? If there is any
response, I
will chat over the information provided with him over the holidays
and see
what we can come up with. (I already know he'll say we don't need
any new
projects - but my response is that we have been talking about this
for so
long it's an old project <smile>.)
Darryl McMahon
On 22/12/2012 4:15 PM, The CZ Unit wrote:
On 12/22/2012 11:30 AM, Chris Tromley wrote:
For the lift, how big a deal is it to just run it on 36V? If it
only
runs for a few seconds at a time and has plenty of cool-off
time, why
would it hurt? If it is a problem, I wonder if you could use a
cheapo
off-the-shelf scooter controller?
Honestly? I don't know. It probably would be ok, the problem is
the lift
current breaker would probably fuse instantly if it tried to open
due to
overload, that would be a problem.
Hm. Actually I have a bunch of apart-lift motors, I'll give it an
honest
shot. The question is how do we current-limit it so the overload can
work? Maybe bypass it completely and use a 5 amp circuit breaker
instead
of a fuse? What would be a good auto-reset 5-10 amp circuit breaker?
How common are 36V-to-12V DC/DC converters that would be
suitable for
the lights? Are there any 48V input models that would still
work with a
sagging 36V pack?
I used to use a Vicor DC-DC that would put out 12 volts for the um
E-meter and lights. But one morning I came out and found it had
literally blown up, which was odd. Might have been over-voltaged,
but it
should have been able to handle up to 50 volts input.
Where I really need to limit current is on the sweeper. The motor on
that is just too darn fast, it beats up the brushes and the
grass. Maybe
I could get a much smaller pulley or something.
_______________________________________________
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------------------------------
Message: 2
Date: Wed, 02 Jan 2013 13:55:03 -0500
From: RJ Kanary mailto:rjkanary consolidated net
To: Charlie mailto:medievalist gmail com, et
mailto:Elec-trak cosmos phy tufts edu
Subject: Re: (ET) 36 to 14 volt DC-DC converter (was Today's lessons
with heavy snow)
Message-ID: mailto:50E48287 4090607 consolidated net
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
These kind of observations give me an ear to ear grin.You have
the braintrust that was the OPEO,using technology firmly rooted in the
Forties,using the pencils, papers and sliderules for the basis of
their engineering and design decisions, that 21st Century technology
has yet to better in a cost effective manner. <VBG>
RJ
On 1/2/2013 12:23 PM, Charlie wrote:
You're going to laugh, but what I want is a bolt-in, solid-state
replacement for the "toaster" that can handle 500 Amps at 36VDC.
According to the circuit designers I've consulted, it's actually
theoretically possible to make a high-current device that throttles
the juice (rather than just blowing off a portion of it as heat) but
it's really not at all cost effective when you consider the price of
electricity and the immense durability of the stock toaster.
Yeah, I said you'd laugh, now didn't I?
--Charlie
On Sat, Dec 22, 2012 at 5:18 PM, Darryl McMahon
mailto:darryl econogics com wrote:
I have looked for a 36-volt nominal input to 14.2 volts regulated
and steady
output device for years, which is expected to survive more than
one use and
be in the affordable range (under $150 retail). Never found
one. I figure
there are plenty of automotive 12-volt devices I would like to
run from the
whole pack - like winches, lighting, horns, etc.
My son the electronics tech says this is an easy unit to design
and build.
However, he figures if he goes to the trouble of designing and
testing one,
we should be looking to make a few to justify the effort. His
question is,
what current rating is required(on the output side)? I have
struggled with
that one. Price goes up with power handling. It's stepwise
based on
components, so not quite linear (power/cost). The winch I am
using seems to
pull about 15 amps. I would likely rewire my original lifts to
the 14 volts
from the sagging 18 to extend their life. Lighting will likely
be a pretty
small load (thanks to LEDs).
So, is anybody else interested in a 36 nom to 14.2 regulated
volts DC-DC
converter (fully isolated - 2 leads in, 2 leads out), and if so,
what
current (output) would you consider desirable? If there is any
response, I
will chat over the information provided with him over the
holidays and see
what we can come up with. (I already know he'll say we don't
need any new
projects - but my response is that we have been talking about
this for so
long it's an old project <smile>.)
Darryl McMahon
On 22/12/2012 4:15 PM, The CZ Unit wrote:
On 12/22/2012 11:30 AM, Chris Tromley wrote:
For the lift, how big a deal is it to just run it on 36V? If
it only
runs for a few seconds at a time and has plenty of cool-off
time, why
would it hurt? If it is a problem, I wonder if you could use a
cheapo
off-the-shelf scooter controller?
Honestly? I don't know. It probably would be ok, the problem is
the lift
current breaker would probably fuse instantly if it tried to
open due to
overload, that would be a problem.
Hm. Actually I have a bunch of apart-lift motors, I'll give it
an honest
shot. The question is how do we current-limit it so the overload
can
work? Maybe bypass it completely and use a 5 amp circuit breaker
instead
of a fuse? What would be a good auto-reset 5-10 amp circuit
breaker?
How common are 36V-to-12V DC/DC converters that would be
suitable for
the lights? Are there any 48V input models that would still
work with a
sagging 36V pack?
I used to use a Vicor DC-DC that would put out 12 volts for the um
E-meter and lights. But one morning I came out and found it had
literally blown up, which was odd. Might have been
over-voltaged, but it
should have been able to handle up to 50 volts input.
Where I really need to limit current is on the sweeper. The
motor on
that is just too darn fast, it beats up the brushes and the
grass. Maybe
I could get a much smaller pulley or something.
_______________________________________________
Elec-trak mailing list
Elec-trak cosmos phy tufts edu
https://cosmos.phy.tufts.edu/mailman/listinfo.cgi/elec-trak
_______________________________________________
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------------------------------
Message: 3
Date: Wed, 02 Jan 2013 14:48:02 -0500
From: "David Roden (Akron OH USA)" mailto:etpost drmm net
To: Elec-trak cosmos phy tufts edu
Subject: Re: (ET) 36 to 14 volt DC-DC converter (was Today's lessons
with heavy snow)
Message-ID: mailto:50E448A2 17838 40120473 etpost drmm net
On 2 Jan 2013 at 13:55, RJ Kanary wrote:
You have the braintrust that was the OPEO,using technology firmly
rooted in the Forties,using the pencils, papers and sliderules for
the
basis of their engineering and design decisions, that 21st Century
technology has yet to better in a cost effective manner. <VBG>
I don't know what OPEO is, but I disagree that recent years have
brought no
significant improvement.
I've used the GE controller, I've used an equally simplistic
series-parallel-
and-resistor 3-step controller in another EV, and I've used several
good
solid state controllers. There's absolutely no doubt in my mind
that late
20th / early 21st century technology is far superior. True, the
cost is a
bit higher, but for me it's worth it.
The GE controller is easy to work on, I'll say that. Good thing,
because
when I had it, I worked on it A LOT - control card, connections, and
especially that bloody reversing relay. Ah, memories : plowing the
driveway
with the hood up and the relay panel tipped back, reversing the
tractor by
pushing on the relay.
I spent an afternoon rewiring the ET for my Alltrax, and since then
I've had
zero control problems. (Well, OK, I did have to replace the crummy
cheap
reversing switch I used, but that was my own fault for grabbing a
used Radio
Shack special from my junkbox.)
I can also move the tractor by centimeters in any gear, and choose the
prefect speed for any job. The controller will even hold my ET
steady all
by itself on a hill, if I'm so inclined, though I don't usually let
it do
that because I don't think it's healthy for the motor.
The good news is that there are plenty of spares for maintaining
the good
old GE click-clicker if you're so inclined, and there are also decent
options for modernizing if that's your preference. We're really
fortunate
that there's such a vital community supporting these tractors.
------------------------------
Message: 4
Date: Wed, 02 Jan 2013 15:22:39 -0500
From: RJ Kanary mailto:rjkanary consolidated net
To: "David Roden (Akron OH USA)" mailto:etpost drmm net, et
mailto:Elec-trak cosmos phy tufts edu
Subject: Re: (ET) 36 to 14 volt DC-DC converter (was Today's lessons
with heavy snow)
Message-ID: mailto:50E4970F 6080007 consolidated net
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
O utdoor
P ower
E quipment
O peration
The folks that designed and produced these tractors.
My observation applied directly to the application mentioned in the
original post.Reliable efficient ,inexpensive control for that
application is apparently only constructed from Unobtanium. :)
It appears that you were victimized by the Field Reversing
scheme that was in vogue during the E-12 S and the early
E-15.Obviously an idea that was not well thought out, and poorly
executed.Even a guy that fixed cars and trucks for a living could see
that was a good one to repair, but not a good one to own.
{Unless the later armature reversed controls were
installed.}<VBG>
Funny, they got it RIGHT on the E-20 since Day One.
TheApollo Era controls have no potted boxes of mystery nor any
IC that will likely fall out of favor and become unavailable long
before the clicky-clack control parts are all dried up.There is very
little evidence of the 'throw-away society' idea being used in the
planning and execution of the original product.Solid state devices? A
different time, a different mind set.
But, this is all one disabled Luddite's observation, not to be taken
as Gospel. A third generation remnant of a family that has been
repairing electrical and electronics contrivances since the dawn of
commercial broadcast radio.
[And I STILL ended up fixing cars and trucks.]
On 1/2/2013 2:48 PM, David Roden (Akron OH USA) wrote:
On 2 Jan 2013 at 13:55, RJ Kanary wrote:
You have the braintrust that was the OPEO,using technology firmly
rooted in the Forties,using the pencils, papers and sliderules
for the
basis of their engineering and design decisions, that 21st Century
technology has yet to better in a cost effective manner. <VBG>
I don't know what OPEO is, but I disagree that recent years have
brought no
significant improvement.
I've used the GE controller, I've used an equally simplistic
series-parallel-
and-resistor 3-step controller in another EV, and I've used
several good
solid state controllers. There's absolutely no doubt in my mind
that late
20th / early 21st century technology is far superior. True, the
cost is a
bit higher, but for me it's worth it.
The GE controller is easy to work on, I'll say that. Good thing,
because
when I had it, I worked on it A LOT - control card, connections, and
especially that bloody reversing relay. Ah, memories : plowing
the driveway
with the hood up and the relay panel tipped back, reversing the
tractor by
pushing on the relay.
I spent an afternoon rewiring the ET for my Alltrax, and since
then I've had
zero control problems. (Well, OK, I did have to replace the
crummy cheap
reversing switch I used, but that was my own fault for grabbing a
used Radio
Shack special from my junkbox.)
I can also move the tractor by centimeters in any gear, and choose
the
prefect speed for any job. The controller will even hold my ET
steady all
by itself on a hill, if I'm so inclined, though I don't usually
let it do
that because I don't think it's healthy for the motor.
The good news is that there are plenty of spares for maintaining
the good
old GE click-clicker if you're so inclined, and there are also decent
options for modernizing if that's your preference. We're really
fortunate
that there's such a vital community supporting these tractors.
_______________________________________________
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Elec-trak cosmos phy tufts edu
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------------------------------
Message: 5
Date: Wed, 02 Jan 2013 22:12:04 -0500
From: The CZ Unit mailto:cz alembic crystel com
To: elec-trak cosmos phy tufts edu
Subject: Re: (ET) 36 to 14 volt DC-DC converter (was Today's lessons
with heavy snow)
Message-ID: mailto:50E4F704 8050909 alembic crystel com
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
On 1/2/2013 3:22 PM, RJ Kanary wrote:
It appears that you were victimized by the Field Reversing
scheme that was in vogue during the E-12 S and the early
E-15.Obviously
an idea that was not well thought out, and poorly executed.Even a guy
that fixed cars and trucks for a living could see that was a good
one to
repair, but not a good one to own.
I have to agree. My first Elec-trak was an E20 and it's been pretty
much
indestructible in terms of controller. The only problem was when
one of
the field diodes failed, cost a few bucks to replace all four
diodes on
card 4. And after 10 years of service I noticed the contactors for F
were getting warm, so I simply flipped the contactors over and now
I can
run on the R ones for another 40 years or so.
The E15 is more of a fickle thing, the concept of reversing the field
was cheaper to implement, but the result was a very annoying
tendency to
blow out the relay if the MOV is bad and you go from F to R
quickly. New
MOVs seem to make the problem go away but I'm guessing they blow up
eventually.
Putting in E20 style reversing contactors would be the right way to
go;
I might just do it. But I like the standard speeds, quick performance,
and simple reliability of the E20 system.
Chris
------------------------------
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