From: John De Armond
Newsgroups: alt.pop-up-trailers,alt.rv.pop-up-trailers,rec.outdoors.rv-travel
Subject: Re: Electric Brake Controller
Date: Sat, 22 Nov 2003 23:03:02 -0500
Message-ID: <rbb0svs8jst6ge1kdgk4kk1i865qgpve5a@4ax.com>

On Sat, 22 Nov 2003 21:21:49 GMT, "AustinMN" <Xtacooper260X@hotmail.com>
wrote:


>> Carl
>
>I have no experience, but this looks like a piece of junk to me.

Ya just gotta love that kind of logic...


>From the web site:
>"The hand held actuator controller plugs into the cigarette lighter
>and sends signals through existing vehicle wiring to the actuator,
>providing adjustments to match load and road conditions."
>
>Hand Held???? You've got to be kidding.  The only thing I'm
>hand-holding in a panic stop is the steering wheel...with both hands.

Did you actually bother to look at the controller?  Its purpose is to tune the
system to match the system to different conditions and to manually actuate the
trailer brakes - the same functions many other controllers have.  Panic
stopping has nothing to do with the controller.  Manual actuation IS handy to
help damp oscillations (sway) so it's nice to have one at hand.  Unless you
just enjoy the jackknife experience, you really should not be operating the
tow vehicle brakes during a sway excursion.


>From the web site:
>"The Carlisle actuator is powered by a trailer mounted battery which
>is charged thanks to the battery charger built into the actuator.
>Power for the built-in battery charger is drawn from the tow vehicle's
>running light circuit. Therefore, the tow vehicle's running lights
>need to be on whenever the trailer is being towed."
>
>This sounds like propping the tree on both sides to hold it up, then
>cutting it off at the trunk.
>
>It's difficult to get a battery to charge using a dedicated charge
>line, never mind stealing power from the running lights, which have a
>fuse that would prevent the charge circuit from doing much charging,
>at least without blowing the fuse.  I wouldn't be surprised if the
>running lights are down by 1.5 volts or more before putting this
>charge circuit on it.  Oh, I'm sure that will work.

IT is apparent that you don't understand the purpose of this controller.  It
fills the niche where a trailer may be towed by a variety of vehicles, none of
which need be set up with brake controllers.  A typical example might be a
Coke concession trailer that is loaned or rented to customers.  It would be
fairly impractical to expect every customer tow vehicle to contain a brake
controller.  With this unit, one need simply plug in the trailer lights, plug
in the remote controller and drive away.

As for charging the battery from the running lights, I hope you can comprehend
that there are ways other than a simple wire connection to achieve this.
Specifically the buck/boost switching regulator.  This simple circuit can
boost the incoming voltage to any desired level and then regulate it.  It
takes a purpose-designed IC and a half dozen components.  I have several such
devices that I designed for the purpose of keeping my start packs fully
charged.  My circuit will accept anything from about 8 volts to around 40
volts on the input and output a precisely regulated voltage, in this case 13.8
volts at 70 degrees.

Since Dallas Semi, On Semi and several other companies make chips especially
for this type of application, since they publish example application designs
and since I bet a big company like Carlisle has a few engineers hanging
around, I imagine their controller contains just this type of circuit.  I've
always found it useful to accept a company's word on things like this until I
have proof otherwise.  Saves on that very unpleasant task of eating crow.

This looks like a slick product, one I'm going to take a very close look at
for my concession trailer, since it may be towed by any number of people who
rent it on occasion.  Thanks to the original poster for finding the products
and posting about it.

John

From: John De Armond
Newsgroups: alt.pop-up-trailers,alt.rv.pop-up-trailers,rec.outdoors.rv-travel
Subject: Re: Electric Brake Controller
Date: Mon, 24 Nov 2003 17:54:20 -0500
Message-ID: <dvn4svscu3iu55ekm3d28bfcor47ecr7l6@4ax.com>

On Mon, 24 Nov 2003 18:02:48 GMT, "AustinMN" <Xtacooper260X@hotmail.com>
wrote:

>Think for a moment...in a panic stop, what happens to loose items in
>your tow vehicle?  They go flying all over.  This controller would end
>up on the passenger side floor unplugged at the moment it is most
>needed.

I suppose that if you're that incompetent or careless, then you should Velcro
or stickypad the controller to the dash.

So tell me, in your panic stop situation, do you think you'd find it any
easier to reach down between your legs and under the dash to reach your
permanently mounted controller?  Ya, right.


>I can understand that application, but unless the OP has more than two
>tow vehicles, it would be cheaper to buy a controller for each
>vehicle.  Never mind that he could buy one controller with a mount for
>each vehicle...for about $10 per vehicle.

I didn't realize cheapness had entered this discussion.  I can't imagine
anyone actually porting a controller from one vehicle to another.  My time's
worth more than that.


>I once worked QA for what was the largest manufaturer of DC to DC
>converters in the world.

So YOU'RE the guy who applies those "inspected by #2" stamps.  I'd always
wondered about that.

>And I know that although DC/DC converters
>could be made for as little as $10 each, that the least it could be
>done for the consumer market was about $75...UL/CSA listings, etc.
>make a huge difference.  I have seen this process eat up hundreds of
>thousands of dollars and result in a doubling of materials cost.

If I actually believed that you knew what you were talking about I'd comment
on the incompetency of a company that could spend those kinds of dollars on a
consumer grade converter.  But that would be unfair to the company.

I should point out to you that any day of the week I can walk into a Norther
Tool store and buy a Vector 80 watt inverter for $22.  That is in fact a DC-DC
converter with a 60 hz switching output stage added on.  This unit has the
additional certification requirements that go with a high voltage consumer
device.  Yet somehow Northern makes a profit at $22.  Hmmmm.

Frankly if I couldn't bring in a non-military grade buck/boost regulator for
under $2 I'd hang up my engineer's hat.  I should point out that in the device
we're discussing the battery charging is a component function of the device.
I'd not be surprised to discover that the microprocessor controls the charging
in the background.  In any event that functionality does not require agency
approval.  The brake controller device as a whole is qualified, not each
internal part of the assembly.

>
>I also know that switching regulators draw more current as the input
>voltage drops.  As the current rises, it causes additional voltage
>drop...and when the runaway is done, most likely a blown fuse on the
>running lights.

Let me introduce a few new terms to your lexicon.  "current limiting" "low
power" "low voltage cutoff".  Any converter capable of going into runaway is
simply wrong.  Since current limiting is inherent to most any IC based design,
I'd have to give some thought about how to design one that would run away.

>
>>
>> This looks like a slick product, one I'm going to take a very close
>> look at for my concession trailer, since it may be towed by any number
>> of people who rent it on occasion.  Thanks to the original poster for
>> finding the products and posting about it.
>
>Better check with a lawyer before loaning/renting/leasing it out.
>What would your liability be if the unthinkable happened because the
>controller plug fell out of the cigarette lighter?  Believe me, that's
>not something to bet your or anyone else's life on.

You still don't have any idea how this thing works, do you?  Why don't you
actually read that web site for the first time.  The brake controller, the
part that mounts on the trailer, is self-contained and autonomous, including
the power source and the accelerometer.  It neither requires nor needs the
manual hand controller.  The hand controller is for tuning and for manual
actuation.  Nothing else. Take the hand controller loose and toss it out the
window and the trailer brake controller still works.  Duh.

I find it particularly ironic that you declared it junk in your first post and
yet you don't even know how it works.

Oh, and if you'd been paying attention you'd know that I'm a small businessman
who is in the business of selling and renting things.  I know a thing or two
about that business, including how much and what kind of insurance to buy.

John