Neon AC compressor cycling

None on auto AC in particular, but a far bit on AC in general in my
thermodynamics courses.

I don't need to be an auto AC repairman to operate an auto AC system and
read an owner's manual.


Matt

 

I didn't say you were a pig. You obviously aren't familiar with that
saying.

You don't need to tap the circuit to have a voltage divider. The
voltage is divided whether you measure it or not. This is the same as
the tree falling in the forest scenario. Just because nobody is there
to hear it doesn't mean it didn't make a noise.


Matt

 

I'm never absolutely certain about anything as there are almost always
exceptions. I'm pretty certain I've read that in owner's manuals for
cars I've owned, but my current cars don't say that. However, the
Caravan refers to the exact same phenomenon in the context of
preparation for storage. Other than lacking the word "winter" which you
are so hung up on, it is saying exactly what I said and for exactly the
reason I said it. Do you dispute that?

If you can tell me that there is a difference between not running the AC
all winter and then cranking it up in the spring, and not running the
car for a few weeks and then cranking it up, I'll concede that you were
right and I was wrong and lubrication of the compressor isn't a valid
reason to periodically run the compressor.


Matt

 

No, it is just that I haven't owned every car model that was ever made.

It is the same because in neither case is the compressor running. If
not running the compressor for long periods of time poses a potential
for damage to the compressor from lack of lubrication, then how does the
compressor know why it wasn't being run?


Matt

 

Wrong on all counts? Hardly. The only "count" was that winter wasn't
specifically mentioned. However running the compressor periodically to
keep it lubricated was mentioned and that was the essence of my initial
comment. Still trying to twist the words to support your claim, eh?

What is the one exception?

Likewise, I'm having a hoot reading your attempts to claim we said
things we didn't.


Matt

 

Well, you can always pick a GOOD example to support your claim that it
remains constantly cold for months on end...


Matt

 

I think it was carburetor ice.

Matt

 

OK, I'm convinced...your ignant!!

 

So you are admitting you know squat??[/QUOTE]

No clara, I'm say that by the time I started working as a
mechanic in 1970, most of these types of vehicles had gone on the
the great junkyard in the sky because they rusted out from the
amount of road salt used in this region.

Gee, 50 years old is young huh? Seems to me that there is all of
about 4 years difference in the length of our careers, difference
being, I can and do still do it and make a good living at it, you
on the other hand fall into the "I used to" category.

Mechanic? Hardly. Parts changer? No doubt. But thanks for
including the "I was" as further proof of what I mentioned above.

Then one can only surmise that your lack of knowledge on VW
carburetor anti-icing devices is equal to those that Dan Stern
cited about ChryCo products.

 

I thought it was due to ice build up on the windows of the bridge because
Capt. Neil had disconnected the AC compressor during the winter months :0)

 

Well you have just proven you have no clue as to how the system works, or
what causes condensation.
But, then even if you did know you probably would not say as I have pegged
you as a common troll at this point.

 

Another way to look at it is that the coil acts as both the lower
element of the voltage divider to cause the current flow that drops (yes
- I said "drops") the voltage across the ballast resistor *AND* as the
element that is tied to the junction (that non-existent tap) that
utilizes that reduced (dare I say it: divided) voltage. Probably too
complicate for *certain* people to understand, no doubt.

Matt - It's very clear that what Neil needs to do is to find the ballast
resistor terminal on the coil and add a wire to it (he could just leave
it dangling or tape it off), and to put a piece of masking tape on that
wire and write the word "tap" on the masking tape. *THEN* he can't say
that there is no tap on the voltage divider formed by the ballast
resistor and the coil. All conditions of the articles will have then
been met to call it a voltage divider. And like magic, if you rip that
added wire from the junction, the whole thing suddenly ceases to be a
voltage divider! And yet the circuit won't know the difference, and the
coil will continue to function as always with the
reduced/dropped/divided voltage. Amazing that it doesn't realize that
it is no longer a voltage divider, yet it keeps dividing the voltage and
still functions exactly the same with or without the "tap"! To quote
Mel Brooks: "Woof!"

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Oh belive me Matt - it knows! Just like the ballast resistor-coil
circuit knows whether or not there's a wire called a tap at the junction
and decides from that whether to act like a voltage divider or not. 8^)

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Do flying Subarus count? Here's a photo of one:
http://www.kiwisport.net/4images/details.php?image_id=31&sessionid=8449646742b3a9cf1a07b2f10ccb6d4d

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

You are absolutely, right. How silly of me to miss this obvious
analogy!

Well, it's been fun, but I'm getting tired of typing. However, I'm
really hoping to see the GOOD example of a place in the lower 48 that
has months on end of average temperatures below 30 or even 25 F.

I'm certain that northern Alaska meets this requirement most likely, but
I'll bet there aren't many other places, if any, that have 3 or more
months of temperatures that are "continually" or "constantly" below 25.
There's one place in Minnesota that might qualify as it always seems
to be the cold point in the USA on the Weather Channel.


Matt

 

Nope, gotta be a Neon, no exceptions!


Matt

 

PCM, I hate to burst your balloon, but everything Neil's said in this
thread has been smack on the money as far as theory and practice goes.
Much of what you've posted has been technically OK, but you seem to be
weirdly grabbing bits and parts of multiple salient points and
modging them together, then arguing against the concatenation. That is
known as "straw man" argumentation.

-DS

 

A voltmeter is installed in PARALLEL and voltage is equal in all
branches of a parallel circuit, so no voltage divider exists.[/QUOTE]

So, you're saying I'm wrong?

 

Yes, that is obvious. Glad you were finally able to pick up on an
obvious point. It should be also equally obvious to you that not
running the compressor for two weeks or longer in the off season is
equivalent to "storing" the car for two weeks or longer while on
vacation. Is this really that hard of a concept for you to grasp?[/QUOTE]

No, the concept is not hard for me to understand, but apparently
the reason that they recommend doing this on a minivan has totaly
escaped you.

You're the one who interjected being a "pilot" into this.
I'm trying to get you to explain why conditions that might exist
at altitude that would be conducive to cloud formation and
airframe icing are relevant to a vehicle driven at ground level.

If anyone's dodging, it's you.

Or; you're not a pilot and you haven't a clue WRT air density and
the mechanics that can and do occur when it varies.

 

So, you're saying I'm wrong?[/QUOTE]

Actually if you're saying that a voltmeter across a battery is a voltage
divider, you are technically correct.

Here's why: The battery has an internal resistance. Also, the voltmeter
has a leakage on its input terminals also represented as a resistance.

The difference between the two resistances is several orders of
magnitude - we're talking the difference between maybe less than an ohm
for the battery and 1000 Megaohms for the meter (1000,000,000) and
that's the minimum guaranteed - in actuallity, the meter may actually be
10 to 100 times better than that.

You can plug those numbers into the voltage divider formula (battery
resistance being the "top" resistor, meter resistance being the bottom
resistor). What you'll find is that, if the battery measures exactly
12.000000000 volts (round numbers make the illustration easier), when
you put the meter on it, you may find that the meter pulls it down to
and reads 11.999999995 volts, except the accuracy and resolution of the
meter would not show that effect in a million years.

But yes - you are technically correct - that is a voltage divider.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")