Why don't my LTI AF Horns Work, Part 2

Why don't my LTI AF Horns Work, Part 2

Post by Rich Sprit » Mon, 31 Jul 1995 04:00:00



Well folks, I tried a few things.  Just to review, all of my LTI AF
horns give a few blasts using a Gilbert AF Air Chime Whistle Controller
hooked up to my 30B transformers, then nada.  Unless I wait about 30
minutes, then I'll get a couple more blasts if I try, then nada.  And
the ringing bells basically don't work at all.  Ditto, the LTI horn
control doesn't work at all with my 30B.  

Anyway, I tried a D-cell in parallel (it would have to be in parallel);
I think the battery would blow up if you tried to run 15VAC through it),
and nada.

Next I tried a 9V battery, again in parallel.  That worked in one
polarity (I forget which) but not the other, but again only for a few
blasts, then nothing.  And then if I tried the Air Chime Whistle
Controller, nothing. And the 9V battery got almost too hot to hold in
about 30 seconds or less (remember, the loco was running, so it was in
parallel to 15 VAC).  My conclusions are that 1 and a half VDC is not
enough to fire the horn circuit, and that the problem is in the horn
circuit, not in the transformer, as many of you suggested.  That is
consistent with the fact that the horns don't work any better off my 19B.
Also, remember that all of my LTI horn locos do this, not just one,
so the problem is endemic to the mating of an LTI horn circuit to
an AF transformer.

Anyway, anybody have any more suggestions?  I'll be in Switzerland for

don't post them here.

Thanks in advance.

Rich

 
 
 

Why don't my LTI AF Horns Work, Part 2

Post by Thomas E. Doyl » Tue, 01 Aug 1995 04:00:00


If you parallel a DC voltage source (battery) with an AC voltage
source you will have problems. There will be a high current between
the two sources. If you want to superimpose a DC voltage on an AC
voltage - put the two sources in series. The battery will add a DC
level to the AC voltage.

     tom ..

 
 
 

Why don't my LTI AF Horns Work, Part 2

Post by john kel » Wed, 02 Aug 1995 04:00:00



: If you parallel a DC voltage source (battery) with an AC voltage
: source you will have problems. There will be a high current between
: the two sources. If you want to superimpose a DC voltage on an AC
: voltage - put the two sources in series. The battery will add a DC
: level to the AC voltage.

:      tom ..

I tried to say that earlier but there was a comment that it must be in
parallel.  I suppose the battery would have to get hot to make a
believer, but it looks like that wasn't enough |^).
Now I'm inclined to believe that the Lionel unit needs a fairly
substantial DC component....maybe several D cells IN SERIES might do
the trick, but it would be a lot easier to figure out if it were here
on the bench. -Bob

--
Dr. John R. (Bob) Kelty                 voice:     (402) 472-2793
UNL Physics and Astronomy               fax:       (402) 472-2879

Lincoln, NE  68588-0111         "not worth the bw it's sent over"

 
 
 

Why don't my LTI AF Horns Work, Part 2

Post by Christopher D. Colem » Sat, 05 Aug 1995 04:00:00



Quote:


>: If you parallel a DC voltage source (battery) with an AC voltage
>: source you will have problems. There will be a high current between
>: the two sources. If you want to superimpose a DC voltage on an AC
>: voltage - put the two sources in series. The battery will add a DC
>: level to the AC voltage.

>:      tom ..

>I tried to say that earlier but there was a comment that it must be in
>parallel.  I suppose the battery would have to get hot to make a
>believer, but it looks like that wasn't enough |^).
>Now I'm inclined to believe that the Lionel unit needs a fairly
>substantial DC component....maybe several D cells IN SERIES might do
>the trick, but it would be a lot easier to figure out if it were here
>on the bench. -Bob

>--
>Dr. John R. (Bob) Kelty                 voice:     (402) 472-2793

I mentioned parallel, and Tom is quite correct in what he says. To
place an AC source in parallel with a battery tries to force the
battery (which has a fixed voltage which is a factor of 1.5v) to
have the same voltage as the AC source. That is bad, as where hooking
them in parallel will force them to have the same current (which the
battery can vary).

But, as I said in an even earlier post, I used a DC power pack which
is in fact an AC transformer with a Rectifier, and is more voltage
forgiging.

Anyway the reason I recomended parallel (if your DC source allows it)
is because it is current that activates a coil, not voltage, activates
the whistle controller (at least on older units), and Parallel
superinposes the current. Series will still work because, since you have
a colsed circuit, a superinposed DC voltage will have a resulting DC
current (which does the whistle activation). Nevertheless Parallel
is preferable.

Now forgetting eveything I just wrote, yes use your batteries in
series with your AC transformer.
--
 ______________________________   Chris


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