# Problem? with Bachmann Automatic Reverse Loop Module



## RT_Coker

I have two reverse sections that use this module. The problem occurs when a 3 diesel consist is in either one of the reverse sections; there is a very noticeable slow down of the diesels. One of the reverse sections is setup exactly as described in the module’s manual (figure 4). I tested this section with a static load (two 1156 light bulbs in series) drawing 1.36 amps and measured 2.9 volt drop in the reverse section as compared to section providing the module input. I suspect that the problem is with the long wires supplied with the module. Unfortunately if I do not use long wires to connect the modules, they will compete (chatter) with the fault detection in the 5 Amp booster.

If you have had this problem and solved it (or otherwise have a useful suggestion), I would appreciate you help.
Thank You!
Bob


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## RT_Coker

In order to verify the voltage drop was not in the module, I removed the module and direct connected the reverse section using the supplied wires. >2.5 volts drop in this configuration. So I apparently have 5 amp auto reverse modules with (what I call) half- amp wires. [I will bite my tongue and not say what I would like to.]

So I am now in the process of splicing the connectors onto suitably sized cables, pulling up track...
Bob


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## DonR

Bachmann supplies very small gauge wires for the
controllers, reverse and main. A long run could have
a voltage drop with a 3 loco load.

However, recently, I ran 2 GPs pulling a very long freight, 
2 GE 70 ton switchers with about 6 cars, an F pulling 4
lighted passenger cars and an S4 heading another 
several cars. All this was drawing power through
those same small Bachmann wires from the main controller. It was a 
short run of wire however. It will be interesting to hear what
you discover when you increase the gauge on your
set up.

Don


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## RT_Coker

Don,
The two long wires supplied with the modules that I have total ~12 feet, thus these particular wires in this application are effectively half-amp wires on 5 amp modules. I agree the much shorter power wires that come with other units should be a lot less of a problem.

I spliced one set of wires so that there is ~12 feet of 18 gage speaker wire and ~5 inches of existing small gage wire with connectors. The first reverse section (which is connected according to figure 4) now has no noticeable 3-diesel-consist slowdown (<1 volt voltage drop). 

The second reverse section is the same except there is only ~2.5 inches of existing small gage wire. The track ends of these wires are soldered to curved track pieces. So far I have not been able to get this section working again, even after a lot of trouble shooting. Before I had put the existing long wires on this section, I had tried using the short power wires. The section work fine on short wires with one diesel but would not work with a 3-diesel-consist. 
Bob


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## DonR

Ain't right.  

If changing to heavier gauge wiring solved the issue
on Reverse controller A the same results should
come from controller B when so wired.

So what is the difference between the two circuits?

First test that occurs to me: switch controllers. If
you still get 'slow down' on your consist then it could
be a wiring or soldering problem. Something
is loading or adding resistance. Frustrating. 

There is one other thought. Are both controllers taking
power from a nearby track or a good buss? Is the input
voltage the same at both controller locations? Tricky
to measure since track power is not pure AC or DC.

If you get it solved let us know...others are sure to
run into the problem some time.

Don


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## RT_Coker

Don,
Great suggestions! Being an old electronics trouble shooter, I have already done most of these. I have about reached the point of confirming this is my ongoing problem (my 5 amp booster does not like to work with my auto-reversing units).

When I deviate from the recommended connection points and wires in the auto-reversing units, my 5 amp booster and auto-reversing units do not like to work together. The one exception to this (for now) is the reverse section with the 18 gage wire. If it starts having problems, I plan on moving the auto-reversing (isolated) section to a curved section of track and reinstall the half-amp wires (so the 3-diesel slow down will look more natural).

I wish I had not tried to change the second reverse section, it is just about all curve track, so the 3-diesel slow down is not a big deal there (looks kind of natural). I am getting tired of using my layout as a compatibility test bed, so I will do a lot of thinking before running a few more tests. If nothing pans out, I will just reinstall the half-amp wires in the second reverse section.

Bob


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## DonR

Bob

Me too. I've been tinkering around with electronics since high school but
never was stirred to get beyond the tube type arena. That pretty much
leaves me out when it comes to solid state circuitry. 

I have never tried a 3 loco consist on my reverse loop. Will give it
a shot today and see what happens. Different from your set up tho.
I don't have a booster, only the original power supply from
the Bachmann starter set.

I do notice that when there is a short on the isolated section the
Reverse Controller ticks madly. 

Don


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## RT_Coker

Don,
With just 1 amp of power, you may not be able to notice much of a slowdown in a 3-diesel-consist.
Do not remember having shorted a reverse section yet. But I do use a relatively inexpensive remote AC power switch on the booster, so that I can quickly kill power to the layout (saves a lot of ware on internal relays as well as quickly preventing a lot of train crashes).

I tested with my starter set controller system powering the layout. The only change was an added plug with short wire and terminal block connecting to the track booster power wires in place of the booster. The second reverse section works fine! Sure wish I would have tried this before I pulled track up (re-soldering & double checking the connections).

I am thinking that I will just add some of the half-amp wire to the existing good wire connections so that the second reversing unit will act like its compatible with my 5 amp booster. I will want the good wire connections if I decide to try a different type reversing unit in the future. 
Bob


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## DonR

Bob

Are you saying now that both reverse loops maintain your 3 loco consist at speed
when you are running on ONLY the original Bachmann power supply without
the booster in the circuit?

If so, wonder why your 5 amp booster affects the operation
of the reverse loop with the effect of slowing the locos. Are the
reverse loop controllers powered by the booster when it is in
the circuit?

I would be interested in what Bachmann says about this situation.
They have a user forum for that.

Don

Don


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## RT_Coker

Don,
I only used the “original Bachmann power supply without the booster” to verify that the second reversing section was working (1 diesel only). This confirmed (for me) that the second reversing section problem was the booster and reversing unit not working with each other. Both reversing units are powered form the track adjacent to their isolated section.

I attribute the difference in the reliability of the reversing section’s ability to work with the 5 amp booster to the difference in their (electrical) distance from the booster’s track connection. The first one was more time to function before the short-detection-protection circuits in the booster apparently start interfering. I only have one booster, so in all fairness to Bachmann, there could be something wrong with my booster.

The booster does not cause the slow down, it simply provides enough power (> 1 amp) to make the problem more noticeable (and annoying to me). The slowdown is (was) due to the voltage droop in 12 feet of (what I call) the half-amp cables. (These cables are so small it is hard for me to even estimate the gage of the wire.)

Based on my many sad experiences, I do not use (nor recommend) Bachmann’s forum or technical support to anyone.
Bob


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## DonR

Bob

NIMT and others have mentioned that the 'wave form' to the track
varies between DCC manufacturers. My electrical knowledge is
not sufficient to know whether that could be an incompatibility
between your Bachmann reverse loop controller and the booster.

On the other hand, I understand that any decoder will work with
any controller.

Or maybe it's what we don't know about how much we don't know. 

Don


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## RT_Coker

Don, 
I don’t believe the reversing unit uses the DCC signal. My understanding is that it detects an inappropriate current and then swaps the DCC phase to the reversing section.

My second reversing section seems to be occasionally failing to operate correctly. I have bought two used AR1 reversing units and will probably try one on this section. However, my web research leads me to believe that I actually need a unit with a fast solid state switch instead of a relay switch. 

I recently found out that if I have a loco across either reversing track gap when the booster is powered up, the reversing unit and the booster “chatter” with each other until I kill power. I have no idea whether this is typical or is just particular to my setup.
Bob


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## DonR

Bob

If your Bachmann auto reverse loop controller is not getting 
track voltage FROM THE BOOSTER...that would be a possible
clue to what is taking place. I can see why both units would
chatter. 

First, it's important to note that the isolated reverse loop
gets it's power from the reverse loop controller.

When a locos power pickup wheels first touch
the isolated section track the reverse loop
controller senses that the polarity in your isolated
reverse loop is opposite to the main. I an instant, it reverses
the isolated reverse loop polarity and the loco continues
unperturbed. 

If you are powering the reverse controller with some other
power source sparks could fly. That would be the
chattering you hear. 

I feed my reverse loop controller from the same bus that
feeds the main track. The output of the reverse controller
feeds the isolated track.

Take a good gander at the power feed for both reverse loop
controllers. Both should be getting power from the same
booster that is feeding the main tracks. The polarity is
not important in this instance since the reverse loop controller will sort it out.

I'm beginning to think that you have a line from the main
DCC controller feeding the reverse loop controllers. 
Don't do that. Not nice.  And you
are running your DCC controller feed then into the Booster
that powers all of your track except the reverse loops. 

Let us know what you find.

Don


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## RT_Coker

Don,

Both my reversing units are setup to get power from the track adjacent to one of double gaps of their isolated reversing section!!! And have always been that way throughout this _half-amp wire _problem! 

During my earlier experimentation, I used different types of connections and shorter wires. I cannot remember having any problems when using my EZ Command. However trying to use the 5 Amp booster with the reversing units has been a constant reoccurring headrace!

From previous post: “One of the reverse sections is setup exactly as described in the module’s manual (figure 4).” This first reverse section was all Bachmann products and setup exactly according to the Bachmann manual, except for one set of plastic rail joiners! It is now the same, except the _half-amp wires _are replaced with _18 gage speaker wires_ so that my 3-diesel consist does not execute a very noticeable slow down in the reversing section.

And 

From previous post: “The second reverse section is the same except there is only ~2.5 inches of existing small gage wire. The track ends of these wires are soldered to curved track pieces.” To my knowledge Bachmann does not make the curved track equivalent of “Bachmann HO Scale Train E-Z Track Nickel Silver/Gray 9" Power Terminal 44597”, thus the reason for this solder wires.

Buy the way; the booster setup is all Bachmann products and setup exactly according to the Bachmann manual, with the exception of two added terminal lugs.
Bob


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## DonR

Bob

You gotta be at wits end on this. 

Looks like you've covered just about all of the bases.

The only possibly useful thot in my noggin right now
is the sensitivity adjustment on the reverse controller.
If you haven't already jiggled it, some tweaking
could improve the 'chattering' situation. 

I'm still hoping someone else can join in this 
puzzler. Possibly some guy has run into the
booster vs reverse loop controller face off.

A question did pop up...do you really need the
booster? I regularly run 4 locos at the same time
on my EZ Command starter set with no
problems. Power supply just warm to the touch.

Don


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## RT_Coker

Don,
Thank for the help!

I have tried the sensitivity adjustment on the reverse controllers. My experience has been that this setting does not need tweaking when the overall setup is not causing problems. 

I like the booster and need its power (3-diesels pulling 44 weighted freight cars up a ~3% grade). I will also have a 4-diesel consist with sound that I will be using after I get things running more reliably. The booster also makes it convenient to plug/unplug different controllers. It is nice the use the EZ command for my grandkids, and when I need a simpler and more reliable controller for trouble shooting. I also plan on using a pulsed DC controller (with just one DC enabled engine on the layout district) as needed for testing and whatever.
Bob


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## waltr

Is the Booster setup to also "auto-reverse"?

If you are looking for solid state reverser then I suggest the Tam Valley From Juicers. They have a jumper to tie two outputs logically together (if one detects a short then both switch polarity) on their dual and hex units.


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## RT_Coker

Thanks!!!
My booster type doesn’t have auto-reverse. 
The Tam Valley Auto-Reverser looks great to me (realistic specifications & user’s manual). If the used AR1’s I have coming don’t work well with my booster, I will probably try them.
Bob


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## RT_Coker

According to my calculations the half-amp wires are most likely AWG 32 to 35. If I a correctly interpreting the wire AWG table, this size wires should become “blown-fuses” after ~10 seconds of 7 to 4 amps, and the recommended maximum current is 0.53 to 0.27 amps. It is hard for me to believe these wires could be safely used at 5 amps.

Put the used AR1 reversing unit in the second reversing section (without the half-amp wires). So far, no more reversing failures and no 3-diesel slow down. The end (I hope)!
Bob


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## DonR

:appl:

Lotta fudgeting around but you finally got there.\, Bob.

Hal lay loo ya!

Don


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