Williams Reverse Unit Question

Gordon,

I've got a scale Hundson, 746 J, and a couple of F3's.

I installed a fan driven smoke unit in the scale Hudson and the 746 J and noticed during the installation that the circuit board had a couple of plug receptacles with nothing plugged in and I was wondering if one of them is for an over ride switch that I could wire into it.

Paul

The extra plug ins are for hooking up an additional set of motors.

You won't be able to do a reversing thing that way.

Go to the Bachmann website under Williams and there hould be some info on how to convert a circuit board to the locking position.

Another way to get around the circuit board feature is to remove the circuit board from the motors and use a 6 amp 50 volt bridge rectifier to the motors.

A word of caution: never run the motors from straight track voltage!

Lee Fritz

Thanks guys, I found the info on the Bachmann website unfortunately it looks like more than I am capable of so I guess I will have to find another way.

Paul

Serows1, it really is not that difficult! take your time, use good solder and paste, and a small soldering iron! It has been some time since I did this re-fit, and I used the same plans that Gorden posted here! Same ones I was going to share, for the price of of switch and some of your time you will have just what you are after!

I'm with Uncle Al, not too hard. A half hours practice, and most "get it".

Garbage cans, and Dollar stores carry small electronic items (key chains/toys/etc) for a cheap source of something to practice on.

With diagram, and parts in hand, this could be taken to about any electronics repair shop if you don't have a train store near you. Or try an electronics class at a school nearby. 

I'm a little late to the discussion, but am interested in doing this myself, and was just looking at the instructions on the Williams site.  If you don't need a switch, and only want the train to run forward at all times, couldn't you simply figure out which two of the three terminals could be bridged, and forget the switch?

Keith

A few bucks for a bridge rectifier is the best way to do a fwd only dc loco in my opinion.

I'd also prefer to not jump/bridge, but remove, unwanted circuits.

Power application to the tail end of a circuit, even that equal to its normal output, doesn't seem the best way without knowing the in-depth characteristics of the board, and its components. Should you lose normal input, relationships change.

 E.g. You could begin creating broadcast noise unknowingly, create a magnet, burn out, or even begin a reprogram cycle, in a chip. Not real likely here, but not too far fetched. I've had all happen just testing circuits while power was off.

The OP's shying away from the switch idea after swaps, and such, led me to think that the board is based on newer mini-components too.

  Those tiny traces, and solder points are a bit intimidating to me, and I'm no soldering rookie. Soldering fed me for a few years.

Or maybe he just doesn't want to solder at all.

 A jumper would still involve wire and heat.

I don't think your getting any gator clips in there.

No. No gator clips <smile>.  I mostly like your idea of eliminating, and using a bridge rectifier.  Just not sure I want to eliminate other features (horn, bell, lights).  Haven't even opened her up yet, but I'm sure the circuit board is fragile.  Yet I may take a chance and give it a try.  I'd like to be able to run my Budd cars with a block control, but can't have them starting out in reverse every time the power comes back on.

Here's a question for you since you're more familiar with soldering than I.  Is there anything besides heat coming from the end of an iron?  I guess what I'm asking is if the soldering iron introduces any current of its own in to the circuit.

Thanks,

Keith

A soldering, if not malfunctioning, shouldn't introduce current into a non-powered circuit.

Hi Kpete,

You may not have to make any changes to the board as recent Williams locos will recycle to forward if power is off for more than 7 seconds. Check the instructions that came with your loco. Or, just cut the power for 10 seconds and see in which direction the loco starts.

Allan

Thanks John.  And Allen, seven seconds is kind of on the edge of what I need, but this is quicker than what I would have thought, and may make everything OK.  Thanks.

Keith

Or you can just buy on from Trainworld with a lock out switch already installed:

Reverse Unit W/Lockout

Not sure if you can hook up the sound boards to it but most Williams are designed like that.

jerry

YIKES Jerry!   For $60 you can have the ERR AC or DC commander, it offers a lockout capability, and you get command operation for free!

 I've not had that thought in twenty or thirty years I just accepted that it worked, and moved on.

 Unplugging or taking power off something? Commonsense-ish safety habit.

I would repeatedly short the high voltage lead on an old monitor every time I came back after leaving the room for long too. (too many idiots in the world to chance one played with the plug)

 I broke enough pen irons to know what the internals look like inside. A coil around a metal shaft is what I remember. Only touching only one end of the rod there should be no current flow to speak of.

  I never looked at what was in a gun. I have never broken or burned one out. Or even read the label further than watts. It's functioning, and still not transferring current to grounds is a mystery to me. I imagined it to be resistance of current going though the element, and building in the mass of the tip to hold heat, so we can release it on contact.

  It's element may be a layer of non-conducting metal, or a layer of a ceramic compound (?) under the top metal layer, separating it from the copper(?)element core. Similar to the burners of older electric stoves. (Any idea what those stove's heat elements coated/layered with?) 

Keith,

You can not bridge the terminals that are unused as they are for an extra set of motors or the Mars light.

You must do some re-wiring or soldering to the circuit board and add the switch in to it.

On older Williams F-7's I took out the circuit board for direction control and installed a bridge rectifier(the bridge rectifier converts the AC into usable DC) in it's place. One other note about adding a bridge rectifier and that is you will gain some power or voltage to the motors, and they will run a little faster.

Lee Fritz

The soldering gun is an interesting example of something that can affect a circuit if you have a tip issue.  It's really a big transformer with a single turn secondary.  Very low voltage, very high current.  If the tip breaks, which is fairly common with use, and you happen to touch both broken pieces to the circuit, you could toast something.