Seeking Advice on using a DPDT toggle switch inplace of the Lionel 5904-1 Sound Switch

How do you figure a switch is going to replace the diodes that generate the DC offset for the whistle & bell function?

Here's what goes into a whistle/bell controller.

@BAMBAMMorris posted:

I'm no electrical expert and I'm asking for educational instruction on how to wire this up so as to prevent damaging anything.  Since finding the Lionel 5904-1 whistle/Bell switch is tough, I want to use the DPDT toggle switch seen in the photo as a replacement.  I need to know how to wire this in between one of Harry Hennings upgraded ZW transformers, a terminal block, and the 3-rail track.  If anyone knows of any 5904-1 switches please let me know, Just private message me the source .  I've checked every source I can think of and no joy.

Call me crazy, but unless you added some circuit protection, I would not put anything, let alone a cheap 5904-1 switch between a ZW- upgraded or not, and my track. The first time a train derails, a minor short- becomes a MAJOR short and total and utter destruction of the switch and wiring.

I'm not saying you cannot put a switch, I'm saying big picture, don't put a device that was made for a starter set between a postwar 275W power supply, and some track that likely will see at least one short eventually.

Even worse, if you do use such a switch, then you can no longer use anything that depends on common rail for accessories or insulated rail sections.

If you really want bell and whistle, do it right either with a DIY diode box for bell and whistle or something like one of the better rated K-line heavy duty units.

And even then, you need some sort of fuse or circuit breaker on the output channels of that ZW.

gunrunnerjohn, I guess that idea just got flushed.  LOL  What is the best device to use for the whistle & bell function?  Does someone already make those units and have any units for sale anywhere?  I need three minimum.

https://ogrforum.com/...3#163884069800730333

I took Harry and Gunrunners advice a couple of years ago and placed the fast acting breakers between every power supply I have and the track for protection.

Myself and my friend Scott also from Alabama have been discussing this same subject for several months and we have been stumped and the information you all have provided has been very interesting and insightful.  It is greatly appreciated.

@BAMBAMMorris posted:

gunrunnerjohn, I guess that idea just got flushed.  LOL  What is the best device to use for the whistle & bell function?  Does someone already make those units and have any units for sale anywhere?  I need three minimum.

I don't know anyone makes something that I'd be willing to use, but you can look around.  I'd want more robust wiring and higher rated components if I were putting this in between the transformer and track.  Probably at least #18 wire and 6 amp diodes, and switches rated at 6 amps or more.  The boxes Lionel made were pathetic IMO, the wiring was positively anemic, and the diodes undersized.

https://ogrforum.com/...8#163884069800890718

Gunrunnerjohn, thanks.  I'm going to be looking for these components and see if I can possibly build one while learning.  LOL  Hopefully I don't light myself  up like Rudolph.  Granted the grandkids would be laughing.

B.B.,

Check out these two options.

1.) Not as smooth as a 5904 but it does get the job done, and it's fairly inexpensive:

   Lionel No. 147, 'D' Cell Horn/Bell Controller (5/29/22) | Melllow Hudson Mike

2.) Much more expensive when it was introduced because it had other features (power conditioning) this was manufactured by QSI, and was called the ACS-730 PowerGuard:

See this link as a start:

    Scan of the 4 page manual for PowerGuard (3/4/19) | DG

In addition to clamping voltage spikes this unit features both activation buttons, the whistle/horn button and the bell button.

You can find both of these options on the bay from time to time, or as others have pointed out, or will soon point out, you can also make your own.

Mike

Here's one I made years ago.  Since it was for a single train on the bench, I used 3A diodes.

For connecting to a layout, I'd use 6A diodes.  Also, I used a total of 5 diodes in each string.  Some have mentioned they needed an extra diode for 100% operation under all conditions, so I'd follow the schematic I posted previously.

For the inevitable folks that point out 6A is less than the transformer would likely put on the track, I point out that each diode is only seeing a half cycle of the power, so the diode pair is really rated at 12 amps.

@BAMBAMMorris posted:

...device to use for the whistle & bell function?  Does someone already make those units and have any units for sale anywhere?

The 5906 is a better choice for what you want to do.  You can brew your own and substitute heavier diodes and fast-acting switches using the info posted above.

Going back to @BAMBAMMorris possible original desire, a single DPDT switch can be used with any of the sound activation units to achieve both the bell and whistle. Here is a design using just 7 diodes. Breaker is optional.

I made Susan Deats' Sound Activation box substitute for the flimsy Lionel 5906.  It works really well and includes a block protection circuit, but you would need to modify it for both a bell AND a whistle or use two like Rob showed you above.

https://slsprr.net/features/SoundBlkProtect.htm

John

Everyone thank you for the great tips and diagrams.  It is greatly appreciated!