Lionel FT sound performance?

Yes, the diode strings will do this, I have done it.  If this is conventional controlled, I have also tried wiring the motors in series, with good results.   

I have also added a thermistor with the diode string.   This is a device whose resistance decreases as it heats up, giving very slow and gradual acceleration from zero.

An older thread on using series wiring and a thermistor on a GP30.

Thanks!

I might give series wiring a try first since it’s no-cost and easily reversible...

Well, series wiring didn’t give me the desired effect... it did really tame the jackrabbit starts, but the maximum speed was drastically reduced, too much for a locomotive that could be called on to pull passenger trains.

The root problem of the locomotive starting to move as soon as the sound turns on, and the sound shutting off as soon as the locomotive stops moving, was almost unaffected...

What I’m looking for is the sound to start at something like 10 percent throttle (on the transformer) and the locomotive to start moving at something like 25 percent throttle.

The diode strings in series with the motor should solve the problem.  That reduces the voltage to the motor and keeps full voltage on the sound board.

It's unfortunate that Lionel saw fit to remove the battery connection from the Conventional RS-Lite board, a battery would have totally solved your sound issue at low voltages.

Should I expect a lower top speed with the diodes? (I assume the answer is yes)

If you're talking about the transformer at max, yes, you won't get the same speed as without the diodes.  OTOH, if you wire the motors back in parallel, I can't imagine it won't have enough speed.  If you need more speed than that, I'm out of ideas.

The drop in top speed (yes-max transformer) was drastic going from parallel to series, acceptable for a freight-only engine but too slow for passenger in my opinion... I’ve already gone back to parallel wiring...

Full throttle is too fast in parallel, but not fast enough in series. If parallel with diodes is somewhere in between that would work nicely!

Just ordered a bunch of diodes (1N4005). I’ll update when they get here and I get them installed...

You'll want to order again, that's not what you need.  Look for something like the 1N5400 3A diode.  1A is too wimpy for the job.  Search for them on eBay and specify US shipping only.

I thought I read in another thread that you used the 4005’s... thanks for clearing that up... don’t want to release the magic smoke...

1N5400’s ordered...

The smoke would come from the diodes in this case, but no sense in doing that.

Well, I put 5 diode pairs in series with the motors and it made no difference. The motors still start (loco starts moving) as soon as the sound starts. I guess it’s not supposed to let the engine run when the train isn’t moving to save fuel and lower emissions...

That's odd, you should have gotten at least 3 volts of drop through the diodes.

This is how I wired them...

I only showed 2 pair of diodes in the drawing because I ran out of space on the paper, but I had 3 more in line...

Not sure why that didn't work.

Is it possible that my MTH Z1000 comes in at a high enough voltage that there’s enough to spin the motors as soon as the engine sees voltage?

Edit: checked the voltage with the engine on the track, my fluke 115 true rms meter shows the voltage starting at 4.5v

I will say that it seemed to move slower when it started with the diodes than without, so I think they were doing something...

The chopped waveform does have a higher peak voltage right from the start.  Even when you crack the throttle, it'll be a fairly high spike.

Z-1000 as minimum throttle.

Here's the Z-1000 at half throttle.

And at full throttle.

Well that looks... interesting... I guess it works, but it sure doesn’t look good to me...

@gunrunnerjohn, I'm curious as to what scope you used to get those images. I have a Tektronix 2335 on my bench and it shows the same thing, but it doesn't speak "computer" at all and taking a picture of a CRT is... uh... well... not quality.

I have one of the many digital scopes on the market, in my case an ATTEN ADS 1102CAL, a dual-trace 100mhz model.  It writes the screen shots to a FLASH stick.  There's a computer interface, but I've never tinkered with it.

The slow speed performance is definitely better with the diodes, and the top speed is still pretty fast... I wonder if the sound would behave better on a different transformer...

Even though it didn’t fix the original issue I still prefer the diodes over series wiring the motors. Both configurations have better low speed performance than stock, but the diodes don’t kill the top speed as bad...

I’m tempted to put a diode string in my Williams SD45 and put the motors back to parallel...

The diodes solve the low speed issue without compromising performance and pulling power throughout the throttle range.  In that regard, they're a superior solution.  I'm not sure why the sound card still misbehaves, I did the same mod to a conventional locomotive for a customer and it solved the sound start-up issue.

@gunrunnerjohn posted:

The diodes solve the low speed issue without compromising performance and pulling power throughout the throttle range.  In that regard, they're a superior solution.  I'm not sure why the sound card still misbehaves, I did the same mod to a conventional locomotive for a customer and it solved the sound start-up issue.

When I did this wiring years ago (mentioned above series motor wiring with thermistor), it was on a conventional locomotive, and it "solved the sound" problem as well, for that loco: the sound started before the loco began to move.  

I also worked this on Bachmann SD45s (a pair, second wired to run in reverse), using diodes and the thermistor.   Added a sound card from MRC in each loco.   Loved it, but am now running LC+ with Legacy, so have not run these for years.   These were VERY fast locos straight from Bachmann, so they still had a strong top speed after.

No idea why your sound is not starting before the loco moves. 

You could try an experiment with all 10 diodes in one direction, just to test if more voltage drop will get the sound to come on before the loco moves.  Nothing else to buy, just a concept test.

If I’m reading those graphs right it looks like the output of the Z1000 is more like PWM... in other words it appears that it pulses 18v, but varies the “on time” to control speed. If that’s true then the motor would still be getting spiked with around 14ish volts with the diodes in circuit, which is enough to make it go... I suspect that the engine would behave like I want it to on a different transformer, one that puts out a sine wave and varies voltage to control speed...

I’ve also got the idea in the back of my head to put a Lionchief board in it and run it on Bluetooth from my phone...

@Steaming Jon posted:

If I’m reading those graphs right it looks like the output of the Z1000 is more like PWM... in other words it appears that it pulses 18v, but varies the “on time” to control speed.

While I suppose you could draw some parallels to PWM, they're really just mangled sawtooth waveforms, the Z-1000 controller is a simple triac controller, no fancy PWM in sight.   Let's take a closer look.

As you can see, the first waveform starts earlier in the 60hz cycle and thus has a greater part of the sinewave.  The second waveform is a lower throttle setting, and it's just chopped off the left side of the waveform, the right side is exactly the same distorted shape as the trailing part of the left waveform.

PWM signals are typically controlled duration pulses.

Yeah, it’s definitely not PWM, I agree 100%.

It appears that the controller isn’t changing the voltage, but it’s shortening the duration of the wave, which is what made me think of PWM. Sort of similar, but definitely not the same thing...

My theory is that even though the diodes drop the voltage the motors are still getting a peak voltage of around 12-14v (I’m assuming there is some voltage drop through the reverse board also) which is enough to make the engine move right away...

@Steaming Jon posted:

It appears that the controller isn’t changing the voltage, but it’s shortening the duration of the wave, which is what made me think of PWM. Sort of similar, but definitely not the same thing...

That's exactly what triac control of AC voltage does, just chops off part of the waveform to vary the power.

Tried the engine at the club on a loop that was powered by an MTH Z4000 and I was able to get the sound to come on before it started moving... there wasn’t much throttle lever movement between sound and motion, but there was enough that a careful hand on the throttle could do the trick...

So here’s a question... I don’t have a good understanding of how ERR’s products work... as far as I can tell if I wanted to install sound and command from scratch I would need two separate systems/boards... is there a command board from them that I could install in this locomotive that would work with the factory sound system? I know their stuff is Lionel-based...

 I like the idea of command control, the club has command control, and I would like to pick up a command system for the home layout I’m planning because it allows for more prototypical operations...

@Steaming Jon posted:

So here’s a question... I don’t have a good understanding of how ERR’s products work... as far as I can tell if I wanted to install sound and command from scratch I would need two separate systems/boards... is there a command board from them that I could install in this locomotive that would work with the factory sound system? I know their stuff is Lionel-based...

Probably not as you need a sound board that is command capable, most of the conventional boards don't see the serial data.

@Steaming Jon posted:

 I like the idea of command control, the club has command control, and I would like to pick up a command system for the home layout I’m planning because it allows for more prototypical operations...

It would be nice to know what command system the club uses.

I haven’t paid that close of attention to the command system at the club, but I believe that the club has the legacy system based on some of the features I’ve seen other members demonstrate on their Lionel locomotives, and I think they have DCS for the MTH stuff...

I would likely use a Lionel system on my home layout (I wonder if used TMCC gear would be a budget friendly option) if I decided to go command control...

This is all hypothetical at this point, I haven’t even decided if I’m gonna do an around-the-walls layout or a table, so it’s all just brainstorming for now...

If you go with Lionel, do yourself a huge favor and get the Legacy command system!  It'll run all the TMCC stuff, but when you decide to upgrade to Legacy equipment, you'll already have the command system.

@Steaming Jon posted:

 I like the idea of command control, the club has command control, and I would like to pick up a command system for the home layout I’m planning because it allows for more prototypical operations...

The TMCC Cab-1L is a new version of the original TMCC Cab-1.

I use the original TMCC Cab-1 and Base and my newest locomotives are equipped with RailSounds 5, no legacy. This is definitely a cheaper way to go than Legacy. Furthermore the older RailSounds boards have CrewTalk that is specific to the locomotive:

Century Club 2 Empire State Express Dialog:

NYC 5429 You are clear outbound...

Legacy Empire State Express Dialog:

This is the dispatcher, take the green...

It's like they went back a step to RS4. Either way, it is definitely a cheaper way to go, great scale products for good prices. I've never spent four digits on a locomotive and I even have the C&O JLC H-7, all fully controllable with the cheaper system and I don't need to pay attention to a digital screen while I run my trains.