Train America Studios SAW V1.5 Interface to MTH Smoke Unit Interface

You will have to do more work to get the MTH smoke unit to work as you need a DC supply for the fan and you also have to replace the two resistors with a single one that's compatible with TMCC electronics.

I'd use the TAS Turbo board.

Question:  What type of locomotive are you putting this in? 

GRJ, 

This is going in an MTH Chesapeake & Ohio E-6 “A” unit that’s I picked up on eBay. The boards were gutted but it’s in mint condition. It has the motors, couplers, lights, smoke unit, etc. I have to figure out the lights but that’ll be easy. I have a K-Line regulator board from my parts bin but I have yet to test it to see what the output voltage is. 
BTW, I found the tach reader board for my TAS EOB. I installed it in my MTH cab forward a while ago and it runs great. I want to find articulated sound chips for the RS3 board. It currently has the J1 chip set in it. Any idea where to locate the chip set? 

Well, you'll have to replace the couplers as the MTH ones will fry the Lionel coupler triacs, too low of an impedance.

If the MTH locomotive was a PS/2 unit, all the lights are 6V bulbs except the markers, they're two red or green LED's in series.

As for RailSounds, I'd just shop on the Lionel site for a suitable articulated RS4 board.

Likely the crew talk won't match the cab number unless yours is #4276, but Lionel has a RS5 board in stock that will drop into the EOB motherboard.

Can I get away with adding a resistor to the coupler to increase resistance? Possibly measure a Lionel coupler’s impedance and build the MTH to match? If not, I have Lionel couplers. It’s good to know tho.

I wonder if they have a generic articulated board w/o a road number announcement? I’ll have to look into it. Thanks for all of the info.

I’m going to work on the E-6 some more tonight. I’m planning on switching out the marker lights to bicolor red/green LED’s. I’ll wire them up through the front & rear lighting circuits so they change color with direction. 

Thanks again for your help!

@DanVW posted:

Can I get away with adding a resistor to the coupler to increase resistance? Possibly measure a Lionel coupler’s impedance and build the MTH to match?

No, the result would be no cooking the triac, and no coupler operation.  The MTH couplers require more current to operate than the Lionel couplers as they're lower impedance.

Note that this is for MTH PS/2 couplers.  Sometimes with upgrades, I see PS/1 couplers on PS/2 upgrades, those also work for Lionel.

If the MTH coupler has a flat frame with a patent number on it, it's a PS/2 coupler.  If it doesn't have the patent number on the bottom, you can use it with TMCC.

@DanVW posted:

I wonder if they have a generic articulated board w/o a road number announcement? I’ll have to look into it. Thanks for all of the info.

I don't believe so, I ran across that issue several times.  Pretty much all of the RS4 and RS5 engine specific boards had the number in the crewtalk.

@DanVW posted:

I’m going to work on the E-6 some more tonight. I’m planning on switching out the marker lights to bicolor red/green LED’s. I’ll wire them up through the front & rear lighting circuits so they change color with direction.

Here's a wiring scheme for directional markers using the front/rear lighting outputs from the R2LC or R4LC.

A couple of notes.

• The number boards were incandescent, and since this engine didn't have smoke, I put them on the smoke output so they were switchable.  You can simply omit that circuit if you don't have number boards, or want to light them a different way.
• This design includes the .01uf load capacitors necessary to trigger the R2LC/R4LC triac if you using only LED's.  The ERR products already have the caps, so you can omit them.
• The LED's are all common anode, necessary for use with the TMCC lighting outputs as they're negative in respect to frame ground.
• The diode protects all the LED's from reverse polarity in the event the locomotive comes up in conventional mode.  Lighting outputs in conventional are full wave track power.

Click on the graphic to expand

John, whoever draws the wiring diagrams in Lionel's manuals needs to go to the Gunrunner school of drafting. They have the absolute worst diagrams where lines snake all over the page. They could make them so much easier to follow if say a speaker was next to the connections on the board rather than have the wires running down four sides of the diagram, same for program run switches and motors.  Whenever I have to use one I blow it up 200% and print it on 4 sheets of paper just to keep my eyeballs in their sockets.          j

Some of those are pretty bad, others are a bit easier to follow.  Most of those were done a long time ago, maybe an intern was pressed into service drawing them.

For simple stuff, like the lighting diagram, I try to put the components in a logical position so it's easier to follow how it all goes together.  It does make it easier to follow when I look at them later.

GRJ,

I finally had a chance to continue work on the install tonight. I swapped out the smoke unit (works as it should), swapped out the couplers (they were PS2 w/ patent info), and a few other things. Now I’m at the point where I’m installing the lighting. The marker lights (LEDs) are in series and are on a spring contact PCB that was fed by the original PS2 board. I’ll be changing those out to bi-color LEDs and wiring them per your schematic. The number boards, headlight, mars light, cab light, and front coupler (already moved onto TAS board) were all connected to a slave PCB which was controlled by the PS2 board. I’m trying to decide which is the best way to control the lights. Should I connect the mars light AND headlight to the front headlight output or run the headlight constant and just hook up the mars light to the output? I’m planning on running the number board lights and cab light on constant 6 volts. Any ideas or thoughts? Also, what is the best way to get the mars light working as it prototypically should? Are there any boards out there that can replicate the oscillating effect?

I use the Ngineering.com MARS Simulator for MARS lights.  They have a 3-LED version that is as realistic as you're going to get.  I typically use the single LED model, it does a very good job of looking like a real MARS light.  I'd run the headlight from the TMCC package as it will then be directional.  You can tap into that to run the MARS light whenever the headlight is on, or do something fancier.  Here's a way to turn the MARS light on only when the locomotive is in motion.  I sold kits for these a year or so ago, I have one kit left.

Here's a sample application that performs automatic cab light control, Rule-17 headlight dimming, and automatic smoke volume reduction when you're stopped.

GRJ,

Thanks for all of the advice. I think I’m going to order the Mars board as recommended to enhance the lighting. Where can I pick up the motion sensing board? You stated you have one left. Are you willing to part with it? Also, doesn’t your Super Chuff accomplish the same function? Can that be used instead? Or does that need to be wired to a reed switch or similar to detect motion?

Well, the Super-Chuffer is strictly for steam, unless you want your E6 to be chuffing.  It does also require a chuff input, but that's a moot point since this is a diesel.  Finally, it's more expensive.

I have one kit for that motion sensor left, if you are interested, drop me an email.  Note that it does require soldering surface mount components.  I also have a couple of them assembled, obviously not for the same price as I have to hand assemble them.

GRJ,

I need a little advice. I’m trying to decide how I want to hook up the smoke unit and directional lighting. The mars light will be connected to the motion sensing board so it illuminates in the forward direction.
The TAS SAW board I’m using has 12V AC directional lighting outputs. The smoke unit is Lionel/K-Line. Currently, (motion sensor not installed), the smoke unit doesn’t change intensity when at idle or while moving. According to the schematic you provided for the motion sensing board, the smoke unit’s resistor is shown, not the entire fan driven smoke unit. Is it just a generic smoke unit reference? Can I hook up the + lead for the smoke unit through the motion sensor to control the fan speed AND resistor temp? Will it reduce the voltage enough to slow the rpm’s of the DC fan motor and thus reduce the smoke output at idle?

Onto the next question; When wiring up directional 3V LED marker’s, should they be in series or parallel? If in series, should I incorporate the headlight LED into the circuit as well? I’ve already bridged capacitors across the R2LC pins as noted in another thread. I’m using bi-color LED’s for marker lights and 3mm warm white LED’s for number boards, headlight, Mars light, and cab light. I still haven’t decided if I should put a rear light and markers on this E-6 as they didn’t have them prototypically. Thoughts?
Thanks in advance for your help!

My diagram is indeed a "generic" smoke unit reference, hard to make one for every specific smoke unit.   The fan runs off a regulator, and even though you drop the voltage on the smoke unit, it won't change the fan speed. However, you still get the lower smoke at idle effect as it lowers the heat in the smoke resistor and you get less smoke.  You may have to "tune" the number of diodes to get the desired effect, sometimes I have too many and I don't get any visible smoke at idle.

I think some of the E6 units may have had a single reverse light, but I'm pretty sure I never saw markers on them.

If you're using bi-color LED's, how are you driving them?  Note that they have to be common anode if you're triggering on the forward/reverse light outputs.  Also, you need to add the .01uf caps across the lighting outputs, and if you have series diodes for the smoke, you need the .01uf cap across the smoke output of it'll stop altogether.

“My diagram is indeed a "generic" smoke unit reference, hard to make one for every specific smoke unit.   The fan runs off a regulator, and even though you drop the voltage on the smoke unit, it won't change the fan speed. However, you still get the lower smoke at idle effect as it lowers the heat in the smoke resistor and you get less smoke.  You may have to "tune" the number of diodes to get the desired effect, sometimes I have too many and I don't get any visible smoke at idle.”

That’s what I thought but I just wanted to make sure. I have a Turbo Smoke unit that has the decel feature but it’s bigger and space is getting tight.

“I think some of the E6 units may have had a single reverse light, but I'm pretty sure I never saw markers on them.“

I searched the internet, (for longer than I care to admit), for a pic or video of the rear of an E-6. Unfortunately, only a few capture the rear end. Not enough imagery to clearly see if there is indeed a rear light on the back of the A units. Maybe someone else can chime in?

“If you're using bi-color LED's, how are you driving them?  Note that they have to be common anode if you're triggering on the forward/reverse light outputs.  Also, you need to add the .01uf caps across the lighting outputs, and if you have series diodes for the smoke, you need the .01uf cap across the smoke output of it'll stop altogether.”

I was going to drive them off of the front and rear lighting outputs of the R2LC. I haven’t decided if I’m going to use resistors or the LEDCCLR. Obviously, I’d have to use 2 LEDCCLR’s then. One for each circuit of the R2LC which I think will be a waste. They are common anode LED’s. I already added the caps across the lighting outputs. Good to know about the cap for the smoke output. I’m planning of following your wiring diagram you provided previously for directional lighting.

Thanks again for you help!

You don't need a regulator for the lighting, just the resistors as I've illustrated.  In rare instances when the two LED's on one end are not perfectly matched, you need to have a resistor in each anode to balance them, I have had to do that a couple times.  Usually I have matched LED's from the same lot and one resistor suffices.

GRJ,

A few questions if you have a moment; You mentioned that I may have to “tune” the diodes for the smoke unit. Currently, it shuts off at idle. It returns to full output when the loco starts to move. I installed a cap across pins 5&6 to 3&4 on the R2LC as mentioned previously. Any ideas? 
Also, which R2LC lighting outputs get connected to the motion sensing board for front and rear headlights? I’m assuming the + side of the R2LC outputs but just wanted to make sure. The drawing illustrates the common anode to frame ground (+) and cathode to headlight(s) HOT lead. Any help will be greatly appreciated.

If you don't get enough smoke at idle, remove some diodes from the idle path.  There's actually a fairly narrow band from "burn the house down" smoke and "invisible smoke" from the smoke unit.