GOING INTO PRODUCTION...Controlling DZ-2500C switch machines at a panel with a momentary push button and a red and green LED

Hi Alan - neat project!

You might be interested in an Arduino-based approach that I developed which uses bicolor LEDs to indicate DZ-2500 position. Each board could control a dozen switches.

I decided to use a microcontroller because I also needed to monitor and control a DZ-1000, and wanted some complex behaviors for yard switches. For regular DZ-2500 control the discrete approach is probably simpler.

PC  - I saw what you accomplished with the Arduino, but I'm barely above diodes! LOL

This circuit will let me develop fairly complex acrylic control panels using acrylic  inlays cut with my GlowForge laser cutter. Before I had the cutter, it was very slow drilling holes in the Plexiglas panels I have made.

Now I laser cut perfect holes for the LEDs and switches as well as intricate  track paths.

The black lines are cut and the green areas are engraved. I cut two copies one in say white acrylic and one in say orange acrylic. I then inlay the orange track paths into the white background.

Alan,

Great project. I use Atlas switches and decided to go with an Arduino based system for a couple of reasons specific to the way the Atlas switches operate.

I really like your control panel. What program did you use to draw it?

I've been using CorelDraw for my control panel. After seeing yours, I'm going to have to work some more on mine. Here is a picture of what I have so far:

The circles are where I'm going to put my LED's and toggles. I definitely need to add some labels. I also may try to round off the sharp angles.

Has anyone looked into using ESP8266 for wifi connection to arduino? ESP8266 monitors and controls switch and reports through wifi to arduino status. No wiring to each switch or block detection needed. Commands go from Arduino to esp8266 switch controller. Have the esp8266 operate off of local track power. This could save lots of wire on a layout. Just wondering if I am re-inventing the wheel.

John  -   Mine was made using CorelDraw too. Nice feature is to draw lines for each run, then thicken the line and convert lines to objects; then I laser-cut the objects.

2500 circuit board is close; need to get board made and populated; each board can power 20 switches.

Alan, do you have a schematic of the circuit you used with the DZ-2500 lights?  I happen to be building using the DZ-2500, and I'll be dispensing with the DZ-2501 buttons as well.  I'm thinking it would be cool with just a single bi-polar LED for red/green, saves panel space and still gets the point across.  Given the fact that sometimes the "thru" path is not the normal straight path, it should also have a polarity reversal capability, maybe a simple jumper.

THANK YOU GR JOHN  I was hoping you ask to review the circuit; and yes don't see why it couldn't power a bi-color LED. 

Even though I believe my son and his friend are talented EEs they have no real idea about this application.

I have a few changes to make to it and then I will send it to you.

It should be a reasonably simple job, I just haven't really looked at the signal from the switch machine yet to see what I might encounter.  From looking at the DZ-2501 button PCB, I'm assuming they do something similar to Fastrack switches and flip the polarity of the indicator voltage for switch position. 

I'm at the point where I have all the switches setting in position on the layout and I'm jockeying them around to make everything work, but soon I'll be wiring and wanting to know how I'm going to deal with the panel.

GR John - If you like you can do an .svg file for the panel  I can laser cut it for you.I cut the track plan as an acrylic inlay. 

Otherwise email me a drawing and I can make an .svg file in CorelDraw  for you to review and then cut that; Panel size for the cutter is 20" x  11". But you can of course put multiple panels together.

I will certainly keep that in mind once I have a finalized plan and have the track down.  I don't think it's a question of creating the .SVG file, it's an issue of creating one that looks good.

My layout is only 23 x 12, and I'm not going crazy with track, so I won't need that big a panel.  It's looking like I'll have less than a dozen total switches, about half of them concentrated in one area.  

I'm figuring on putting a temp panel just to get things working with a large connector feeding it.  That way I can pre-wire up the final panel without doing any external wiring and just drop it in, presuming I wire it correctly.   I would think a 20 x 11 panel would be more than sufficient to present a graphical representation of my layout.

John

When the time comes; the "cast" acrylic, can be  between 1/8" to 1/4" thick. Sign shops have various colors, find contrasting ones like orange and blue. Any plastic supply co. usually can cut pieces to the size.

@gunrunnerjohn posted:

Alan, do you have a schematic of the circuit you used with the DZ-2500 lights?  I happen to be building using the DZ-2500, and I'll be dispensing with the DZ-2501 buttons as well.  I'm thinking it would be cool with just a single bi-polar LED for red/green, saves panel space and still gets the point across.  Given the fact that sometimes the "thru" path is not the normal straight path, it should also have a polarity reversal capability, maybe a simple jumper.

John, if you follow the link in my reply above, you'll see an installation I did with bicolor LEDs.

I get 1.1 V on the DZ-2500 white wire when straight and 5V when curved. That will read low and high on the Arduino (running at 5V of course) without any additional circuitry, and driving the white wire low toggles the switch.

Of course, with the Arduino approach, you can program as complex behavior for paths as you want. For example, I have a blinking indicator that alerts the operator that one or more of the yards is open, and the associated toggle will close off all the layout's yards.

Truthfully, I wasn't planning on going full blown automation, I'll be happy with just a nice panel and properly working lights for now.

If it's anything close to those values, it's a piece of cake to do a very simple circuit that will reliably light only one LED.  Adding a jumper would be easy.  I'm thinking along the lies of a Schmitt trigger 2-input XOR gate for each LED.  One input goes to a polarity jumper, the other to the white wire, the chip powered by a simple 5V supply.  Something like the SN74HCS86 would give me a four channel board.  I'd need an inverter to do the bi-polar LED.

I guess I need to put one of these on the bench and check what I get out.

Just measured, no sweat!  1.52 volts max at low, average 1.1, 5.66 max at high, average 5.2. 

I've always wondered just how the DZ-2500 uses the white wire as an input and output simultaneously... it's not apparent from the patent diagram, but that diagram may not represent the actual product.

I noticed a couple of dual use wires, a little bit of thought went into that one.  Contrast that with the DZ-1000, it's just a motor.

20  2500C s can be controlled on this board; 10 each per circuit.

Close up if the individual  circuit. 

Resistor values are show; Q1 and Q2  are Mosfet-NCH-AO3404A (2); Caps C1 and C2 are Rubycon 220uF; diode GS1GE; the connectors are J1 is the power  18vac; Connectors J2 and J3 go to the Red and Green LEDs on the panel; J4 goes to the momentary contact switch on the panel; finally J7 goes to the white wires of the specific DZ-2500Cs on the layout.

I plan to make about twenty of these.

at this point; I DON'T KNOW IF THIS WORKS SINCE I HAVE YET TO HAVE THE BOARD MADE AND POPULATED.

Alan

Help me understand the value of this idea. Why would I want this instead of a) having switch controls along the fascia of the layout close to the switches, or b) controlling the switches through DCS using an AIU?

The reason I ask is that to me, the idea of having a "control panel" seems to me to defeat the purpose of having walk-around control, however that may be implemented. You have to go to the control panel to flip the switch(es) and you have all these long wire runs from the switches to the panel. 

I'm sure I've just missed the advantages of the control panel approach. Can someone set me straight?

Don 

Don

If you have a dozen or so switches walk around is fine; however if you have THREE or FOUR-dozen switches a panel is needed.

Great Work on the panel controls. Did you consider a breadboard first, before PCB Production? Just asking, as PCB's aren't free.

While PCB's aren't free, they're pretty close.

Last December I posted this animated circuit: 

https://www.falstad.com/circui...4+40+0.1+3+2+25+3%0A

Clicking on the "H"  or "L" switches the LEDs from Red to Green that simulates a momentary contact switch on my layout control panel to control DZ-2500C switch machines on the layout. The corresponding Red and Green LEDs would be attached and wired to their proper positions on my layout control panel for each switch. 

I wanted the final circuit to have the capacity to control at least 20 DZ-2500C switch machines.

Seven months later (I'm slow) I have the Eagle designed "Panel Interface" circuit (PIC) and corresponding Gerber files to have the circuit made and populated. 

There are two circuits on the PIC that control up to 10 switches each. Each DZ-2500C circuit "SW 1-20" has one white wire port, one momentary contact switch port and two LED ports each for both RED and GREEN LEDs going to the panel. Each circuit is powered by an 18 VAC source.

So the hook up takes the white wire from the DZ-2500C switch machine on the layout to one of the SW circuits. The switch machine's red and black wires are powered separately not through the PIC.

Since a Chinese company is making the board I added  the copyright notice... like they are going to steal this!

I am making about 10 boards at first.

2)  Is there a distance limit between your board and the Red/Green position LEDs.  Between the board and the momentary contact switch?  I want the momentary contact switch (maybe the LEDs too) next to the switch it is controlling, which could be 40' of wire away from your board.  I will not have a central control panel.

3)  There is an issue when a DZ-2500 fails it takes out the other DZ-2500s in the same circuit.  The Lionel breakout board is suppose to help this.  Did you put in protection against this type of failure?

You probably answered all these earlier.  I kind of stopped following this when it went beyond my technical understanding.

All this circuit does is replace up to 20 DZ- 2502s with a momentary contact switch and two LEDs for each replacement that can be wired from the DZ-2500Cs to a layout control panel. It only uses the white wire. It doesn't touch the blue wire that can be wired with the Lionel breakout board.

As to wire distance, I am using the white wire as a trigger to determine the position of the DZ-2500C so any distance issues would be same as with the DZ-2502. I know of no distance issues as none are stated in the DZ-2500 manuals.

As to a cascade failure, each switch is isolated and controlled by a separate circuit that has its own momentary switch and LED control circuit.  The Lionel breakout board is used to control the switch via the blue wire that is not part of and outside of this  circuit. So I don't see an issue with that and it could still be used in tandem.

Thank you.

Reading the description of your circuit, it looks like I can have the momentary switch located on the edge of the benchwork, along with the red/green LEDs, near the switch it operates.  I will be able to use the Cab2 to set the switch from a central location, or use the momentary switch when I want to be close to the switch for switching operations.  No mater whether I use the Cab2 or the momentary switch, the LEDs will show the correct switch position.

Will it also show the correct switch position on an iPad using the LCS app?

It would be interesting to know if you can have the LEDs at two locations; next to the switch and on a dispatcher panel.

Your board really interests me as I get ready to wire my layout with about 50 RCS switches with the DZ-2500 (most are C). 

Ron

I am going from a large control panel to small distributed panels.

Originally I had thought of doubling the LEDs as the animation shows.

Once I have the board completed i will be able to try it with LCS and an iPad.

Ron

I'm making 10 boards. I don't need 10. For 60 RCS switches you'd need three boards that I'll send you.

Any reason you specified the AO3404A FET?  It appears they're obsolete.  I wouldn't think you'd need amps of capacity for this circuit, any reason you couldn't substitute a similar footprint part?  I don't see anything in the circuit that would preclude using other SOT-23 N-Chan FET parts.

Are you getting these assembled or are you building them yourself from blank PCB's?

I am  specifying SOT23-3 N-Chan FETs   5.8A/30V/35m0.

My error stated obove.

Assembled. I can't solder these parts. 

The mosfets: https://www.digikey.com/product-detail/en/on-semiconductor/NTR5103NT1G/NTR5103NT1GOSCT-ND/5801875

Correct, I was just wondering why the 5.8A rating, but obviously they work fine.  My point was those parts are listed as obsolete.

I'd like to do mine in the US, but I can't find anyone that isn't double or triple the prices for Chinese assembly!

Edit: I see the FET's you're using aren't the ones I saw the number for previously in the thread.

This whole quest started because I have way too many switches and not enough room for them on reasonably sized panels. Also, that the LEDs on the DZ-2502s are not singularly lit; which having a large number of switches is an issue identifying the layout switch  position. YEAH I could have ignored the lessor lit LED, but why should I have to??  I am beginning to love electronics and hate how poorly I did in those common core courses.

The panels I now have are shown below. All of the small DZ-2502 mounting holes and wire holes are hand(drill press)  drilled. Drilling all of the small holes without cracking the Plex was an issue. More importantly, lining up the CorelDraw  layout image with those holes was problematic at best.

SO I TRIED to fit the DZ-2502s on the panels but too many switches too little panel space. It's hard to see which DZ-2502 controls which switch. I NEEDED MORE ROOM while still having a reasonably sized panel!

To accomplish that goal I needed to build a panel like the one below and needed a way to interface the switch machines with momentary contacts and corresponding two LEDs; thus enter the Panel Interface Circuit (PIC). 

All of the holes in the new panel are perfect laser cuts for the momentary contact and the two LEDs. The holes are as small as can be to fit. Also, the routes are laser cut in one color acrylic then inlayed into a different color acrylic. No need for "bulky" DZ-2502s that are each replaced with one mom. contact switch and two small Red and Green LEDs.

Thusly, the  PIC was what I need to accomplish this nice and neatly.

Note that the LEFT side panel above and the lower panel are controlling DZ-1000 machines not DZ-2500C machines. I am slowly replacing all of the remaining DZ-1000s with DZ-2500Cs.

I expect the US price will be triple the Chinese price.

I should have a price quote shortly.

I shudder to think what I'd have to pay for my stuff in the US.  Years ago I used to have a decently priced source on the west coast, but they went under (probably priced too low), and since then I've been dealing with China.

I consider myself extremely lucky. I am 15 minutes driving time from All Electronics where I can get almost everything at rock bottom prices.

Nicely done. In the future to drill acrylic get a drill bit designed for plastics. They have a sharper point and won't crack the acrylic. Just google drill bits for acrylic. Don't use them for other than plastic though or you will ruin them.

Pete

Who needs a drill when you have a laser cutter that cuts ANY diameter. And NO drill bits to loose.

You said above that drilling it was an issue. A drill bit would be about 3 bucks. How much was the laser cutter?

Pete

Alan, I'll be wiring 23 switches in the near future. We'll have a combination of the Lionel 042 automatic switches and several Ross switches with the 2500 machines.

I  assume the Lionel switches use more current, will your boards be able to operate both types?

I also intend to use the momentary "lever" switch controllers that Lionel uses (I like their size and robust for the kids), but I've got the non-lighted ones and your solution is exactly what I was trying to figure out on my own. Will you sell these in the future? And any idea on price point? I'm thinking September I'll be ready for a board and start wiring.

And I know exactly what you mean about wishing you paid more attention in electronics classes. I'm a ME but find myself solving all sorts of problems electrically before trying mechanical solutions. Never too late to learn, though!