gunrunnerjohn posted:

I have to think this is killing gnats with a sledgehammer.  Am I missing something?  Why not just remove the 120V power from the layout with a trip, why all the high current relays?  One big control relay on the input power and then any sensing you desire for the power districts.

I too may be missing something but isn't that a Catch-22 situation?  That is, if you remove 120V AC to all 4 bricks then obviously all 4 brick outputs immediately drop to 0V (including the brick that is already at 0V from its derailment trip).  Now there is no indication of which brick tripped in the first place.  I think it's kind of neat how there are 4 "micro pilot lights" that run to the top of the board that directly indicate the status of each brick/block.

OTOH, I suppose one could say it's obvious by looking at the layout to see which block caused the problem, feel each brick's reset button to see if popped out, etc..  

Then, after MOW clears the derailment and resets any brick breakers, how do you "restart" the safety circuit?  That is, all brick outputs are now 0V so the sensing devices are continuously trying to remove 120V AC.  I suppose it could be as simple as a momentary bypass switch...but, as they say, the devil's in the details.

PLCProf posted:
...

I'm guessing that the DC supplies were intended to permit the use of 12 VDC sense relays, but the filter caps in the supplies caused the sense relays to hold in for a while after the power was lost, so the 8.x volt setting was chosen to put the relays right on the edge of dropout to speed up the response to a power loss.

...

Just talking........

Agreed.  We are just talking.  

ly relay spec

So if these are indeed the LY series relays, note that for the 12V DC version it Must Operate at 9.6V and Must Release at 1.2V.  I think that would be walking quite the fine line (i.e., delicate balancing act) to trim the DC voltage to 8.7V, or 8.8V, or 8.9V, whatever to drive a 12V DC coil that will hold until the capacitor drops to what could be as low as 1.2V!

Practically speaking, other than ASAP, how quickly must a safety system respond to one brick tripping?  Given momentum, if you instantly remove power the consist might nevertheless coast several car lengths...and of course the prototypes much further without dynamic braking.  So for a model train setup, I'd think maybe 1 second is a reasonable goal?  That is, consider a human operator visually watching.  A derailment is detected.  Now, in a panic, find the E-stop button on the remote fob which was supposed to be hanging on your neck but in all likelihood left somewhere because you had meant to change the battery! .  

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stan2004 posted:
gunrunnerjohn posted:

I have to think this is killing gnats with a sledgehammer.  Am I missing something?  Why not just remove the 120V power from the layout with a trip, why all the high current relays?  One big control relay on the input power and then any sensing you desire for the power districts.

I too may be missing something but isn't that a Catch-22 situation?  That is, if you remove 120V AC to all 4 bricks then obviously all 4 brick outputs immediately drop to 0V (including the brick that is already at 0V from its derailment trip).  Now there is no indication of which brick tripped in the first place.  I think it's kind of neat how there are 4 "micro pilot lights" that run to the top of the board that directly indicate the status of each brick/block.

I don't see this as a problem.  Your detection circuit could be independently powered and maintain the status of the trip, but the main layout would all be killed with a single power control.  I'm just at a loss why I need a ton of high current relays and the associated wiring and complexity if I want to shut the whole thing down anyway on a sensing circuit failure alert.

What I wanted to show is how the sense relays and relay logic* could be used for an interlock chain.   In logic terms it is and AND gate. Outputs are enabled if Brick 1 is on AND Brick 2 is on AND Brick 3 is on AND Brick 4 is on.

Since the control relays interrupt the power to the track, the bricks are still powered.  If you have a pilot light on the output of each brick you will see which ones that are on.

The sense relays could be replaced with simple sense circuits on each brick.  Optocouplers would allow the logic be done using low voltage DC that drives a single relay which in turn drives the power relays or with suitable output drive could control the power relays directly.  There are endless approaches here.

Controlling the 120V power only requires one control relay and it operates at lower current.  You do need to deal with 120V though.  There are prepackaged relays from controlling appliances so you don't have to deal with 120V - but I don't know if the right specs would be available.  Driving four fully loaded 180W bricks would be 720W.  That is 6 Amps on the AC side.  If you don't expect to use that much on average you could use a 5 Amp relay but you'd need a circuit breaker to protect the relay contacts.

With the 120V approach the system will latch in the off state when it shuts down.  Also it will power up in the off state so you do need a Start switch after power up or to reset.  If you have a power failure the system will be off when power returns until you press the Start switch - this is an added safety feature.

If you start using normally closed contacts you can avoid relays being constantly energized.  However you will lose the fail safe aspect of the relay power supply failing.  But if you stipulate the relay power supply will be on you can take the NC approach.

*Relay logic - I have an EM (electro-mechanical) Space Odyssey pinball machine from 1976.  EM pinball machines are all relays, switches and solenoids.  These machines have a score motor, essentially a washing machine timer switch on steroids, that turns until certain conditions are met.   The score motor is what makes the score roll up multiple steps on one switch closure.  Mine has a common problem where the score motor does not stop running.  Debugging this is no easy task.  The schematic is a ladder diagram (one way of showing relay logic) - it is 4 feet wide.

wmsmotor1

Cam

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Tried to take photos of relays, but no luck. to much glare, tiny printing on clear background, I have extra relays so i took those out side still no luck with photos. Soon you have to trust my poor eye site, and and no short term memory to wright things down correctly. There is two different brands of relays, Taking a long time to type this, ill wright it down and take photo.

IMG_7957IMG_7958

     Well this message took over 45 minutes and still not sure of what I wrote and got the photo standing on end.   Sure wish you guys would just stop by and look at it.  There is some wiring diagrams on it also, good luck in copying that down.                                                                                            

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The circuit of for this type of relay is simple.  Looking at the base with the the two vertical terminals at the bottom: the vertical terminals are the coil.  The horizontal terminals are the contacts.  You can see how these directly exit the base of the relay.  The top terminals are Normally closed, the middle terminals are the normally open. then the movable contacts.  One pole is on each side.

This is an Omron part.  I have attached a datasheet.  The part number should be something like LY2N-xx where xx is the voltage.

I can find the LY2N-J part numbers on the web but haven't determined this significance of the suffix.

(Forgive all earlier versions of this post - not having a good day.)

 

 

Cam

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penn station posted:

Since the control relays interrupt the power to the track, the bricks are still powered.  If you have a pilot light on the output of each brick you will see which ones that are on.

Depends on the brick, the Lionel PowerHouse 180 light doesn't go off when the breaker trips, for instance.  In any case, simply having the control logic remember the trip condition solves that problem.

penn station posted:

*Relay logic - I have an EM (electro-mechanical) Space Odyssey pinball machine from 1976.  EM pinball machines are all relays, switches and solenoids.  These machines have a score motor, essentially a washing machine timer switch on steroids, that turns until certain conditions are met.   The score motor is what makes the score roll up multiple steps on one switch closure.  Mine has a common problem where the score motor does not stop running.  Debugging this is no easy task.  The schematic is a ladder diagram (one way of showing relay logic) - it is 4 feet wide.

FWIW, I used to own a bunch of pinball machines and in high school I worked at a pinball and jukebox supplier fixing the machines.  I had to fix all the pinball machines I had later in life, that's how you get them cheap!  I had some of the relay models and a few of the electronic models.  There are tons of Internet sites dedicated to pinball repair, and you can get a bunch of expert help if you look around.  The fact that you have a a schematic of the logic is a huge plus, that should make it tons easier to track down your issue.

clem k posted:

….There is two different brands of relays, Taking a long time to type this, ill wright it down and take photo.

clem 12V DC

Clem, the 2nd photo is exactly what I was looking for.  Note that the relay coil white wrapping (inside the plastic case) says 12VDC (upside down in photo).  

But when you say two different relays, I wondering if some of the coils are printed with something other than "12VDC" or just two different brands of the same 12V DC relay.   I appreciate the time you've spent scurrying around gathering photos and such!  

Again, getting back to the matter at hand.  You have a system that works and have been kind enough to share what you have in response to the OP.  Practically speaking, I think it's unlikely that the OP will be able to exactly duplicate your configuration. 

At some point "we" need to agree upon exactly what this gadget has to do and come up with a complete parts lists and wiring diagram.  Many different ways to solve the problem.  It's just that all ideas eventually degenerate into actual work, and Nothing is so easy as the job you imagine someone else doing.

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Well, Clem apparently has a buddy who built it off-site and it just showed up plug and play.  Doesn't get easier than that.  

As I see, there are 2 things going on here. 

Thing 1 is a general discussion about what features might be useful in a safety relay system and how one might go about implementing it...using Clem K's system as the proverbial dart board.

Thing 2 is the specific task of building a system for the OP where at this point there are still some TBD requirements and logistical unknowns.  Who exactly is building this?  Is soldering and working at the component level OK?  Budget?  And so on.

Stan........ he will need someone to build this.... or get all the correct parts and an excellent diagram. I could work with him on this so very clear simple directions are needed and the correct components.   Like I told him I could take mine off layout and copy it, but I would not bet it would work, or the original (mine) would work again. 

Stan same relays two different brands? Hard to read printing. Here is what I think s on the other one.

CLION

HHC68A-2Z

JDX-13F     LY2

THEN SOME WIRING DIAGRAMS I CANT MAKE OUT

10A 240VAC/28VDC

MORE STUFF I CANT MAKE OUT, I THINK BRAND NAMES ?

IMG_7959IMG_7960

Ps lighting seems better, I can read easier now.

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safety relays for a couple bucks

If we're at the point of Thing 2 - actual implementation - then it's a matter of who exactly is going to do the work. 

Again, there have been several proposed alternatives in the Thing 1 category.  The actual material cost is quite modest.  The relays WITH socket are a couple bucks each (no soldering required).  Toggle switches with screw-terminals (no soldering required) are about $1.  Screw-terminal barrier strips (no soldering requried) are also modestly priced.  DC voltage regulator module with digital LED voltmeter are about $2 (no soldering required).

So taking a somewhat cynical view of the matter at hand, the material cost for all the proposed variations/alternatives will be small compared to "labor" even at minimum-wage whatever that is these days!

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For the track power stuff, at least #14 I would expect, that's good for 10 amps.  For short runs between relays and the like, you can get away with a bit smaller wire.

One thing interesting that Dale M mentioned back awhile is that the wire tables for wire gauge are designed for 120 vac and 240 vac. The issue is that there is an allowable voltage drop as a percentage of the line voltage. When the line voltage is only 18 vac then that voltage drop which was ok for 120 vac is too much for an 18 vac circuit.

Chuck TCA LCCA ARRL BMWMOA

I always compute actual wire drop when I'm working on wiring for train layouts.  For short runs, it's a bit less critical as the current carrying ability of the smaller wire normally isn't in question, but it's the voltage drop at the max current it'll see.

I searched for a packaged power control relay.  I found this controlled power strip.  The control input operates from 3-48VDC or 12-120VAC.   It has 2 normally open outlets, 1 nomally closed, and 1 always on.  It controls up to 12 Amps.  This avoid the need to work with high voltage wiring.

This could be used to control the power to the bricks.  The brick outputs could be monitored with optocouplers and a few other components, plus a reset switch.  The input resistance of the control terminals is not specified.  Based on examples it does not require much input current.

The price is $27 at site is https://dlidirect.com/products/iot-power-relay.  Could be useful for other applications.  It can be used with an Arduino for example.

At Digital Loggers

Cam

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Reminds me of those power outlets that turn ON at dusk and OFF at dawn.  About $10 at Home Depot:

dusk to dawn power output

The Thing 1 idea is to make a simple circuit that monitors the 4 brick outputs and turns ON a "fault" bulb or LED if one or more bricks trips its breaker.  This "fault" lamp would be placed against the outlet light sensor.  Ta da!  When the bricks are all working, the fault light is OFF and the outlet thinks it's night-time and turns on.  If any brick trips the fault light is ON and the outlet thinks it's day-time and turns off.   This widget only has 2 AC outlets so a 4-outlet power strip could be used to power 4 bricks.  Other similar light sensing strips have more outlets but I figure the existing bricks are probably already connected to a multi-outlet power strip.

 

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Yes.  The proposed method of cutting wall-outlet 120V AC voltage to all 4 bricks is another alternative.  These controllable power outlets usually have a relay inside but as pointed out, you don't have to mess with high-voltage wiring.

But again these controlled outlets are a Thing 1 discussion item...not a Thing 2 solution.

Anyway, along the lines of Thing 1 discussion, it may not be common knowledge that many of the DC-to-DC converter modules have a reverse-protection diode on the input.  Here is a close-up of what I believe is the DC-to-DC module that Clem has:

reverse protection diode

What this means is you can apply 18V AC brick voltage to these modules.  And for low power applications, then the half-wave rectification and modestly sized input capacitor (100 uF shown here) might just do the trick!  It might even turn out that ~9V DC (average) was all this module could put out when driving multiple 12V DC relays!  I was wondering where the diodes and/or bridge rectifiers for AC-to-DC conversion were in Clem's various photos and this is what I came up with.  Again, this is Thing 1 "just talking..." 

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