Occupancy detectors

[draskouasshat]

As i build my Cajon pass layout,  im getting the signal system planned out.
I am using my own relay logic and relays to actually drive the system and signal aspects per the prototype. The main thing i need will be occupancy detection. I've been experimenting with my own track relays but the tests are failing.
Do occupancy detectors have a relay drive coming off of them? Per the proto, id like have actual track relays and build off of that.

Adam Draskovich

[C855B]

Hi, Adam. I'm also working on occupancy detection. I don't recall at the moment... are you planning 100% DCC? That improves the selection and operability.

Basically, the closest analog to 1:1 occupancy detection is going to be current sensing with logic output. There are two ways to do this, diode drop, and current-sense coils. I am favoring the Bruce Chubb coil design, as modernized by Model Railroad Control Systems. What you do with relays from that output (pull-down up to 100mA) is up to you.

[draskouasshat]

Well darn, i was hoping to avoid old bruce. I don't like his cockiness towards knowing railroad signaling. He might know model railroad signalling,  but he's only at the tip of the iceberg with the real thing.
Ill look at his product though. Maybe I'll trade some real knowledge for some of his detectors? Lol

Adam Draskovich

[fcwilt]

I would suggest you consider using RR-CirKits Simple Serial Bus (SSB) products instead of the BDL168.

http://www.rr-cirkits.com/

The website is not much to talk about but the products are top notch and state of the art. The support is top notch as well.

The occupancy detection device from RR-CirKits (the WatchMan) makes use of detection coils that go over one of the power feeds to each block. The coils in turn connect to the WatchMan board using small gauge wire - I used pairs taken from CATx cable.

This allows you to totally separate the power wiring from the occupancy detection wiring.


There are SSB devices for every aspect of layout automation including turnout control, signal control, relay control, etc and they all derive from a basic board design and philosophy.

The SSB system is LocoNet compatible and works just fine with TC.

Highly recommended.


Frederick

[reinhardtjh]

Well darn, i was hoping to avoid old bruce.

Maybe it's a technicality, but it's not really Bruce Chubb.  It's just based on some ideas by Dr. Chubb. 

About us:

MRCS is your home for Open Source electronics for Model Railroad Operations. We offer Open Source hardware and software to help you operate your Railroad as prototypically as you like.

Our cpNode system is an updated, completely open, layout control system based on the popular and proven CMRI system (introduced by Dr. Bruce Chubb in 1984).

http://www.modelrailroadcontrolsystems.com/the-principals/

One of the main persons is Seth Neumann who is active in the NMRA Op Sig group and big into RFID.

[C855B]

I would suggest you consider using RR-CirKits Simple Serial Bus (SSB) products instead of the BDL168. ...

Much, much more than Adam is asking for, which is detection able to drive relay-based logic of his design. He is a signal maintainer for BNSF and is looking to emulate the logic and mechanics of what he works on every day.

[John]

Much, much more than Adam is asking for, which is detection able to drive relay-based logic of his design. He is a signal maintainer for BNSF and is looking to emulate the logic and mechanics of what he works on every day.

so back on topic .. the rr-circuits detectors normally run @ +0 to 5 volts .. you could probably hook a relay to that .. and when the output changes make your relay's do whatever they should be doing .. 

[draskouasshat]

Thank you Mike. I know it may sound word to everyone else, but yes,  i will be wiring my signal system per old Santa fe relay logic. I was even thinking today,  that i should make my pole line live, to send voltage for the home-distant relays, track relays,  and so on. Yes i love my job and i will be making this a fully functional signal system like it was for the most part. It sounds daunting, but with what i do for a living, it won't be bad. Not to mention, id rather troubleshoot my real signal system, instead of a bunch of chips hanging under the layout.

Adam Draskovich

[C855B]

You're welcome. It's a cool idea, really. "Old school", definitely, but there's an elegance to the simplicity. Me? I set aside the click-click stuff 35 years ago for computer geekdom and am going whole-hog with JMRI on my MRR. I'm willing to bet you're going to get there first.

[draskouasshat]

We will see. It might take a while to wire up operating pole line!
Trust me, the railroads going full electronic. I still like my clicking relays!

[peteski]

While my answer is generic, yes you can hook up output of an occupancy detector to a relay. Depending on the current and voltage capacity of the detector, you might be able to hook the relay up directly or you might need a transistor to amplify the detector's output.  Last few issues of N-Scale Magazine were addressing just this type of a question (including sample schematics).

Once you determine which occupancy detector works best for you (and it doesn't have a capability to directly drive a relay) we have members here who can help you out in adding a relay.

[C855B]

That's specifically why I suggested the MRCS detector. They must have a MOSFET on the output, which they rate at 100mA up to 60V. That is pretty generous and should cover a lot of relays.

[ChrisKLAS]

I've always subscribed to the theory that if it ain't broke, don't fix it. I have eight BDL168s providing occupancy detection on my 20 scale mile single-track main w/ passing sidings and I've never experienced a single instance where block was incorrectly reported as occupied or unoccupied. In fact, over 3 years running with BDL168s and SE8Cs, I can't think of a single time a block displayed inaccurate occupancy, a signal head showed the wrong aspect, or a switch was out of correspondence.

[Santa Fe Guy]

Whilst not as many BDL168's and SE8C's as you Chris (only 4 of each) we had very few issues using a similar system on my Santa Fe Railway Southern Division combined with JMRI . And we added relay clicking into Panel Pro so not only did it look like a real panel with switches and buttons it sounded like the real thing also with thanks to one of my close young friends. Signals were custom made also. Sadly the layout has been pulled down due to my wife and I downsizing however it lives on in a new location, bigger and better than ever.
Rod.