Robert Paisley's circuits

[cwobosn]

I have been searching the internet looking for block detection and signaling circuits that can be made and not purchased. I have seen a lot of references concerning Robert paisley's circuits but every time the page is not found. My layout is not a big layout and is DCC. I do not have a electronics background but like to "tinker". I would like to know if anyone has the diagrams that are referenced often as I would like to attempt this. If there are instructions on installing the system out there I'd like to look at them also. Thanks, Mike

[rrinker]

 Rob's web site was hosted at his ISP, they apparantly have stopped offering that benefit to their custoemrs and he is in the process of finding a new place to host his site. Since previously it was free and now he's going to have to pay a host - it may be a while.

The main component used in his block detector has long been unavailable. I tried building one a few years ago with what was listed as a similar substitute and could never get it working - further checking revealed the transformer specs were nowhere near what the original was (finding the info on it was was nearly impossible, even then it was discontinued and searching the part number revealed nothing but the surplus sale site wher eyou could buy them, no data sheets). My circuit possibly could have been made to work with a change of other components, but I moved on to other things.

 A good alternative is Bruce Chubb's DCC-OD. it uses the same principal as Rob's detector but adds an sensitivity adjustment. The circuit diagram is freely published if you want to tinker and build your own. There are also other detectors of this type shown here: http://dcc-mueller.de/wire4dcc/sensor_e.htm

Also, Iowa Scaled Engineering has released the schematic for their product as another circuit you can try.

 As for signal circuits, there are milliosn of them. The lastest trend in tinkering with your own is to use Arduinos, the hookup part is rather simple, and all the 'tinkering' is done in code - you conenct the block detectors and other sensors like turnout position (contacts off the switch machine are usually good enough) and then combine the inputs to determine which LED to light on the signal. SOmethign like "if block1 = empty and turnout3 = normal, set signal2 = green"

Combining it all, there are also multiple methods. I'm using a slightly modified version of Bruce Chubb's CMRI with Arduinos for the nodes, similar to what Seth Neumann is doing: http://www.modelrailroadcontrolsystems.com/cpnode/

                                  --Randy

 

[RR_Mel]

I’ve tried every kind of current sensor out there for over 40 years and really never found one that worked the way I wanted.  I ended up using IR LEDs in break beam mode.  They are a royal pain to setup because of curved track.  I have 31 beams for a little under 100’ of HO mainline, two beams over 12’ long.

 

The advantage of optical beams for me is it detects anything on the track at coupler height.  I don’t have to use loading resistors in my rolling stock to trip my signals and operate my turnouts.

 

I use across the track optical (IR) detection for turnout control (in my old age I tend to forget so my IR detection prevents a train from hitting an open turnout) as well as for my crossing signals and gates.  They have worked flawlessly for several years.

 

I built an 8 block bidirectional signal system using an Arduino Mega triggered by my optical detection system, again it works flawlessly.  It isn’t complicated just a simple truth table concept.  It will drive 16 three color LED signal heads.

 

http://melvineperry.blogspot.com/2017/02/february-3-2017-arduino-mega-signal.html

 

Good Luck!

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[gregc]

i successfully built a current detector, i think from Paisley's design using the transformer he described.  I think  it's one of the Vitec transformers on 

http://www.surplussales.com/class/inductor/current.html

that design used a 555 or 556.   I'll try to post a schematics after I get home.

[7j43k]

Free-mo uses a relatively simple system to do ABS signaling.  There is no computer. There are normally no relays.  

Detection is with a current sensor such as the NCE BD-20.  In addition there is optical detection at each block boundary.  I use the Iowa Scaled Engineering CKT-IRSENSE.  The system integrates both types of detection.

There is no need to add resistors to rolling stock.

I expect it will also interact with interlockings.  I will eventually build one and will find out.

The system works very nicely.  You get the appropriate red, yellow, green colors at the appropriate time.  You can also do flashing yellow and/or approach lighting, though I haven't gotten into that.  

There is no practical limit to the number of blocks.

 

Ed

[gregc]

i believe this is the circuit and description

[richg1998]

Maybe a moot point now but I saw a discussion a few days ago in the MRH forums. Someone found this link. A search for domain on web.archive.org

http://web.archive.org/web/20140921121552/http://home.cogeco.ca:80/~rpaisley4/CircuitIndex.html

Rich

[rrinker]

 Curious Mel what you mean by the current sense didn't work like you wanted means. For signal control I wouldn;t want anything but - since it doesn;t matter where in the block something is, it is detected. Even a siding entering somehwere in the middle, or you 0-5-0 a car or loco to the middle of the block.

                         --Randy

 

[RR_Mel]

rrinker

 Curious Mel what you mean by the current sense didn't work like you wanted means. For signal control I wouldn;t want anything but - since it doesn;t matter where in the block something is, it is detected. Even a siding entering somehwere in the middle, or you 0-5-0 a car or loco to the middle of the block.

                         --Randy

 

 

Randy

 

I just don’t like having to have current sense through the wheels of my rolling stock.  I’ve used current sense successfully since the 60s with the Twin-T.  Current sense always worked very well for my block signaling.

 

I also used Rob’s current sense circuits but having to have every car to draw current just didn’t do it for me.  As far as using current sense Rob’s circuit works extremely well.  I still have them installed I just don’t use them any more.

 

All of my cabooses have lighting so current detection will work on my layout.  Several blocks are short in length so cars in the middle need to draw current or my signaling goes berserk.

 

I ran with dual detection for a couple of years and finally went to all optical.  I was using across the track optical detection for spotting in hidden areas and it worked so good I just decided to do it to it.

 

There was a problem hiding all the sensors and emitters but the end product works very good for me.  I ended up having a lot of fun hiding emitters and receivers all over the place, trees, bushes, buildings, signal cabinets, rocks and signs.  My great grand kids have a blast blocking the beams tripping my signal system and making the crossing gates go up and down.

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

[7j43k]

FWIW.

As I said earlier, Free-mo does block detection without current sensing through the rolling stock.  It is very reliable.

Thought that might be of interest to someone.

Ed

[rrinker]

 As we do on our club layout. Wasn't a huge deal to put resistors on my wheels - I use all metal wheels anyway. The total current draw is next to nothing, even with hundreds of cars. Typical resistance is 10K. At a typical 15V DCC voltage, that's about 1.5mA per car, 100 cars is 150mA but that is spread out across multiple blocks.

 Current detection doesn;t work as well with DC, because the current varies witht he votage and thus speed, plus if the train is stopped, there's no current flow. This is usually fixed by supplying a small bias voltage. Bruce Chubb's original Optimized Detector demonstrates one way. Note that the bias voltage must bypass and block toggles as well, or else you would need to use another pole on the switch to mark every powered off block show occupied.

 All of course non-issues with any control system that has a constant voltage on the rails, like DCC.

The transformer method is superior to the diode drop method, simply because there is no voltage drop, and you don't need to do anything special with non-detected blocks so that train speed doesn't vary.

Point detection with IR or similar is much easier for things like grade crossing flashers and avoids having to figure out ways to connect multiple block detectors into one for signalling purposes while keeping them seperate for the purpose of triggering the crossing gates. Both types have their places. 

                              --Randy

 

[Mark R.]

You can use a web crawler to gain access to the original site ....

http://web.archive.org/web/20160320155749/http://home.cogeco.ca/~rpaisley4/CircuitIndex.html

Most all of it seems to be intact, but save what you can now is case it too goes away.

Mark.

[cwobosn]

I really apprecaite all the feedback!!! I will look into the different methods and see which one will work for me.  There are so many different options out there.

Thanks again, Mike

[DOCA]

I think you will find Rob's materials now at circuitous.ca/Circuitindex.html#61

 

Carl

[richg1998]

DOCA

I think you will find Rob's materials now at circuitous.ca/Circuitindex.html#61

 

Carl

 

Welcome.

URL no good. Try it.

You need to post the "full" URL.

http://www.circuitous.ca/CircuitIndex.html

 

Rich

[MisterBeasley]

I bought a couple of grade crossing detection circuits from Rob.  He worked with me as I tried to make the system work with infrared.  I bought the circuits built-up and they worked perfectly.

[richg1998]

Some years ago I bought his circuits for the DCC amp meter and they work just fine with the Harbor Freight multimeters.

I used one for the club with a large LED readout so we can see the DCC current from about any where in the room.

Rich