Subway Layout 2.0 Progress - Current Detectors and Signals (95/123 Total)

Awesome work! I would have used an Arduino module, but yours is up and

running, while mine is just on paper...

Arduino would be nice.  For this section I guess the Uno version would suffice.  I would be unable to use my regulated 5 volt DC power for the board because the specs state that it requires between 7 and 12 volts DC.  My controller uses one 7400 quad NAND gate chip and one hex inverter 7400 chip each supplied by 5 volts DC power.  I guess it would not make a difference if I used a different voltage for DC power as the only thing I would need to do is change the values of the current limiting resistors for LEDs.

My worry with Arduino is its durability to withstand the many mistakes made as electronic hobbyists.  I have many times accidentally shorted my DC supply voltage or created solder bridges. Situations like that would play havoc on an Arduino I think.  It is also easy to destroy an IC chip, but they have performed near flawless regardless of the mistakes I make.  If I destroy an Arduino Mega (as some of the more complicated modules would require) I am out $50.

Actually, my first stillborn signal controller was pre-Arduino, but used the same

basic chip: an Atmel ATMega CPU. Easy enough to swap out the controller on the module should it gets zapped. But it's still pretty hard on those chips. But a

replacement CPU for an Arduino module is also cheap: about 3 bucks.

Here is Section 6 on the "A" line.  There are 3 tracks, 2 Local and 1 express.  Each is a block containing a single current detector.

The "B" line has 5 blocks (not shown).  Normally I would construct a single board containing 8 current detectors for the entire section.  However I have single detectors on a Radio Shack dip perfboard that I used on my previous layout.  I have additional additional hardware that I wish to reuse also.  So I constructed a triple current detector accessory board with reused parts.  There is no controller in this circuit, so there are 6 outputs, 3 for the section 6 controller yet to be built (white labels), and 3 of the same outputs (gray labels) for neighboring sections.

Section 4 has 4 blocks, so there is a quad-current detector used for train detection.  This is a 2 track section where there are 2 blocks for each direction. 

Detector outputs DA4-01 and DA4-04 are duplicated and designated in gray. These outputs will be used by neighboring sections.

Elevated section 6B has 5 current detectors. It is part of a proposed elevated station where detectors DB6-01 and DB6-02 are in the station and DB6-03 is on a layup track. Detectors DB6-04 and DB6-05 are on express tracks on the upper level. So it is a double elevated structure.

The 5 current detectors are constructed by reusing detectors from my previous layout. There are accessories for station, street, and building lighting. All detector outputs are duplicated and used in neighboring sections.

Very nice.

Thanks again 

Subway signal molds look good.  I assume they are O-scale. Tunnels lights do not have hoods over lenses, only on elevated lines.

Here is Section 03 of the new layout.  The track design is for BOTH subway and elevated.  The elevated line will have a two tier design (double el) and support part of a station.

There will be a 12 block current detector to control the signals (7 subway(A), 5 elevated(B)).  Additional accessory lighting is also supported by the circuit for station lighting, tunnel lights, buildings, and streets. Outputs will also be used by signals in adjoining sections.

what parts do you use for detectors 

Calabresse94 

Please go to Integraated Signals Systems.com They have all types of Transit Signals and Track detectors systems.

Good Luck ! John

Well I'm back at building these detectors. I have 123 to build and am nearly done with 95.  The parts list consist of building a basic current detector using an 8-amp bridge rectifier, 120K, 330, and 33 ohm resistors, a 2506 optoisolator, 555 timer, 0.1 micro farad capacitor, 10 micro farad electrolytic capacitor, and a 0.01 micro farad capacitor. The current detector design was derived from this documentation.

http://www.gatewaynmra.org/199...on-systems-circuits/

Do these current detectors interfere with the DCS or TMCC signal?

These detectors will work in conventional mode only. I think with DCS or TMCC there would be a continuous detection and render these detectors useless.  That is my understanding, but if there is someone more knowledgeable please interject.

Joe, 

Integrated Signal Systems has good Track detection products too.

When someone purchases my Transit Signals, I supply them with my Wiring Diagram  

.

Good Luck,

Thanks John

This is subway Section 1A of the layout. This configuration is quite complex as there are switches to the looped station in Section 5 or the continuous oval.  There is an additional switch to a non-electrified stub end that will be used to add trains to the layout.  Also section 1AB is part of the ramp that will connect the subway section (A) to the elevated section (B).  There are 9 blocks in this section.

This is section 1B which is the elevated portion.  There are 3 blocks.

Section 01 uses a 12 block current detector, one for each block, as well as for accessories such as circuitry for structure, street, and station lighting. Also some outputs are used for neighboring sections.

This is subway Section 2A of the layout. Also section 2AB is part of the ramp that will connect the subway section (A) to the elevated section (B).  There are 5 blocks in this section.

This is elevated section 2B of the layout.  There are 4 tracks here where the middle 2 tracks are a ramp to the double elevated section and there are 8 blocks.

Section 02 uses a 13 block current detector, one for each block, as well as for accessories such as circuitry for structure and street lighting. Also some outputs are used for neighboring sections.

While these designs seem repetitive, they are crucial for my signalling system. These current detectors are of the bridge rectifier variety and will knock down track voltage by 1.4 volts.  This design also accepts a 12VAC trickle voltage which will allow for current detection should there be no transformer power to the rails.  This is designed for conventional mode.

Section 10A is illustrated here.  The design allows for 3 detectors in the subway and 2 more for the ramp to the elevated.

Section 11A is designed with 8 detectors. There are 3 in the tunnel, 3 in the station that straddles Sections 11A ans 12A, and 2 on the ramp to the elevated.

Sections 10B and 11B are the elevated section.  Each section contains 3 detectors and an elevated station straddles both sections.

Here is the circuit for Section 10.  These are 2 circuits separated by parts A and B.  The reason for this design is that I decided to reuse components from my old layout.  This is done for Sections 6, 7, and 8 also.  Part A has 5 detectors as well as resistors for tunnel lighting.  Part B has 3 detectors with resistors for station, street, and structure lighting. Detector outputs are also available for neighboring sections.

The circuit for Section 11 is a combination of both parts A and B.  There are 14 total detectors.  The resistors control lighting for BOTH stations on the elevated and subway portions, tunnel, structure, and street lighting.  Detector outputs are also available for neighboring sections.