Model Railroad Control Systems
Model Railroad Control Systems

MRCS-Optical-Detector

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Ambiant light optical detector based on GBunza DAPD with Chubb style hysteresis

 

 

MRCS-Optical-Detector Version 1.1

First built: 2017-12

DFM, PTH parts, offboard detectors…

Schematic
Schematic
Bot Silk
Bot Silk
Board
Board
Top Silk
Top Silk

Download MRCS-Optical-Detector - CHMT Component and feeder definitions
Download MRCS-Optical-Detector.gerbers.zip - Gerber Fabrication files
Download MRCS-Optical-Detector.parts - Parts List (spreadsheet data)

 

MRCS-Optical-Detector.bom

Parts Value Package Quantity Library Type/Feeder
C1 1 uF Tant E2.5-5 1x rcl PTH
R8 1K AXIAL-0.4 1x SparkFun-Resistors PTH
D1 1N5819-B DO41-7.6 1x diode PTH
R4 2M AXIAL-0.4 1x SparkFun-Resistors PTH
T2 2N4401 TO92-EBC 1x transistor-neu-to92 PTH
R2 5.6K AXIAL-0.4 1x SparkFun-Resistors PTH
R1, R5, R6, R7 10K AXIAL-0.4 4x SparkFun-Resistors PTH
R3 100K AXIAL-0.4 1x SparkFun-Resistors PTH
U$3   CA-PROP65WARNING 1x MRCS-prop65warningBtm PTH
U$1   MRCSLOGOBTM 1x MRCSLogoBtm PTH
JP1 Detectors 1X04_LOCK 1x SparkFun-Connectors PTH
IC1 LM2903N DIL08 1x linear PTH
JP2 Output 1X04_LOCK 1x SparkFun-Connectors PTH
T1 PT19 BPX81 1x opto-trans-siemens PTH

Documentation

Optical Position Detectors are useful when precise position detection is required (clearing a staging throat, for example), when the area to be detected is small (an “OS” section in a CTC system) or where resistance wheel sets cannot be applied and current detection can’t be used. The Enhanced Optical Position Detector is based on Geoff Bunza’s DAPD and provides a fixed turn-on and turn-off delay and high power output stage similar to Bruce Chubb’s DCC-OD (so if you need an optical detector that’s electrically compatible with a cpOD or DCC-OD, EOPD is for you!).

The EOPD uses Geoff’s self-calibrating detection circuit, so you don’t need to adjust for ambient light level. Note the circuit won’t work in the dark unless you substitute infrared Photo transistors and provide an infrared illumination source. The supply voltage range is 5-15 volts and the output is a active low (0/gnd is true) open collector which will sink up to 600 mA at up to 40VDC. Size is 1.15” x 1.75 x 0.5” high”

Either 2 PT-19 photo transistors or “Da Fingah” will work with this board. One is used as an ambient light reference and another is placed between the rails. You may solder the reference photodetector onto the board if the board will be mounted where is has the same illumination as the track or both may be mounted remotely.

This detector is compatible with the Modular Signaling System (MSS) Optical Detector

doc

Optical Position Detectors are useful when precise position detection is required (clearing a staging throat, for example), when the area to be detected is small (an “OS” section in a CTC system) or where resistance wheel sets cannot be applied and current detection can’t be used. The Enhanced Optical Position Detector is based on Geoff Bunza’s DAPD and provides a fixed turn-on and turn-off delay and high power output stage similar to Bruce Chubb’s DCC-OD (so if you need an optical detector that’s electrically compatible with a cpOD or DCC-OD, EOPD is for you!).

The EOPD uses Geoff’s self-calibrating detection circuit, so you don’t need to adjust for ambient light level. Note the circuit won’t work in the dark unless you substitute infrared Photo transistors and provide an infrared illumination source. The supply voltage range is 5-15 volts and the output is a active low (0/gnd is true) open collector which will sink up to 600 mA at up to 40VDC. Size is 1.15” x 1.75 x 0.5” high”

Either 2 PT-19 photo transistors or “Da Fingah” will work with this board. One is used as an ambient light reference and another is placed between the rails. You may solder the reference photodetector onto the board if the board will be mounted where is has the same illumination as the track or both may be mounted remotely.

This detector is compatible with the Modular Signaling System (MSS) Optical Detector

This technical documentation is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike

Tags: eagle MRCS