This page shows a successful attempt to operate block occupancy detectors for DCC systems in a closely spaced group and with cabled wiring.
All of the detectors in this test functioned correctly with no evidence of interference between units. The detection sensitivity of the circuit is just under one milliamp.
The detectors are a diode - voltage drop type. These detectors are designed to operate on DCC systems.
The DCC only design was chosen in order to reduce the parts count and therefore the cost per block. All of the parts used are widely available.
ORANGE = supply to the circuit - BLUE = signal wire from block - YELLOW = common of circuit and block system.
The LEDs indicates a train detection. The output is optoisolated.
The individual circuit boards were left attached for ease of installation.
The explanations for the circuits on these pages cannot hope to cover every situation on every layout. For this reason be prepared to do some experimenting to get the results you want. This is especially true of circuits such as the "Across Track Infrared Detection" circuits and any other circuit that relies on other than direct electronic inputs, such as switches.
If you use any of these circuit ideas, ask your parts supplier for a copy of the manufacturers data sheets for any components that you have not used before. These sheets contain a wealth of data and circuit design information that no electronic or print article could approach and will save time and perhaps damage to the components themselves. These data sheets can often be found on the web site of the device manufacturers.
Although the circuits are functional the pages are not meant to be full descriptions of each circuit but rather as guides for adapting them for use by others. If you have any questions or comments please send them to the email address on the Circuit Index page.