3 in stock
OC1 Quad DCC Occupancy Detector
The OC1 is a four-segment DCC block occupancy detector.
It is completely powered from DCC, and provides four optically-isolated outputs with a common ground.
The advanced microcontroller design allows for previously unavailable occupancy detection features, including compensating for the unoccupied current level and easy sensitivity setting in small calibrated steps.
A single axle with a 10 kΩ resistor between the wheels can be reliably detected.
Zero Level Compensation
After you connect the OC1 to DCC power and the track segments, you remove everything from the track and press the button (see operations section for details).
This measures the current when the track is unoccupied and saves these value for each segment in the digital memory of the processor.
During normal operation, the saved zero levels are subtracted from live readings before determining whether a segment is occupied.
This greatly reduces false readings due to leakage and capacitive coupling such as from twisted pair wires.
Adjustable from 1/4 milliamp (mA) to 3 3/4 mA in 1/4 mA steps.
For reference, a single 10 kΩ resistor accross the track draws from about 1 mA to over 2 mA depending on the DCC voltage.
Optional 2-Second Hold Time
The unit can be configured to hold all occupied indications for at least 2 seconds, or to make the outputs immediate.
Supports up to 4 amps current per segment.
The outputs are completely isolated from the DCC power via opto-couplers.
Occupied indicator LEDs for each segment.
Low Voltage Drop
The electronic sensors drop only 400 mV at full current and less at lower current.
25 mA Output Sink
The open-collector outputs can sink 25 mA, allowing most common LEDs to be driven directly without additional relays or transistors.
Drive Digital Logic Inputs
Can drive digital logic inputs with only a single added pullup resistor per segment.
Easy connection of up to 12AWG wire for power inputs, block detection inputs, indicator outputs.