BD-20 DCC Block Detector 

[visit NCE Corp. catalogue page]

• No connection to track, not optical
• Not intrusive, does not use track power
• Compatible with all DCC systems up to 20 Amps/booster
• Broad adjustment range by user
• Economical starting at $11.95

The BD-20 block detector module is normally used to indicate the presence of a locomotive, caboose or other rolling stock in a tracl section by sensing electrical current drawn by that rolling stock. Locomotives will naturally trigger the detector because they draw current through their DCC decoder. Unpowered rolling stock will not trigger the detector unless equipped with some means of drawing current from the rails such as lights or a resistor wheel set.

Unlike other detection units the BD-20 requires no direct electrical connection to the track. This block detector can be used with any sized DCC power booster of up to 20 Amps capacity. The track feeder wire for one rail of the block is just passed through the hole in the current transformer on the module (see figure 1) before connecting the feeder to the track. The more times the wire goes through the hole in the current transformer the more sensitive the detector becomes.

An LED can easily be added for simple indication of staging track occupancy, progress through a helix, etc. The LED indicator requires a DC power supply of between 5 and 15 Volts to power the LED. You don't need this power if you don't use the LED option

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