Loop and Ring Detect Board for Ring and Line inIn Usein Contact Closures. The LDB-2 Ring/Loop Detector monitors an analog phone line for ringing or an in-use condition. A built-in relay can be activated when either of these conditions are detected. This is ideal for monitoring line status or for providing a visual indication of such. When monitoring for ring, an internal pot can be adjusted to allow the relay closure to stay on steady, or follow standard ring cadence. The LDB-2 comes complete with a 12 VDC power adapter, and can also provide 12V DC power through its auxiliary 12V DC output terminals. Applications Control a strobe light for ring indication Provide relay closures on ring and off-hook Trigger a security camera Trigger a tape recorder Phone in useindicator Features Detects ring voltage and loop connect Screw terminal connections Wall mountable with foam tape (included) or screws (not included) Auxiliary 12V DC output Adjustable time-out for relay closure Two sets of relay contacts provided Selectable NO (normally open) or NC (normally closed) relay contacts Made in the USA 1 Year Warranty.