Loop Detect Circuit (A-Lead Control) (Model LDB-1)

Viking offers a loop detect board with contact outputs capable of handling up to 500mA. The LDB-1 will be more robust than current A-Lead control's available in the marketplace.
Loop Detector Board with on board 12 Volt Regulator
The LDB-1 provides a loop activated contact closure when used in series with telecom devices on analog phone lines. The LDB-1 will initiate a dry relay contact on any off-hook condition. Alternatively, add the optional PS-2 power supply to provide switched DC power.

The relay itself is phone line powered and does not need an external power supply. Because both TIP and RING currents flow through the relay, excellent line balance is maintained.

  • A-Lead Control
  • Line "In-Use" detector/indicator
  • Phone line powered
  • Excellent line balance
  • Optional PS-2 power supply for switched power
  • Made in the USA
  • 1 Year Warranty
  • Dimensions: 47.6mm x 30.5mm (1.875" x 1.2")
  • Mounting: (2) #4 screws (not included) or foam tape (included)
  • Shipping Weight: .45 kg (1 lb.)
  • Added Loop Resistance: 40 ohms
  • Maximum Loop Current: 125 mA
  • Minimum Loop Current: 18 mA
  • Operating Temperature: 0° to 70°C (32° to 158° F)
  • Maximum Supply Voltage Input: 35 V DC
  • Maximum 12V Supply Current: 500 mA with PS-2
  • Longitudinal Balance: 63 dB minimum
  • Maximum Contact Voltage: 200 V DC
  • Maximum Contact Current: 500 mA
  • Maximum Contact Power: 10 W
  • Connections: 7 pin screw terminal block