The FK501 initiates an alarm signal through an in-built speaker when its photo transistor detects a light level change. To prevent transient light changes giving false alarms an adjustable delay timer has been incorporated.

Technical Specification

  • Power Supply : 9VDC @ 40mA (working)
  • Delay ON Adjustment: Approximately 30-50 seconds.
  • PCB Dimensions : 2.80" x 1.55" x 0.6" (71.1mm x 39.4mm x 15mm)
  • Recommended Housing : FB03