TSD Series OFF-Delay Solid-State Output Timer

The TSD Series OFF-Delay Solid-State Output Timer from the ATC Diversified Electronics division of Marsh Bellofram Corporation is a family of rugged, high-reliability OFF-delay solid state output time delay relays (TDRs), available in both fixed and adjustable time versions. Voltage is continuously applied to the input, while an external isolated switch controls the timer. When closed (momentary or maintained), the load energizes and the delay period begins. Upon completion of the delay period, the load de-energizes. When closed, the load energizes. Opening the switch initiates the delay period. If the control switch recloses during the delay period, the load remains energized and the timer resets to zero.



  • External control switch controls timer
  • Fully encapsulated
  • Fixed and adjustable time versions


  • Industrial machinery and equipment
  • Conveyor belts
  • Exhaust fans
  • Heating systems
  • Lubricators
  • Pump and motor controls
  • Flashing light control
  • Engine auto start control