NEXSYS® Component Technology – Sensors & Detectors

Time Delay

Time Delay

The TIME DELAY from Applied Avionics is a 4-pin device which can output a delayed Ground or Open signal initiated after a specified input trigger event. The changed output signal will persist until the trigger condition is reversed. The input trigger event can be a change of state on the INPUT line or a unit power-up. This device is part of our NEXSYS® Component Technology products and is configurable inside of a VIVISUN® switch/annunciator or a NEXSYS Module.

The TIME DELAY is designed, tested and qualified to applicable military standards. The Time Delay also meets the environmental requirements of DO-160.

  • Available as Time Delay on Trigger or Time Delay on Power-Up
  • Timing options from 125 ms to 4 hours
  • Configurable inside VIVISUN® High Capacity and Compact switch bodies and NEXSYS® Modules
ARINC 429 Block Diagram

How it Works

Time Delay on Trigger

There are three operating states of the TIME DELAY.

  • “STANDBY” (RESET) – Unit is powered, input (PIN 3) is at the standby level. Output (PIN 1) is the opposite polarity to the specified output when unit is “ACTIVE.” The timer is held RESET at 0 until the STANDBY is released.
  • “DELAY” – Unit has received an input trigger event starting the time delay. During “DELAY” the Output (PIN 1) remains the same as “STANDBY.” The trigger event to change the state from STANDBY to DELAY is when INPUT changes from the STANDBY level to the DELAY/ACTIVE level. There are four unique specifiable operating states for the INPUT line. Also, the DELAY state will be automatically triggered on power up if the Input (PIN 3) is at the DELAY/ACTIVE level. The output will return immediately to the STANDBY condition and the timer will be reset to 0 whenever the INPUT is at the STANDBY level.
  • “ACTIVE” – Output (PIN 1) is the specified output signal (Ground or Open) once time delay has been completed.

The TIME DELAY requires constant power (+28 VDC) on PIN 2 and Ground on PIN 4 for proper operation. If power is removed from PIN 2, the TIME DELAY output (PIN 1) will be Open.

Time Delay on Power-Up

Time Delay on Power-Up, there are two operating states of the TIME DELAY. INPUT (PIN 3) is not used (operating state code X).

  • “DELAY” – Powering up the unit (+28V applied to PIN 2) acts as the trigger and delay timer starts running. Output (PIN 1) during “DELAY” is the opposite polarity to the specified output when unit is “ACTIVE.” PIN 1 will transition to “ACTIVE” state when time delay is completed. If power is cycled when unit is in “DELAY,” the timer will restart. If desired “ACTIVE” state is Open, Output will become Ground at power-up; if desired “ACTIVE” state is Ground, Output will remain Open (non-powered state) at power-up.
  • “ACTIVE” – Output (PIN 1) is the specified output signal (Ground or Open) once time delay has been completed.

Component Features

There are two primary types of TIME DELAYs.

  • Time Delay on Trigger: Delay timer starts after a level change of the INPUT line. Typical applications can be for “battery-saver” when a delayed power-off condition or delayed activation of a control is desired.
  • Time Delay on Power-Up: Delay timer starts upon power-up. Typical applications include using the timer to stagger various system start-ups to avoid spikes that occur when multiple systems are energized simultaneously.

For each TIME DELAY, the output signal (PIN 1) can be specified as either Ground or Open when the unit is “ACTIVE.” The TIME DELAY requires constant power (+28 VDC) on PIN 2 and Ground on PIN 4 for proper operation. If power is removed from PIN 2, the output signal (PIN 1) will be Open.

There is a wide range of timing options available in: milliseconds 125*, 250*, 500; seconds: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30; minutes: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30; or hours 1, 2, 4. *These delay timings are not available with the Time Delay on Power-up.

Time Delay – Application Examples

To help system designers understand the potential of NEXSYS Component Technology, we have assembled a collection of Application Notes. The links below show example applications that utilize the Time Delay component.

Battery Saver Staggered Power-up