NEXSYS® Component Technology – Sensors & Detectors

Square Wave Oscillator

Time Delay

The SQUARE WAVE OSCILLATOR from Applied Avionics is a 4-pin device which can output a signal that oscillates between Open and Ground at a specified rate. The oscillating function will become active based on the state of an input line and will persist until the state of the input line is reversed. This device is part of our NEXSYS Component Technology and is configurable inside of a VIVISUN switch/annunciator or a NEXSYS Module.

The SQUARE WAVE OSCILLATOR is designed, tested and qualified to applicable military standards. The SQUARE WAVE OSCILLATOR also meets the environmental requirements of DO-160.

  • Options include four oscillation functions and eight oscillation rates
  • Configurable inside of VIVISUN® High Capacity and Compact switch bodies and NEXSYS® Modules
ARINC 429 Block Diagram

How it Works

There a two operating states of the SQUARE WAVE OSCILLATOR.

  • "STANDBY” – Unit is powered, but output signal (PIN 1) is in its steady state based on the state of the INPUT line. In the STANDBY state, the output can be specified to be either Ground or Open.
  • “ACTIVE” – Based on the INPUT line (PIN 3) moving to the Active state, output signal (PIN 1) is oscillating between Open and Ground at the specified oscillation frequency. Output (PIN 1) will return to STANDBY if PIN 3 returns to the STANDBY state.

Component Features

Output Signal

When oscillating function is ACTIVE, the output signal (PIN 1) will oscillate between Ground and Open. The output signal (PIN 1) can be specified to be either Ground or Open when oscillating function is in STANDBY state.

The SQUARE WAVE OSCILLATOR 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 (PIN 1) will be Open. At power-up, the oscillating function will be STANDBY or ACTIVE based on the state of the INPUT line (PIN3).

Oscillation Function

Oscillation of the output (PIN 1) is determined by the state of the INPUT line (PIN 3). There are 4 possible combinations of state that can be specified to activate the oscillating output.

Input Line Options (PIN 3)
Oscillation STANDBYOscillation ACTIVE
+28 VDC or OpenGround
+28 VDC
Must be same power source as PIN 2
Ground or Open
Ground or Open+28 VDC
Must be same power source as PIN 2
Ground+28 VDC or Open

Oscillation Frequency

Oscillation rate can be specified from the eight options below:

(Cycles / Sec.)
(Sec. / Cycle)
500 Hz0.002
100 Hz0.01
10 Hz0.10
4 Hz0.25
1 Hz1
0.5 Hz2
0.25 Hz4


Square Wave Oscillator – 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 Square Wave Oscillator component.

Custom Blink Time Limit Switch