Blink Advisory Indicator DiagramClick to Zoom

This circuit detects a fuel tank over fill condition. When an over fill occurs a limit switch trips and a blinking advisory is initiated. The Blink mode continues until the over fill is corrected resetting the limit switch. The circuitry for this system is self-contained in a single indicator body.

This application utilizes a single VIVISUN High Capacity Body that contains a NEXSYS (8-Pin) Electronic Latch (EL2) and (4-Pin) Solid State Relay (SSR1H). The EL2 differs from the EL1 product in that its BLINK output is active upon power up. The EL2 device in this example is energized by the SSR1H to produce a BLINK output to the VIVISUN LED indicator when the SSR1H receives a ground input from the Tank Overfill switch. The indicator remains in the BLINK Mode until the Tank Overfill switch opens.

In the schematic, +28VDC is applied to the (H2) input and (H1) output of the SSR1H. When the remote Tank Overfill switches the ground signal to the (H3) input of the SSR1H, the internal solid state conection of the SSR1H closes and the +28VDC signal passes from the (H4) output of the SSR1H and is applied to the (J4) input of the EL2. This powers up the EL2 with the BLINK output active. This drives the “AUX TANK OVERFILL” (Pin D) indicator to blink at 1Hz. When the Tank Overfill switch goes High Impedance (OPEN), the LOGIC circuitry is turned off and the blink is extinguished.

This example demonstrates how NEXSYS LOGIC Component Technology may be combined with a VIVISUN High Capacity Body to produce a blinking LED indication when triggered by a remote signal. The blinking output may also be reset by a remote trigger. This application is especially useful under CAUTION/WARNING conditions wherein a BLINK state would enhance the attention-getting properties of the LED indicator.

This application of the EL2 and SSR1H components eliminates the need for an external relay which would be required to sense and trigger other components, such as the BLINK generator in this case. The above example may also include a momentary switch to reset the blinking LED Indicator to either steady illumination or reset to the off mode. In addition, to driving the 1 Hz blink, an aural advisory could also be added to the circuit.

Disclaimer: The configurations and diagrams shown above are provided by Applied Avionics, Inc. as a general example only. The recipient is solely responsible for actual design, electrical wiring, validation, testing, applicability and functionality of the product in regards to the customer’s specific application.