Frequently Asked Questions
- LED Advantage
- What are the advantages of using the VIVISUN LED switch?
There are numerous advantages. In particular: high reliability, with virtually zero maintenance required. Plus new features, like simple voltage-controlled dimming, which offers exceptional readability no matter what your lighting conditions, and the DichromaticSwitch™, which has bicolor legends that can be illuminated in two distinctly different colors. The VIVISUN LED features a fault tolerant circuit design, offering low power consumption and low heat. Our switches are MIL-SPEC qualified, easy to install, and they serve as a direct replacement for existing switches. All VIVISUN switches are manufactured under a proven quality assurance system that ensures defect-free products, outstanding customer service and delivery when you need them. Best of all, they are readily available now.
- Where should I use VIVISUN LED lighted pushbutton switches and indicators?
Use VIVISUN switches wherever man-machine interface lighting is critical. Currently they are used extensively in military, commercial and general aviation cockpits. They serve FAA mandates and are used as upgrades for a wide range of aircraft, as well as in ground vehicles, security systems and on shipboard controls.
- What illuminated colors are available in the VIVISUN LED?
We provide 11 sunlight readable colors, including standard aviation green, yellow, red, white and blue. NVIS colors include green A, green B, red, yellow, white and blue. Every color provides the same exceptional quality and readability.
- What about touch temperature?
The VIVISUN LED uses low power, solid state lighting that emits far more light than heat. This significantly lowers the face cap temperature compared to similar incandescent switches and indicators. In normal operation, the face cap temperature is only 48° C, which is barely perceptible to the touch.
- What about LED reliability?
Our results speak for themselves. The reliability of our LED has been established through MIL-SPEC Qualification testing and in-service use, and it's backed by the reputation we’ve built over the past 40 years. The VIVISUN LED product MTTF is in excess of 125,000 hours as calculated per MIL-HDBK-217F, Notice 2. Our high-reliability design operates virtually maintenance free for the life of the avionics platform. With the VIVISUN LED, there are no aircraft downtimes for replacing incandescent lamps, and no other routine switch maintenance is required.
- How is the luminance controlled to provide both high brightness sunlight readability and very low luminance needed for night conditions?
Simple voltage adjustments are made directly to the switch internal lighting circuit to regulate a smooth and uniform luminance from high to low brightness (voltage-controlled dimming).
- Can lighting be both sunlight readable and NVIS compatible?
Yes, this is a requirement for modern, state-of-the-art cockpits. Both features are built into the VIVISUN LED through voltage-controlled dimming, which works by simply regulating the applied voltage.
- What advantages does the QUIK-CONNECT™ Common Termination System (CTS) provide?
The CTS module is an environmentally sealed, solderless, keyed, easy to install, bench testable wiring system that snaps directly into the rear of the switch without the use of tools. The CTS module is stocked and ready to ship ahead of your custom switch, thus allowing the CTS module to be inserted into the wiring harness prior to installation onto the platform (pre-wired).
- If I presently have Aerospace Optics VIVISUN 95 Series incandescent installations, can I upgrade to the VIVISUN LED lighting?
Yes. Mechanically, the LED pushbutton cap is interchangeable with the existing 95 Series incandescent pushbutton cap and uses the same MIL-PRF-22885/108 QPL listed switch body.
- Customization
- What switching capabilities are available?
You can select either momentary or alternate action switches, with one to four poles, single or double break, and with silver or gold contacts. Our indicators (no switches, no action) are available with all of the same lighting characteristics, colors, mechanical features and reliability performance.
- Can I design my circuitry to meet specific needs?
Yes, our customers can specify their desired circuit polarity, interconnection style (reduce external wiring), and choice of common or split ground, with quadrant redundancy for fail-safe lighting.
- Performance & Specifications
- What can I expect with regard to display legibility and uniformity?
Second to none. From daylight conditions to nighttime flying levels, the entire legend will be uniform at the desired luminance and maintain excellent color distinction as the voltage input is regulated. At full rated voltage the average character-to-character luminance uniformity ratio will be better than 2:1.
- What about viewing angle?
The VIVISUN LED has a wide 120-degree viewing angle in sunlight conditions.
- Does the NVIS product meet military requirements?
Yes. Our switches are certified in accordance with MIL-STD-3009, as previously defined in MIL-L-85762A, and requirements are verified by spectroradiometry.
- Do the LEDs have reverse polarity protection?
Yes. LEDs are PN junction semiconductors that are inherently sensitive to polarity. The VIVISUN LED is available in either common cathode (positive seeking) or common anode (negative seeking) configurations, each having reverse polarity protection.
- What about power consumption?
The power consumption for the standard ¾-inch LED is 1.18 watts at 28 VDC. The power consumption for the 1-inch by 1.2-inch LED is 1.5 watts at 28 VDC. The VIVISUN LED switches reduce power by more than 50% over a typical 2.69-watt incandescent switch. Reducing the wattage reduces the heat and improves reliability. At full power the touch temperature is ergonomically cool and meets the requirements of MIL-STD-1472.
- What about current draw?
The current draw for the standard ¾-inch LED is 42 mA at 28 VDC. The current draw for the 1-inch by 1.2-inch LED is 54 mA at 28 VDC.
- Are switches protected from electrical environmental hazards?
Yes. VIVISUN LED switches meet DO-160 electrical environmental requirements with regard to voltage spikes, magnetic effects, lightning strikes, induced and emitted signals, ESD immunity, HERF issues, power surges and other issues that necessitate electrical protection.
- What is needed for installation?
Each VIVISUN LED is supplied with a mounting spacer and mounting sleeve for simple, effortless installation. All retaining hardware for the switch is provided internally, allowing easy mounting from the front of the instrument panel with a small screwdriver.
- Can I purchase an environmentally sealed switch?
Yes. You can specify a unit that is dustproof, dripproof, watertight and splash-proof.
- Is there an EMI/RFI attenuation option?
Yes. When specified, the VIVISUN LED switches meet the MIL-PRF-22885F paragraph 3.38 requirement for shielding attenuation not less than 60 dB over the frequency range from 100 to 1000MHz when tested as specified in paragraph 4.7.33.2.
- How many LED light sources are used to manufacture each pushbutton cap?
The standard ¾-inch switch features 16 LEDs in each cap and the 1-inch by 1.2-inch switch features 24 LEDs in each cap. This provides excellent viewing angles, luminance uniformity and life-of-the-platform reliability, as well as flight-critical, fault-tolerant, fail-safe lighting.
- Is there a way to indicate more than one condition with a single switch legend?
Yes, the DichromaticSwitch™ has bicolor legends that can be illuminated in either of two distinctly different colors. For example, you can have a legend turn yellow to indicate a caution condition and later turn red to indicate a warning condition on the top half of the switch, and use the bottom half of the switch for a different function altogether.
- What happens in the event of an LED failure (open circuit)?
Each pushbutton cap contains four independent lighting quadrants. A quadrant's electronic circuit includes four LEDs and an independent Driving, Dimming and Protection Circuit (DDPC). In the unlikely event of an LED failure, a quadrant would lose lighting from only two LEDs and continue to maintain legend readability.
- Service
- What about your Quality Assurance System?
Aerospace Optics is ISO 9001:2008 and EN/JISQ/AS9100:2009. We have supplied high quality lighted switches to military, commercial and general aviation customers for 40 years. Our quality, technology and ongoing efforts to continually improve pushbutton switches and cockpit lighting are favorably recognized throughout the industry.
- What promises does Aerospace Optics make to its customers?
We promise excellent quality, unquestioned reliability, and superior product value for the cost. We also guarantee the best lead-time in the industry, and we always deliver on schedule. We listen to our customers, and we adjust our actions accordingly.