Customer service >Frequently asked questions > Performance & specifications

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 dust-proof, drip-proof, 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 60dB 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 Driver, 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.