Tab Terminals

Panel mount indicators can be attached to the motherboard or power source in a few different ways. One of those ways is by using tab terminals. 

The metal on the tabs transfers the current from the power source to the PMI. Tab terminals are faster to install, delivering production efficiencies for OEMs.

Threaded Housing

A threaded housing is the plastic or metal sheath that goes over the PMI that is ribbed so it can be “threaded” into the panel.

The housing is then secured with mounting hardware such as a lock washer or hex nut to provide additional stability through high-vibration operation.

Through-Hole LED

A through-hole LED is one that is mounted from the panel or the back of the device instead of the printed circuit board and is mounted using two leads.  

Depending on the design of the device, flexible light pipes are best for through-hole LEDs. Through-hole LEDs can also be a great fit for PCBA devices.

Total Internal Reflection

Light pipes must reflect light to carry it around corners. Total internal reflection (TIR) helps light bounce back toward its intended exit point instead of being lost or leaked.

TIR occurs when the angle at which light is reflected when it shines through a surface is greater than a certain limiting angle known as the critical angle.

Translucent

Translucent or semitransparent is a visual characteristic used to describe objects that allow a lot of light to shine through but are not fully see-through.

Transparent

Objects that are transparent, such as a lens or bulb, are completely see-through, allowing light and objects behind them to be clearly visible.

Tri-Color LED

A tri-color LED is a lamp that has the ability to change color three times without requiring additional space on the HMI or panel. 

Typical tri-color LED combinations include: red, yellow, and green. Need a different color combination? VCC can help with a custom PMI design.

UL Listing

UL is a third-party certification company that conducts testing and sets the industry standard for safety for a range of product categories worldwide. 

Depending on the type of device or product, different ratings will be used.

UL Rating

UL is a third-party certification company that conducts testing and sets the industry standard for safety for a range of product categories worldwide. 

Depending on the type of device or product, different ratings will be used. For example:

UL Listed – certification of the entire product vs. its components 

UL-Recognized – for components only – not complete, market-ready products

Different marks are used to indicate UL status by country or region, such as Canada, US and Europe.

UL-Recognized Component

Third-party testing company, UL, can’t certify an entire product based on one aspect of the electronic elements.

Therefore, individual products, like LEDs or PMIs that meet the safety standards are designated UL-recognized components.

Uniform Illumination

A goal of any light pipe’s design, uniform illumination is where the entire indicator surface has even light instead of hot spots in certain areas.

User Experience

User experience (UX) is the outcome users have with a product. Designing for the user experience should work along with designing for the user interface (UI) of the device. 

For an ideal user experience, design for an interface that is useful, usable, desirable, findable, accessible, and credible. Learn more in our UX design guide.