Smart Lighting & Dimming Technologies

01 / Technology

Phase Cut Dimming

Phase-cut dimming controls light output by changing how much of each AC mains half-cycle is delivered to the lighting load.

How it works

The AC supply is a repeating sine wave. A phase-cut dimmer turns the load on or off at a chosen point in each half-cycle, which reduces the average power available to the luminaire.

Leading-edge, or forward-phase, dimming delays turn-on after the zero crossing and then conducts for the remainder of the half-cycle. It has long been associated with simple TRIAC-style wall dimmers.

Trailing-edge, or reverse-phase, dimming conducts from the start of the half-cycle and turns off before the next zero crossing. This method is often used with electronic lighting loads because the switching edge can be shaped more gently.

General benefits

• Uses the existing mains conductors between a dimmer and the load, so additional control wiring is not required.
• Is widely understood in retrofit work where a wall dimmer already exists.
• Can cover a useful brightness range when the dimmer and the load electronics are selected to work on the same phase-cut method.

Typical applications

• Residential rooms with wall dimmers
• Hospitality guest spaces
• Retail and restaurant retrofit lighting
• Downlight and decorative circuits on mains dimmers

02 / Technology

DALI Lighting Control

DALI, the Digital Addressable Lighting Interface, is a two-way digital bus used to command and query lighting devices over a dedicated control pair.

How it works

Devices share a common digital line. Commands can be sent to a single address, to a group, or as a broadcast to every device on that line.

Addressing lets each control gear or input device be identified separately. Installers can then change which luminaires respond together without rewiring the power circuit.

Groups collect devices that should move together. Scenes store target levels so a space can recall a prepared lighting state with one command.

Because the bus is bidirectional, a controller can ask a device for its current level or status instead of assuming that a command was received.

General benefits

• Individual luminaires can be adjusted without dedicating a separate power circuit to each one.
• Grouping and scene recall support day-to-day operation of offices, meeting rooms and architectural spaces.
• Status feedback helps commissioning and later maintenance.

Typical applications

• Commercial offices and meeting rooms
• Architectural façades and feature lighting
• Education and civic buildings
• Campus or multi-zone lighting systems

DALI DT6, DALI DT8 and DALI-2

DT6 is commonly used for single-channel brightness. DT8 is commonly used for colour-control functions such as tunable white. DALI-2 is a certification programme. This page explains those terms. It does not list a JSK URJA DALI product and does not claim DALI-2 certification.

A DALI-compatible LED driver is designed to work with a compatible DALI system. That is not the same as DALI-2 certification, and JSK URJA does not use the DALI-2 logo.

Read the DALI-compatible LED drivers page for the India manufacturer enquiry path, or compare tunable white and phase-cut control.

03 / Technology

Tunable White & CCT Control

Tunable-white systems change both intensity and correlated colour temperature, moving light between warmer and cooler white appearance.

How it works

Correlated colour temperature, or CCT, describes how warm or cool a white light appears. It is expressed in kelvin. Lower values look warmer; higher values look cooler or more like daylight.

A common method mixes a warm-white LED channel with a cool-white channel. Changing the ratio shifts CCT; changing the combined output shifts brightness.

Some digital control systems treat intensity and colour temperature as separate axes, so a space can hold one CCT while dimming, or change appearance at a fixed level.

General benefits

• Lighting appearance can follow the use of a room: warmer for rest and hospitality, cooler for task-oriented work.
• One luminaire family can serve several visual moods without changing lamps.
• Designers can align lighting with time of day or programmed scenes while remaining within the white-light range.

Typical applications

• Hotels, restaurants and guest circulation
• Offices and meeting rooms
• Residential living and wellness spaces
• Galleries and feature interiors

04 / Technology

Smart Lighting & Automation

Smart lighting treats luminaires as part of a wider control system that can respond to people, time, sensors and building or home automation.

How it works

A lighting system may combine drivers or controllers, occupancy or daylight sensors, user interfaces and a supervisor such as a gateway or automation processor.

Control can be local, such as a scene plate in a room, or supervisory, such as a schedule or a building system that sends set-points to many zones.

Wired digital buses and wireless networks are both used to carry commands. The chosen method depends on the building, the retrofit constraints and the required integration.

Automation logic typically includes occupancy, time schedules, daylight response and recalled scenes. Lighting then becomes one service among others in the same project.

General benefits

• Spaces can reduce unused lighting when they are empty or already daylit.
• Central supervision simplifies operation of larger sites.
• The same hardware can serve manual override and automatic behaviour.

Typical applications

• Homes and apartments with scene or app control
• Hotels and serviced residences
• Commercial floors and common areas
• Building-management and campus projects