Factory & Manurfacturing

DALI

DALI stands for Digitally Addressable Lighting Interface. DALI is a recognised standard employed by all ballast manufacturers that offer DALI ballasts. This system assigns an individual address to each luminaire i.e. 001, 002, 003, allowing control of each individual luminaire. All luminaires can be controlled from a central desktop PC, and can be manually over-ridden at a wall switch, or can be used in conjunction with a daylight or occupancy sensor. DALI can offer two-way communication between the luminaire and the PC which provides valuable information and reports such as operating status of individual luminaires.

DSI

DSI is Digital Series Interface and is a more controllable version of digital dimming. This enables the user to group luminaires, operate daylight linked dimming and other controllable options. DSI is a Tridonic name and can be set up with a variety of control options and controllers, some offered by other manufacturers designed purely to work with the DSI ballast. DSI ensures that there are no issues with interference from the switching and the dimming of the luminaire which can affect switch on. DSI is wired using a dimming pair, run around to each luminaire in the circuit.

ANALOGUE DIMMING

Analogue dimming is known as 1-10v dimming. This is because the ballast produces a 1-10v DC supply that can be increased or decreased by a potentiometer, which can be either rotary or slider control. This DC supply can be increased or decreased by the switch to affect the resistance and the amount that the lamp is dimmed. Analogue dimming requires a ‘dimming pair’ of cables to be run around to each luminaire in the circuit

MAINS TRIAC 

TRIAC circuits are widely used, and very common in AC power control applications. These circuits have the ability to switch high voltages, as well as very high levels of current in the two parts of an AC waveform. They are semiconductor devices, similar to a diode.

TRIAC is often used as a means of light dimming in domestic lighting applications, and can even serve as a power control in motors.

PIR VS MICROWAVE SENSORS

Lighting can now incorporate sensors to make them even more effective. Motion detectors can now be used to pick up when someone approaches so the lights are triggered when they are needed. This can be used to save on energy bills by dimming or turning off the lights when no one is around, or it can be used as a security measure, with lights coming on to let you know when someone approaches.

There are two main types of motion detection sensors available, microwave and PIR (Passive Infrared).

PIR

These sensors detect heat. They do this by measuring the ambient temperature of the room using several detection beams. When a difference in temperature is detected by one of the beams, the sensor is activated, switching on the lights. When all the beams sense the same temperature again, the lights will switch off.

MICROWAVE

These motion detectors emit microwave signals and measure the time taken for the signal to be reflected back to the sensor, this is known as the echo time. The echo time is used to calculate the distances from all the stationary objects in the detection zone, to establish a baseline to work from. A person moving into the detection zone causes a disruption in the microwave beam, changing the echo time and triggering the lights.

A COMPARISON

When choosing the best sensor for your application, there are many aspects to take into account;

Because PIR uses the difference in heat to detect movement, ambient temperatures can greatly affect sensitivity. This limitation should be considered if you are looking at motion detection systems for outdoor lighting. The more extreme temperatures of outdoors can have a significant impact on devices’ effectiveness. On the other hand, microwave sensors may struggle more with smaller indoor spaces. Because they are able to detect movement through walls, they can be overly sensitive and be triggered by movement you might not want it to be. There are however solutions to both drawbacks of PIR and microwave sensors.