Lighting Dimmer

Dimmer is a device that is being used to adjust the light brightness. Dimmer works by increasing or decreasing the RMS voltage and hence the mean power to the lamp it is possible to vary the intensity of the output of the light. Variable-voltage devices are used for various purposes; dimmer is generally controlling resistive incandescent, halogen and compact fluorescent (CFL) lighting. To dim fluorescent, mercury vapor and other arc lighting, more specialized pulse-width modulation equipment will be needed for the dimmer.

The size of lighting dimmers varies from small units, used for domestic lighting, to high power units, used in large venue theatre or installation of architectural lighting installations. For the use of domestic lighting, small unit dimmers are generally directly controlled or the use of remote control systems is available. Modern professional dimmers, for architectural lighting or theatre installations, are generally controlled by a digital control system such as DALI or DMX. These protocols are often used in the conjunction with Ethernet.

The dimmer changes in intensity are often called fades in the professional lighting industry. Modern digital dimmer units have more adjustable speed in the control and built from silicon-controlled rectifiers (SCR) instead of potentiometers or other variable resistors because the SCR have higher efficiency. A variable resistor would dissipate the power by heat which has a lower efficiency compare to SCR dimmer, and SCR dimmer does not heat up.

Dimmers were used to be directly controlled through the manual manipulation of large dimmer panels. All of the power had to come through the location of the lighting control, this condition could be inconvenient and potentially more dangerous, especially with systems that had a large number of channels.

Analog remote control system or often called 0-10V lighting control systems became feasible when the thyristor dimmers were introduced. This dimmers were using smaller wire for the control system compared to the heavy power cables of the previous lighting systems. Every of the dimmer had its own control wires, this mean that a large number of wires leaving the location of the lighting control to each of the dimmer. Modern lighting systems are using a digital control protocol like DMX512, or DALI to control a large number of dimmers through a single cable only.

Dimmers can be controlled remotely by using various protocols. An analogue dimmers would usually need a separate wire for each of the dimming channel and carry a voltage between 0 and 10 V. Some of the analogue circuit also derives a control signal and the mains would supply the switches. More wires are needed between the lighting controller and the dimmers when more channels added.

DMX512, one of the digital protocols, have been one of the best choices since the late 80s. Modern dimmer designs are using microprocessors to convert the digital signal directly to a control signal for the switches. This method is giving closer control over the dimmer and giving a diagnostic feedback back to the lighting controller for monitoring.

Fluorescent lamp

Fluorescent lamp is using electricity to excite mercury vapor, fluorescent lamp is also can be defined as a gas-discharge lamp. After the mercury being excited by electricity, its atoms is producing a short wave of an ultraviolet light then cause the phosphor inside the lamp to produce light that is visible. Fluorescent lamp is more efficient than an incandescent lamp being compared by the electrical power conversion. Fluorescent lamp consume lower energy, this typically will offset the higher cost of the fluorescent lamp. Fluorescent lamp is more costly compare to incandescent lamp because fluorescent lamp to regulate the flow of current through the lamp requires ballast.

Fluorescent lamps largely are being mostly used in commercial buildings all over the world. For homes usage, compact fluorescent lamp is being used to save the energy usage. Fluorescent lamps last longer compared to incandescent lamps but the down point of fluorescent lamps are more complex, bulkier, poorer color rendition and contain mercury.

Fluorescent starts up by ionizing the mercury atoms in the fluorescent tube. It does not need much voltage for small fluorescent lamp to strike the arc but for fluorescent lamps that have larger tubes require a substantial voltage, a large amount with the range of thousand volts is needed to strike the arc.

Some fluorescent lamps in the market is using electronic ballasts. Electronic ballasts are using transistors while regulating the current flow in the fluorescent lamp. The electronics ballasts are actually increase the lamp efficiency by converting the incoming power to an output frequency in excess of 20 kHz.

Fluorescent lamp can be found in the market in plenty sizes and shapes. The most popular fluorescent lamp in the market currently is the compact fluorescent lamp. Integrating the auxiliary electronics into the base of the fluorescent lamp, allows the auxiliary electronics to fit into regular light bulb socket which make the fluorescent lamp becomes compact. The usage of fluorescent lamp is mainly in the school and commercial building as fluorescent lamp is more efficient and cost savings. Fluorescent lamps usages are being encouraged replacing incandescent lamps for the energy saving consideration.

Fluorescent lamp cannot use the same dimmer switch as incandescent lamps. Fluorescent lamp dimmer installation requires compatible dimmer ballast. The fluorescent dimmer system using dimming ballast keep the cathodes of the fluorescent tube fully heated even when the current is reduced in the arc. Some compact fluorescent lamps are compatible to work in a lighting dimmer circuit.

School house lighting and commercial building lighting is the most common market for the usage of fluorescent lamp for indoor and outdoor lighting. As an energy saving lamp, fluorescent lamp is one of the leading lamp in the world.