SummaryRecently the designers found a approach to improve speed,cost and linearity of A-D conversion--Using  ‘voltage-to-frequency converters’(VFCs) to perform A-D conversions in data acquisition systems that require strict monotonic response,high resolution and reuced noise and moderate speed.The VFC produces a pluse train with frequency proportional to the input voltage.Then a microcontroller or logic converts fre quency into a number by opening a gate for a fixed amount of time and counting how many.However,this approach is not perfect.the main drawback is that to increase speed, designers have to run the VFC at high frequency, which deteriorates linearity.   Design Ideathe design idea of this aproach reverses things.A circuit converts input voltage into a proportional time interval;then,the micro uses that interval to count pulses coming from its internal clock.The results are impressive:1.Good linearity as the voltage-to-period converter runs at low frequency2.Faster A-to-D conversion due to the high value of the clock frequency3.Potentially simpler program or logic, as it only has to count clock pulses, gated by the circuit4.Low priceCircuit and Voltage IssueThe key is that increasing the count frequency does not affect linearity of the A-to-D conversion, while increasing the frequency of the VFC always means worse linearity.Just see the following picture: This picture is a circuit about modified VFC,where the input voltage VIN and the reference voltage VREF swap their roles. The R1-R2 network shifts the input voltage so it is always more positive than the reference voltage and maintain proper operating conditions. The circuit uses all switches of the 4066 part: two in parallel build S1 to reduce the effect of imperfect switch flatness on linearity, one switch goes for S2, and the last switch is part of the start-up circuit, paralleling CINT, and controlled by the logic during initialization.As the input voltage changes from 0 to 5V, the output period changes from 78 to 578µs. Integration capacitor CINT and the threshold level of the one-shot’s Schmitt input do not participate in the period vs voltage relation.Filling the period with 10MHz clock pulses generates numbers from 780 to 5780 – one count per millivolt. Linearity is one count or ±0.02%, which is not a surprise when the maximum frequency is only 12.8kHz. The maximum time of the A-to-D conversion is 578µs. This is 8.65 times faster compared to the case of a 1MHz VFC, where it would take 5,000µs to count 5,000 pulses of 1µs. The interface program is short and simple.Calibration involves some back and forth due to the shift of the input voltage: adjust sensitivity to 100µs/V using the trim-pot of the one-shot. The nominal duration of the one-shot pulse is 26µs. Cancel the 780 count offset in the controller.The following table  shows that the V-to-P approach is significantly better than the V-to-F one (Refs 3, 4). Surprisingly, no chip-maker offers this type of converter.

SummaryIf you have follow the informations of sensor,you will know that sensors are always in a state of rapid progress.Now I will state a few things to prove it in the following.Sensor,also called Transducer, is a kind of detection device,it can receive the measured information and then output them according to a certain rule or other needed form to meet the transport, handling,storage,recording,displaying and controlling of imformation,etc. Know more about it,you can read the article : Most Comprehensive Sicence Popularizing of Sensor (detection device) Researchers created quantum control technique for quantum sensorsAs we all known,there is a common problem that designers are harder to deal with quantum sensing devices. How,University of Sydney researchers have sloved this trouble associated with this super-sensitive tech. They have created quantum control techniques in collaboration with Johns Hopkins Applied Physics Laboratory and Dartmouth College. This development will allow next-gen ultra-sensitive sensors to identify small signals and reject unwanted background noise.By applying the right quantum controls to a qubit-based sensor,the team adjust its response in a way  that guarantees the best possible exclusion of the background clutter—that is, the other voices in the room. In order to obtain and analyze signals, measurement protocols are set in place. Over the years, these protocols have lagged behind the advancement of electronic devices. The disparity has led to a phenomenon known as “spectral leakage,” which occurs when quantum sensors return unclear results.What's more, the new control protocols have reduced spectral leakage by several orders of magnitude by using improved sensor hardware. All the approach is relevant to nearly any quantum sensing application and can also be applied to quantum computing as it provides a way help identify sources of hardware error.‘quantum control techniques' is a major advance in how to operate quantum sensors.  New sensors uses for effective control of enviroment pollutionEnviromental pollution issue are always paid great attention by human being as the development of all the world. A team from the Faculty of Physics of Lomonosov Moscow State University has suggested using porous silicon nanowire arrays in highly sensitive gas sensors which may be used both for effective control of environment pollution levels and for the monitoring of air composition in closed spaces,from classrooms to space stations.According to researchers, these devices will be able to detect the presence of toxic and non-toxic gas molecules in the air at room temperature.Each sensor consists of an array of 10 micron long organized silicon nanowires with diameters ranging from 100 to 200 nm. Each nanowire has porous crystalline structure. The size of silicon crystals and pores between them in individual nanowire, varies from three to five nanometers.ey can be obtained by means of a cheap method of metal-assisted chemical etching. It is based on selective chemical etching, i.e. partial removal of surface layer from a bulk crystalline silicon with the use of metal nanoparticles as a catalyst. Moreover, the procedure is quick—at least 100 elements can be produced in a lab within just one hour.Such porous nanowires have huge specific surface area due to which their physical and chemical properties are extremely sensitive to molecular environment. It was also found out that the obtained samples exhibited an effective photoluminescence in the red spectrum region at room temperature. What's important,this gas sensors based on porous nanowires both work at home temperatures and also are reusable, because the all observed effects were completely reversible. Military sensor systems collect accurate informationCollecting accurate user and environmental information such as enemy's location,survive shock, vibration, moisture plays an important role in military system. Deployment complaints about the platform aside, Lockheed Martin’s Electro-Optical Targeting System (EOTS) for the F-35 Lightning II is a high-performance, lightweight, multi-function sensing solution for precision air-to-air and air-to-surface targeting (Figure 4). Integrated into the aircraft fuselage with a rugged sapphire viewport, the device talks to the aircraft via a fiber-optic interface.Presented as the first sensor to combine forward-looking and infrared search along with track functionality, EOTS enables situational awareness and precision delivery of laser and GPS-guided weapons. Advanced EOTS, the next iteration, will incorporate enhancements and upgrades like short-wave infrared, high-definition television, and an infrared marker.Today’s military sensors must operate well on their own, and function as part of a combined-arms approach with an interlaced network of sensing, to detect threats of any nature from any direction. One such way to address this is with a battlefield awareness solution like 3D Advanced Warning System (3DAWS) from BAE Systems, which can provide universal threat detection to an aircrew with a layered countermeasure defense.The modular and expandable system can integrate with fixed- and rotary-wing aircraft and countermeasure systems, with the flexibility to work with existing radar or laser warning systems. The core of the 3DAWS suite is the passively-cued, semi-active radio frequency 3D Tracker element, which serves as an adjunct to current and future passive threat detection systems. 

 This article is a brief introduction to contactor.  Catalog  I. What is a Contactor?II. Differences Between Contactor and RelaysIII. Contactor Working PrincipleIV. About Arc SuppressionFAQ I. What is a Contactor? As an essential part of the motor control gear, the most widespread switching device used in a starter is the a,c. airbrake contactor which consists of contact assemblies actuated by electromagnetic action. An operating coil is enclosed by the magnetic yoke, as well as when energized attracts an armature to which is attached a set of moving contacts which make with a set of stationary contacts. Modern contractors use a silver alloy contact tip, normally silver–cadmium oxide or silver–tin oxide alloy attached to a brass or copper backing strip. The choice of tip material is critical and is normally established after many types of tests.  Note: The rating of the contactor depends on the size, shape, and material of the contacts and on the efficiency of the arc extinction method used. An electrical contactor is an electromagnetic switch similar to a relay. It is a switch that can be controlled with the current/pulse to switch over an electrically powered circuit. II. Differences Between Contactor and Relays Let me put forward a basic question firstly:If you see in industrial control panels, both relays and contractors are used for the same purpose, so why different names? Both of them perform the same task. The relay is usually used in low voltage paths such as switching tube-light or small LEDs. The contactor is used in electrical circuits of industrial motors or other heavy applications. So, the difference is from an application point of view. The basic working principle is the same for both. The relay behaves similarly to how a contractor works. If you want to switch circuits with high voltages, use contactors and if you want to switch light voltages then the relay is ready for you.  It is important to note here the difference between protection and switching. A relay is a protection device whereas a contactor cannot assure you about protection. The relay can differentiate between normal & abnormal conditions and give command accordingly which contactor cannot. Switching means to break and make a circuit and a contactor is mainly used for that purpose. III. Contactor Working Principle When the contactor coil is de-energized, gravity or a spring returns the electromagnet core to its initial position and opens the contacts. For contactors energized with alternating current, a small part of the core is surrounded by a shading coil, which slightly delays the magnetic flux in the core. The following video will help you understand the working principle of contactor more intuitively:  IV. About Arc Suppression Most motor control contactors at low voltages (600 volts and less) are air brake contactors; air at atmospheric pressure surrounds the contacts and extinguishes the arc when interrupting the circuit. Modern medium-voltage AC motor controllers use vacuum contactors. High voltage AC contactors (greater than 1,000 volts) may use a vacuum or an inert gas around the contacts. High voltage DC contactors (greater than 600V) still rely on air within specially designed arc-chutes to break the arc energy. High-voltage electric locomotives may be isolated from their overhead supply by roof-mounted circuit breakers actuated by compressed air; the same air supply may be used to "blow out" any arc that forms.Without adequate contact protection, the occurrence of electric current arcing causes significant degradation of the contacts, which suffer significant damage. An electrical arc occurs between the two contact points (electrodes) when they transition from a closed to an open (break arc) or from an open to a closed (make arc). The break arc is typically more energetic and thus more destructive. Without adequate contact protection, the occurrence of electric current arcing causes significant degradation of the contacts, which suffer significant damage. An electrical arc occurs between the two contact points (electrodes) when they transition from a closed to an open (break arc) or from an open to a closed (make arc). The break arc is typically more energetic and thus more destructive.FAQ 1. What is the main function of contactor?Function of contactor, generally used for connected and disconnected of electric current supply. Usually in use for applications: motors, heater, lighting or electric power distribution. 2. Why do we need contactors?Contactors are used for high power applications. They allow a lower voltage and current to switch a much higher power circuit, so they are generally larger and more heavy-duty than control relays, enabling them to switch higher power loads on and off for many thousands of cycles. 3. How a contactor is wired?Break your circuit, L N E through your contactor. Link a permanent live and a neutral from your supply to your coil (Al + A2) then use your switch feed to your photocell from A1, and switch the wire to the switched phase of your contactor load. This should now open when light, close when dark. 4. What is NO and NC In Contactor?Normally Open (NO) and Normally Closed (NC) terms refer to type of dry contact or wet contact. Put very simply, a Normally Open sensor will have no current when in a normal state but when it enters an alarm state it will have +5V applied to the circuit. 5. How many types of contactors are there?The contacts are classified as power contact, auxiliary contact, and contact spring. There are two types of power contact; stationary contact and movable contact. The material used for the contacts has stable arc resistance and high welding resistance. 6. Why contactor is used?Contactors are used for high power applications. They allow a lower voltage and current to switch a much higher power circuit, so they are generally larger and more heavy-duty than control relays, enabling them to switch higher power loads on and off for many thousands of cycles 7. What is the difference between a relay and a contactor?A contactor joins 2 poles together, without a common circuit between them, while a relay has a common contact that connects to a neutral position. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V. 8. What are the types of contactors?There are different types of contacts in a contactor, and they are; auxiliary contact, power contact, and contact spring. The power contact has two types that are; stationary and movable contact. Material for making contacts must have a high welding resistance and stable arc resistance. 9. What are the three major parts of a contactor or relay?There are three major parts of a contactor or relay: the coil, mechanical linkage and contacts. The coil is used to create a magnetic field and is rated based on voltage (24 V, 120 V, 208/204 V, 480 V). The mechanical linkage connects the armature to the contacts when the coil is energized, completing the circuit. 10. How contactor is connected?A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagnet controlling a 230-volt motor switch. Unlike general-purpose relays, contactors are designed to be directly connected to high-current load devices. 

Summary Energy-efficient sensor nodes are crucial to the development of the industrial internet of things (IIoT).Engineering team are trying to optimise energy efficient IIoT sensor nodes.In many cases, these devices will have to perform for years on a single battery charge. That calls for an implementation that is as energy efficient as possible. Achieving this demands a holistic approach to energy optimisation, one that reaches from the system level down to process and circuit-design choices.     Problem met Engineering team are trying to optimise the energy comsumption of an IIOT sensor node is that many of the design decisions interact with each other. And there are often hidden complexities of designs that lead to energy consumption being much higher than expected. For example, conventional wisdom points to the power consumption of an RF transmitter being a major influence on total energy. But, even though the receiver element may consume far less instantaneous power, system-level decisions that call for the device to listen for intermittent updates from a server can lead to it being left active for long periods of time – tens of seconds per hour versus tens of milliseconds for the transmitter. Because of the long operational life of a typical IoT sensor node, the energy used even when subsystems are sleeping can be responsible for a heavy drain on the battery.   Integration Despite the complex interaction between application design and implementation, there are some high-level choices that are likely to lead toward an optimal solution. One of these is the use of integration. Although it is entirely possible to use 2D-IC and 3D-IC multi chip packaging to assemble a compact IIoT sensor node from off-the-shelf components, integration into a single custom integrated circuit (IC) provides not just significant benefits in terms of cost and size but reductions in power consumption. In order to communicate with off-chip memories and analogue and RF on traditional PCB-based implementations, Input/Output (I/O) drivers with significant current draw are often required. A single system-on-chip (SoC) makes it possible to remove such power-hungry circuits.     The duty cycle and lifetime energy consumption The other fundamental consideration for designing energy-efficient IIoT sensor nodes is an understanding of the duty cycle and its impact on lifetime energy consumption. Simply minimising the power consumption of individual elements is not enough to guarantee that a remote or  inaccessible sensor can operate on a single battery charge for a decade or more. In such a situation, every microjoule the node requires from its battery is important. But that does not mean the system powered by a typical battery can consume no more than a few microwatts at any point in its life. Such a system would not be able to take measurements and communicate them wirelessly in any practical way. The use of duty-cycle planning makes it possible for the system to perform tasks that take significant amounts of power for short periods, trading those bursts against savings that can be made while much of the system is quiescent. For example, the RF subsystem of a wireless sensor node need only be powered when it is active. This is likely to be one of the most power-hungry parts of the overall design because of the need to supply enough transmitter power to ensure packets of data can be delivered reliably. However, the power consumed by the transmitter portion of the RF subsystem is relatively easy to control. Once a packet has been delivered the transmitter can be shut down. But there can still be significant power drawn by subsystems such as the RF receiver that continue to remain active once the transmitter has finished sending.   The RF receiver often needs to remain active because of timing uncertainty and this type of uncertainty has a major influence on overall energy consumption. Whereas the transmitter has predictable requirements – it need only be activated when data is ready to send – the receiver needs to be active for much longer. It needs to wait for acknowledgments from nodes to which it is sending data, and also needs to activate periodically to be able to listen for unsolicited messages. As a result, the overall energy consumption of the RF receiver will often exceed that of the transmitter over the lifetime of the sensor, even though its instantaneous power demand is lower. An efficient design will exploit power-saving techniques such as putting much of the circuitry into a low-activity state until an RF signal is detected. Another optimisation is to reduce the amount of time per minute the receiver is active at the cost of the sensor node’s responsiveness to external commands.     Although they might appear to be essential to all operations, the microprocessor core and its memory subsystem need careful duty-cycle management because they can demand very high levels of power. The problem for many designs is that software running on the processor is often responsible for core tasks such as fetching data from sensors and passing messages to the RF subsystem. This appears to mandate that the processor be fully active whenever sensor inputs need processing.   However, in many cases, the work performed by the software is very simple. It is quickly checking data values to see if they have passed a limit that might signal a problem, or for increased activity that needs closer inspection. Activating the processor to handle all the data is wasteful and can easily be offloaded to custom hardware or a programmable state machine. These circuits consume far less power and can run independently of the processor, so that and the memory array can be powered down.   Current leakage Even when most of the device is powered down, the power drawn during lengthy periods of sleep can be surprising. Energy lost through current leakage in subsystems that need to remain powered can incur a heavy overhead when analysed over the lifetime of the system because the time the system spends sleeping can be orders of magnitude longer than that during which the system is active. The problem of leakage calls for design techniques that limit leakage in subsystems such as real-time clocks and interrupt controllers to the nanoamp level. It might seem reasonable to disable interrupts for external events and only keep the real-time clock running in some applications. However, in that design the system needs to wake at regular intervals to check inputs that may incur unwanted energy consumption if there is no overall change to record. If the long-term energy usage of an interrupt controller is low enough, keeping that active to respond to events as they happen may make more sense.   When the processor and memory subsystem are powered down, a key decision is how to manage temporary data. One option is to use specialised retention register and memory cells, at the cost of some leakage power. Another is to put important data, such as calibration values, into non-volatile memory (NVM). This allows values to be restored quickly on restart but allows the leakage-prone SRAM arrays and registers to be powered down fully until then. But NVM choices are not always straightforward.   Processes that are optimised for low leakage and that support high-density NVM options may not have the performance required to support efficient RF modules on-chip. The energy needed for I/O drivers that transfer data to an off-chip RF transceiver may outweigh the power savings and security advantages obtained from implementing NVM on-chip. Careful analysis of the application’s requirements will indicate which choice is better for the custom SoC solution.   For the portions of the design that will be active for much of the device’s lifetime, careful attention to detail is required. Seemingly small details such as choosing to multiplex inputs into an analogue-to-digital converter (ADC) will help determine the architecture of choice for those circuits. A sigma-delta ADC may initially appear to offer a good trade-off between accuracy, energy efficiency and silicon area. But it is not suited to multiplexing. Often a successive approximation (SAR) architecture offers superior performance for industrial sensor signals. Advances in SAR design have pushed the energy per bit per conversion down into the range of tens of femtojoules.   Front-end analogue circuits are just as important as the ADC. Amplifiers and buffers that isolate and condition signals before conversion can consume high levels of power and they will be active for long periods of time. Analysis of the specific requirements for bandwidth and accuracy often allow for optimizations that reduce the energy of front-end circuitry and ADCs.   To tie all the subsystems together into a working custom SoC demands the use of power-aware design methodologies to ensure subsystems and circuits are activated properly when required, and can be powered down without disrupting the operation of other parts of the custom IC that need to stay running. Standards such as the Unified Power Format (UPF) have been designed to support such power-aware methodologies, but their application requires experience and attention to detail at different levels of abstraction.   Take an example For example, there may be a logical connection between two subsystems that demands they be active at the same time. But physical restrictions may call for them to form part of a larger power island – an area of the mixed-signal ASIC with a common set of power and ground rails – that includes other subsystems that are not required during that time. Design verification needs to ensure that the entire island is powered up correctly. If not, the final SoC will fail. Such physical design considerations may call for changes to the power-control architecture if the consumption of the whole island is higher than the budget allows. It may call for subsystems to be assigned to different power islands, for example.   Verification also needs to pay attention to on-chip noise, which may point to further optimization of the power-island strategy. For example, a low-noise LDO may be used to power sensitive mixed-signal sections that operate autonomously. Once measurements have been taken or RF communications have been completed, a higher-efficiency DC/DC converter may then be reactivated to analyse incoming data and make decisions.   Although the core requirements of energy efficiency in IIoT sensor nodes are readily understood, as can be seen, the implementation choices are complex and often subtle. Many factors affect the optimum solution for a given IIoT sensor node application, although a custom SoC will frequently be the best target in terms of energy and overall cost. Therefore, the ability to call on the expertise of design teams with extensive experience in custom mixed-signal IC implementation is key to success.  

SummaryA digital temperature sensor IC which offers accurate measurements in the temperature range -20 to 10°C has been introduced by ams. The performance of the AS6200C makes it easier for designers of refrigerators and data loggers in cold-chain storage equipment to meet demanding targets for system-level accuracy. The AS6200C’s measurements are accurate to ±0.2°C between -20°C and 10°C, the temperature range over which storage equipment for perishable goods operates.  AS6200C Sensor ICAS6200C sensor's accuracy is guaranteed over the device's supply voltage range of 1.8~3.6V. In temperature control and temperature logging applications, the total error budget is made up of multiple components. By minimising the error at the point of measurement, the designer gains extra headroom for other error and noise sources, such as the heat generated by board-mounted com-ponents. The use of the highly accurate AS6200C gives the designer more flexibility to modify other elements of the system design while keeping total error below a specified maximum level. The AS6200C integrates a sensor front end, 12-bit analogue-to-digital converter and digital logic in a small WL-CSP package. It provides a digital output over an I2C interface to any host microcontrol-ler. The device performs on-board digital signal processing, which means that it needs no user calibration, and its linearised output requires no compensation by an external microcontroller. The AS6200C is intended for use in equipment for storing and transporting food, pharmaceuticals, flowers and other perishable goods, as well as in domestic and commercial refrigerators. It is well suited to data loggers that comply with the EN12830:1999 class 1 standard.The new device extends the ams family of small, accurate digital temperature sensor ICs, joining the AS6200 sensor, which achieves peak accuracy between 0 and 65°C. “The AS6200C offers the market a unique combination of small size - its footprint is only 1.5mm2 - very high accuracy over the cold-chain monitoring and storage temperature range, and a convenient digital output requiring no calibration or linearisation. It provides a new example of the value of the low noise, high sensitivity, high linearity semiconductor technology underlying the outstanding performance of ams' sensor solution products,” said Nikolai Haslebner, Marketing Manager at ams. 

SummaryChristmas is coming,as well as the New Year's Day. In keeping with the festive lighting of the holiday season,there are various LED lighting architecture in the world. Now let me take you to tour the landmarks lit with LEDs.  In the touring of this LED architecture, I will also introduce how this landmarks be done. Well,these These attention grabbing displays are dependent on products that can deliver a wide range of colors, and a control scheme that allows lighting designers to fully realize their creative ideas. First Stationlet's begin with the glorious Miami in Miami,Florida.  Located downtown, the Miami Tower is a 47-story landmark that you may have seen in films and on television. Before conversion to LEDs, it was lit with a total of 382 1,000 W and 400 W metal halide fixtures, with gels (color filters) applied by maintenance crews to change the color effects. Conversion to a combination of LED flood lighting and strip lighting reduced energy, maintenance, and operating costs by over a quarter million dollars annually, and the building fa?ade can now be changed to a virtually limitless combination of colors and patterns with the “push of a button”. Miami Tower and the other landmarks reviewed in this article are illuminated using Philips Color Kinetics products, which currently have a bit of a monopoly in architectural installations. The control scheme uses a data enabler to combine power with a proprietary Ethernet DMX-based data signal called KiNET, prior to routing to luminaires, junction boxes, and/or strings of strip lights.Over 16 million color combinations can be achieved through the 8-bit channels of Red/Green/Blue/White or Red/Green/Blue/Amber luminaires. A number of different controllers can be used to program either static or dynamic displays. DSP techniques ensure that data corruption is negligible even in noisy, high-EMI environments, e.g., adjacent to powered radio antennas.  Second StationLet's travel across the country to the San Francisco-Oakland Bay Bridge.  The Bay Lights of the San Francisco-Oakland Bay Bridge, installed in 2013 in what was meant to be a two-year run to celebrate the bridge’s 75th anniversary, is currently the largest LED lighting sculpture in the world. With over 25,000 white LED nodes installed on the 1.8 mile western span, the bridge surpasses even the Eiffel Tower in number of LEDs.This lighting system uses light strands,each made up of 50 individually controllable nodes designed to operate in the demanding environment conditons of the bridge--rain,vibration,wind and even road debris. Control software scans the installation to ensure that all lighting is operational Bridge lighting projects are the most challenging to implement according to Philips, because the process can include not just lighting designers, architects, and contractors, but also transportation authorities and the Coast Guard, each with separate concerns and requirements. In addition, lighting installation usually requires workers to hang from suspended cables, and to work at night to minimize traffic impact. Doesn't that sound like fun?  Third StationThis is the season to be shopping,so let's envy the lucky folks in Philadelphia who get to spend time at the appropriately named Lit Brothers Building.  Listed on the National Registry of Historic Places in 1979, the Lit Brothers Building takes up a full city block with its mix of retail and office space. Unlike newer installations, preservation of the historic and structural aspects of the building were paramount in the lighting design, which includes both flood lights and light strips to illuminate the fa-ade and ornamental columns.As engineers, we’re interested in the technical and practical details of these LED projects, like lower operating costs and reduced maintenance requirements, but the non-energy benefits these projects bring can be even more significant. They play a tremendous role in creating a space that local residents and tourists look forward to visiting, enhancing the sense of fun and excitement in the community and the economic boost that often goes with it. Fina Station   The Bai Chay Bridge stands 50 m (164 ft) over Ha Long Bay, one of the most popular and beautiful tourist sites in Vietnam. In 2000, Ha Long Bay was nominated as one of the new seven natural wonders of the world, and in 2004, Ha Long Bay hosted almost 3 million tourists due to its geological value and natural beauty. Scattered across this bay are 1,969 islands, beautiful emerald waters, and with the Bai Chay Bridge, an edition in 2006, a new landmark in Vietnam.The Bai Chay Bridge has the widest width of any cable-stayed, single-plane concrete bridge in the world. The bridge was built to improve traffic conditions and adopt Japanese construction technologies. To make this landmark even more beautiful, the Bai Chay Bridge is now illuminated in colorful LED lights that reflect off the bay waters at night.LED lights were chosen due to their dynamic capabilities, long useful life and energy efficiency. In order to achieve all the goals the investor had set, Philips supplied an environmentally-friendly LED lighting solution for its high efficiency and dynamic and elegant lighting effects.The designers installed ColorReach Powercore gen2 and ColorReach Compact Powercore from Philips Color Kinetics to illuminate the cables and pillars that run high above the bridge, as well as to highlight the dramatic beauty of the bridge’s architecture. ColorGraze MX4 Powercore was used to illuminate the bottom of the bridge, and Archipoint iColor Powercore was used in a direct view application along the spans of the bridge. ConclusionSuch beautiful LED lighting architectures around the world create beauty, enhance entertainment and transform public spaces  for human being and nature. What's more,they witness the LED light's development and become an important milestone in the history of LED lighting.