Home > Exhibition > Content

LED intelligent lighting from the real smart how far!

Jul 13, 2017

In this paper we will explore some of the automated intelligent lighting solutions in the consumer market, and how to provide the latest Low-power MCU, wireless technology and mesh network standards for interconnected home applications to accelerate market development. In addition, we will explore the elements needed to add intelligent connectivity to LED bulbs, including a comparison of key wireless technologies, as well as the industry-initiated wireless Gecko Multi-Protocol Wireless SOC Solution for Silicon Labs (also known as "core Science").

Why smart lighting hasn't crossed the divide

From incandescent bulbs to fluorescent lights to LEDs, common bulbs have undergone 140 of years of development, and LEDs may be one of the most important advancements. More specifically, the intelligent led to develop the Edison never imagined the use of light bulbs.

But the interconnection lighting has been around for a long time, so why hasn't it been as big a success as other consumer-oriented technologies in the Internet age?

1. Intelligent lighting installation is not easy, the cost

120W Energy Saving Outdoor LED Street Light.jpg

One entry barrier is the amount of work required to install the interconnected lighting. This job is definitely not a simple one. The user needs to change the switch, which means to cut off the power of the switch, remove the switch, and replace it with a new switch. This level of home improvement programs is beyond the reach of most homeowners. Another factor that binds the development of the market is the cost. As with anything, the adoption rate will increase as long as the consumer-oriented price is reduced. New switches, wiring and the installation of hardware circuit of artificial costs is not cheap, even if the LED is very popular, the cost is still a major obstacle. But now, things have changed.

In 2014, a standard LED bulbs were priced at $25, and today prices are only about $2. A typical American family has 40 lampholders, and imagine that the cost of buying a lightbulb has fallen by nearly US $1,000. In addition, benefits from multi-protocol flexibility and ease of use provide a better user experience and enhanced usage case. You can simply deploy the network with Bluetooth to the ZigBee device, or you can run ZigBee or thread and Bluetooth at the same time.

In addition to cost, LED bulbs are really hands-on solutions. Simply rotate the bulb into the existing lamp holder and connect it immediately through the smartphone. The ubiquitous connection is also a big advantage of LED. Almost all smartphone users know how to use connections. As a result, only LEDs have overcome two major hurdles: easy to install and easy to use.

2. Wireless protocol standards are mixed, multi-protocol design is looking forward to rescue

Another obstacle that we have mentioned, the different standards of agreement, can be solved. Today, most interconnected bulbs use ZigBee or Low-power bluetooth. The interconnect switch can use private protocols as well as ZigBee. Multi-protocols have become increasingly important because, while each standard has its own advantages and disadvantages, the manufacturer is not interested in risking the risk of being eliminated by betting on an agreement. Therefore, if the solution allows developers to flexibly decide which protocols are best suited to their application, the solution will open the market in a way that is not yet present. Another factor in choosing a single wireless protocol is regional preference.

ZigBee, for example, has a strong influence in the United States, but not in Asia. As a result, vendors may be forced to build a product version of ZigBee in North America and build another version of the product that uses a Low-power Bluetooth in Asia. At this point, you need to silicon labs suppliers to help.

Both now and in the future, new EFR32 wireless gecko can simplify connectivity. The new wireless gecko has more memory, provides features such as wireless software updates, and supports applications for enhanced and evolving site protocol requirements.

For example, if a customer buys a luminaire that uses only ZigBee, you need to make sure that the luminaire is connected to an existing ZigBee network or gateway. However, with multi-protocol support, end users do not necessarily know what type of network they are connected to.

If the supplier supports both ZigBee and Bluetooth, the situation will change. The device defaults to Bluetooth and is controlled through smartphone applications. The application can then search for other networks and join if the ZigBee network is recognized. The device will then be configured or booted for use as a ZigBee device. The end user does not need to know what is going on, except to use the application, no longer having to worry about anything else.

Similarly, adding gateways can extend the network beyond the local network. By connecting the lighting network to the router, the device can be controlled and monitored when the user is not at home.

When all this happens, the user is not even aware of all connection events that occur in the background. It works silently.

Now, the flexibility and ease of use of multi-protocol compatibility has become a competitive advantage,

Provides a better user experience and enhanced use case.

Make ordinary LED bulb intelligent

LED bulbs have evolved over several generations and now have better color balance, stronger reliability and lower costs. Many led bulb manufacturers are looking at how to create more innovative intelligent interconnected bulbs. To add intelligent wireless connectivity to LED bulbs, some design challenges need to be overcome. RF modules for ZigBee and Bluetooth Smart are easy to get. From a high-level point of view, simply adding the RF module to the existing design seems very simple.

Electronic ballasts in LED bulbs usually contain pmic and some high voltage discrete components. The electronic ballast usually drives the LED bulb in constant current to achieve constant brightness and does not vary with input voltage or temperature. The electronic component also provides a good power factor and can be used with conventional wall dimmer.

Pmic usually includes an auxiliary power supply for the pmic itself. Pmic Auxiliary power supply can also be used for MCU, Wireless SOC or RF module power supply. The auxiliary power supply is typically an unstable 10 to 15V power supply. Therefore, a linear regulator is required to reduce this voltage to provide a stable 3V or 1. 8V power supply.

The second challenge is how to turn off the LEDs or dimming the LEDs. One method is to add a MOSFET between the cathode and the ground of the LED so that the MCU is used for switch control. If Pmic was originally designed for a constant load, this method poses some problems. Disabling pmic also disables auxiliary power and is therefore not available.

1498178137091087781. png

Circuitry needed to add intelligent connectivity to LED bulbs

Previous generations of intelligent interconnect LED bulbs utilize modified basic LED bulb designs. The next generation of smart LED bulbs combine ballast electronics with pmic designed specifically for smart bulbs. These designs include a stable low-voltage power supply that is always enabled and can control the brightness of LEDs without additional MOSFET.

Energy-saving standards such as the EPA Energy STAR program and the California Energy Commission (CEC) title 20 electrical efficiency plan are strictly required for standby current or absorbed current. Energy STAR Bulb Specification 2. The 0 version stipulates that the standby power must be lower than the per MW. CEC's title 20 is more stringent, stipulating that in standby mode, the power must be lower than the MW. Although Wireless transceiver power is far below this limit, it is still a challenge to convert AC line voltage to RF transceiver voltage. Auxiliary power supply needs to be more than 50% efficiency and less than 100mW of static current consumption for the RF module to provide approximately MW power.

The RF module and antenna layout presents some physical design challenges. The Ballast circuit board of the basic LED bulb usually has a metal barrier around it to minimize the EMI of the switching power supply. Intelligent LED bulb design needs shielding ballast, and RF to provide a good antenna. If the RF module is positioned vertically near the top of the bulb, the simple PCB antenna on the module may work. However, this may interfere with the light conduction and make the smart semiconductor near the LED heat source. The designer needs to carefully consider the impact of RF performance on bulb availability. Reliable connectivity is important for consumers.

Last but not least, the temperature environment of the RF module is also a consideration. Ideally, RF modules should be far away from the heat of the LED and ballast electronic components. However, the idea is sometimes impractical. The reliability of LEDs and wireless SOC can be improved by monitoring the temperature of LEDs and wireless SOC and dimming LEDs to limit heat. The thermistor installed near the LED can monitor the LED temperature, while the wireless Soc may have a chip temperature sensor.

Wireless update and common boot loader

Finally, the existing equipment that adapts to the future needs is one of the main advantages of wireless function. Transferring a new image file to a wireless device without requiring external storage means that the vendor can bring new functionality to the existing device.

As we discussed earlier, it is not uncommon for a family to have 40 light bulbs. Manually replacing each bulb will be cumbersome when the latest Bluetooth standard is released, but you don't have to worry about it now.

You are no longer limited to updating to the latest version of ZigBee or Bluetooth by using a common boot loader that applies to all wireless standards. You will be able to switch back and forth between ZigBee and Bluetooth as needed.

 Best selling products:90W Power Saving 120lm/W LED street light,150W Die-Casting Aluminum Outdoor High Power LED Street Light,120W Energy Saving Outdoor LED Street Light,60W 120lm/W Highbright Slim LED Street Light