ELE Times December 2016 Electronics News in India | Online Electronics Mag | Page 34

Cover Story

Smart Home Lighting System

Aman Jha, Ranajay Mallik, Raunaque Mujeeb Quaiser and Jitendra Jain
AMG Central lab, STMicroelectronics

In today’s world where energy management and conservation is a
talked subject and smartphones are reshaping our lives, “Smart
Home Lighting System” is one such area which is gaining lot of
attraction in lighting industry. Major advancement in this field is
“Bluetooth Low Energy” for connectivity and remote control.
Bluetooth Low Energy (BLE) is seen as a promising technology for
Smart Home Automation and Lighting. It is upward version of
classic Bluetooth and works in same 2.4 GHz radio frequency
band. One feature that is more prominent in BLE compared with
classic Bluetooth is the reduced power consumption which makes
it suitable for LED lighting segment.
For high efficiency, long lifetime, better light quality and reliability,
LED is already a winner in lighting technology. Adding smartness
to LED light further boost its superiority. Selective turn on/turn off
and brightness control results in increased system life and
reduced energy consumption. As input is from AC source and LED
is a constant current DC load, power quality is another major area
of concern for LED lighting which need to be taken care. The
recommended harmonic norms IEC61000-3-2 Class C, EMI limits
(CISPR 15) and Energy Star (standby consumption) are also
imposed for LED lighting. So diode bridge rectifier followed by
bulk capacitor is not recommended for power of LED lighting. The
proposed smart LED driver is taking care of all of the issues.
This article will discuss a Smart Home Light based on a
monolithic, offline LED driver and a BLE module which is
controlled by an Android application. This smart home lighting
system passes all the existing recommended norms of regulatory
authority. In addition, it has very low standby consumption. The
following Fig.1 shows the architecture block diagram of the BLE
based Smart Home Lighting System.

Fig.1 Functional Block Diagram of BLE Controlled Smart Home
Lighting System
Fig.2 shows the actual hardware of the Smart Home Lighting
System for the development of ready to manufacture solution.
This system implementation, has three major aspects, LED driver
power supply, microcontroller unit and the Android application
for user control. The LED driver is based on offline AC-DC
converter working on quasi resonant flyback mode with high
power factor (PF) and low total harmonic distortion (THD). Power
conversion is based on HVLED815PF, monolithic off-line primary
sensing constant current LED driver. For low cost and low power
applications, it is an ideal candidate as primary side regulation
does not need optocoupler for LED current feedback. It helps in
saving cost as well as PCB area. It meets the IEC61000-3-2 Class C
harmonic norms recommended by International Electrotechnical
Commission (IEC) for lighting system. The LED driver has a high

ELE Times | 34 | December, 2016