What's inside of a Wi-Fi-controlled light bulb? Find out in this Teardown Tuesday!

Wi-Fi- and app-connected peripherals are becoming very popular. All kinds of products are hooked up via Wi-Fi to our smart devices. For example, we have already done teardowns on products such as a Wi-Fi-connected power outlet and an app-enabled Bluetooth scale. In this Teardown Tuesday, we are going to take a look at a Wi-Fi-enabled light bulb.

 

The Wi-Fi-controlled LED bulb. Image courtesy of MagicLight.

 

The particular light bulb that we are going a teardown is a MagicLight model SY-XZ56-NAIT. This light build was purchased for around $30 and features the ability to not only control brightness but also color through a smartphone app.  

 

Opening It Up

 

The Opened Up LED Bulb

The opened LED bulb

 

This was probably the easiest teardown yet! Opening this light bulb was super easy. The plastic diffuser dome was simply pulled off to reveal a circuit board mounted with two Phillips head screws.

 

Circuit Board

With the screws removed, the shell of the LED light separated into three parts: the primary circuit board, the relatively large heatsink, and the base with the power supply. There were three wires connecting the two circuit board assemblies.

 

The low voltage PCB assembly

 

There is a low voltage assembly comprised of an aluminum core PCB and a Wi-Fi module.

 

The power supply module

 

Additionally, there is a power supply assembly comprised of two small circuit boards that are connected via long header pins.

 

LEDs!

To provide the illumination there are 20 discrete LEDs.

 

The warm white LEDs

 

There are 15 warm white LEDs and five RGB LEDs. The warm white LEDs are in a 3.2mm by 2.75mm package and the RGB LEDs are in a 5mm by 5mm package. Each of the LEDs (Red, Green, Blue, White) are controlled through individual outputs from the WiFi Module.

 

The RGB LEDs

 

The outputs of the Wi-Fi module are buffered through four transistors since they draw more current than the Wi-Fi module can supply.

 

The buffering transistors

 

Wi-Fi Module

Packed into this light bulb is everyone’s favorite Wi-Fi module, an ESP8266! This is the “07” version of the module with a U.FL connector.

 

The ESP8266-07 Wi-Fi module

 

This Wi-Fi module is soldered onto a breakout board that connects up to the LED board. The antenna paired to this module slides down next to the power supply module. To prevent short circuits, the antenna is covered with heat shrink. To prevent the U.FL from coming detached from the Wi-Fi module, a small amount of red adhesive is used.

 

Power Supply

 

The power supply module

 

To power the LEDs in this light bulb a dual output power supply was used. The primary power supply is a 120VAC-to-17VDC power supply. This supply is used to power a DC-to-DC converter and the LEDs. This AC-to-DC power supply is comprised of a large 10uF input capacitor, an STMicroelectronic VIPer22A-E (PDF) switcher, a transformer, and output smoothing capacitors. 

 

 

In order to power the Wi-Fi module, a DC-to-DC converter is used. This module is attached to the power supply using a three header pin. This is on a small PCB that measures 11mm by 17mm.

 

Today Wi-Fi and app-controlled devices are the growing trend. With Wi-Fi modules becoming very inexpensive (only a few dollars), more and more devices will become connected in the near future.  

Stop by next Tuesday for another teardown! 

 

Next Teardown:

 

Comments

2 Comments


  • Marley 2016-08-18

    Does the power supply have any isolation? Slightly worried the plastic diffuser comes off very easily exposing possibly live parts. At least it’s got a heatsink!

  • Pangle 2016-08-20

    17 volts not likely a concern for ‘live parts’