preface
Huawei Sound X 2021 is Huawei's third-generation Sound series of smart speakers, which adopt a new design concept and incorporate more fashionable and youthful elements into the elegant design. A built-in 50W low-frequency unit plus four 5W intermediate frequency units and a 3W high-frequency unit speaker combination, with two passive radiators, constitute a three-way loudspeaker system.
At the same time, this speaker is also a super terminal of HarmonyOS Hongmeng system, supporting Huawei mobile phones, tablets and Android mobile phone connections, with seven monochrome and one color mix, and has smart lighting effects, with smart home control. At the same time, it also supports two speakers to form wireless stereo sound, which can be used with smart screens, which is an important part of Huawei's smart home.
The charging head network got the power adapter supporting this speaker, the power supply is 65W power, 24V2.71A output, fixed cable, let's take a look at the disassembly of this power supply.
Huawei Sound X 2021 speaker original 65W adapter out of the box
The body style of this adapter is a very classic Huawei original charger style, and the shell is high-gloss processed.
The front and back of the fuselage are designed with small concave surfaces for easy user insertion and removal.
Equipped with fixed GB pins, one side layout.
The input housing is printed with adapter parameters
Model:HW-240271C00
Input: 100-240V~50/60HZ 1.5A
Output: 24V2.71A
Manufacturer: Shenzhen Hangjia Chiyuan Electric Co., Ltd
The adapter is CCC certified as well as Class VI Energy Efficiency Certified.
The adapter also comes with a DC round-toe output cable.
The junction between the cable and the fuselage is bent.
The 90° curved design of the end head facilitates the layout of the speaker.
The measured height of the adapter body was 69.63mm.
The width is 69.68mm.
The thickness is 29.2mm.
In addition, the length of the cable measured is about 1.5 meters.
The body volume is comparable to that of the Apple 60W charger.
The size of the hand is intuitive.
The total weight of the adapter strip cable is about 241g.
Huawei Sound X 2021 speaker original 65W adapter disassembled
After a basic understanding of the appearance, size and parameters of the original 65W adapter of Huawei Sound X 2021 speaker, the following charging head network will disassemble it in detail, let's take a look at the specific material workmanship of this adapter.
Detach the housing from the charger pin side with foam cushioning inside. The input pins are connected to the PCBA module by wires, and the wire solder joints are glued to reinforce the insulation.
The charger PCBA module is completely wrapped with a heatsink and snaps in place.
The heatsink on the back of the PCBA module is fastened with snaps and soldering.
Remove the heat sink, coat the transformer and the component with white glue filling and heat conduction, and paste the insulation sheet and thermal pad between the back of the circuit board and the heat sink to distribute the heat evenly.
The input terminal wires are pressed first and then welded, and reinforced with glue.
Close-up of the thermal pad on the back of the PCBA.
The measured module length was 65.72mm.
The width is 66.2mm.
The thickness is 25.22mm.
At a glance on the front of the PCB, the input varistor is connected in series with the temperature fuse for input abnormal overvoltage protection, and the input slow melt fuse, common mode inductor, NTC thermistor and other components are readily available. Both the primary switch and the secondary Schottky diode have heat sinks and the output is filtered with a solid capacitor.
There are multiple silicone pads on the back of the PCBA that support the void between the heat sink on the back and the PCB.
On the back are the primary PWM controller and optocoupler for output voltage feedback, along with the corresponding peripheral components.
Through observation, it was found that this power adapter adopts a flyback switching power supply architecture design and outputs a fixed voltage. Considering the high output voltage, small current, and discontinuous power supply of the speaker, the Schottky rectifier method is adopted. And the power supply input varistor series temperature fuse for overtemperature protection, internal large area heat dissipation design, suitable for long-term plug-in operation. Let's take a look at each device from the input.
The slow-melt fuse at the power input is from Bate Electronics with a fuse size of 3.15A 250V.
The varistor comes from SERT, SFV10D561KT, which breaks down the resistor in the event of an overvoltage condition, cutting off the fuse and protecting other circuitry inside the charger.
Close-up of the temperature fuse, SELTER ATCO alloy type, Y series, rated current 5A, rated operating temperature 130 ° C, and varistors are fixed together using heat shrink tubes to monitor the temperature of the varistors and cut off the connection of the varistors to the circuit when the temperature is too high.
NTC thermistors that suppress power-up inrush current, Model 10S2R5M, are designed to suppress inrush current when the adapter is plugged in and prevent ignition.
Safety X2 capacitor, 0.47μF, for rejection of differential mode interference.
The common mode inductor adopts a magnetic surround system, and there is an insulating plate between the two coils to strengthen the insulation, and the bottom is reinforced by an insulation plate.
The input AC power enters the rectifier bridge after passing through the fuse and EMI filter circuit, which is converted from the rectifier bridge to a pulsating DC current.
The primary filter capacitor comes from AiSHi Aihua, HS series high temperature resistance 115°C, 450V120μF.
The power supply capacitor specification of the main control chip is 50V10μF.
Switching power supply primary controller silkscreen SHt in SOT23-6 package.
Primary switch tubes from Toshiba, TK13A65U, NMOS, withstand voltage 650V, conductivity 0.32Ω, available in TO220F package. The switch tube is fixed on the heat sink to enhance heat dissipation.
High voltage ceramic capacitor close-up for flyback RCD absorption circuit, 10nF, withstand voltage 1000V.
Close-up of the transformer, tightly wound using insulating tape.
Output Schottky rectifier from Pingwei, PSM30U150CT, 30A, withstand voltage 150V for adapter output rectification. Using a Schottky diode here allows for a faster transient response.
EL1019 optocoupler for feedback output voltage.
Two close-ups of two Y capacitors.
Since the output voltage of the adapter is 24V, a solid capacitor filter with a withstand voltage of 35V is used here, and the first one is 820μF 35V.
The other solid capacitor is 1000μF 35V.
The output filter inductor is two-wire wound with an insulating plate fixed at the bottom of the magnetic ring isolated from the PCB.
The output line is close-up, using a coaxial structure, and the output line is fixed by welding a wired card on the PCB.
All disassembled, let's take a family portrait.
Charging head net disassembly summary
In general, smart speakers are usually 24 hours of uninterrupted power, which is very convenient to use at any time. Huawei has optimized the power adapter of Sound X 2021 in view of the application habits of smart speakers. The first is that the input varistor and the temperature fuse are fixed together using a heat shrink tube, which can cut off the power supply when the varistor is abnormally overheating, ensuring safety.
The internal use of large-area heat sink, to help long-term high-power operation of heat dissipation, switch tube and output rectifier are used large-area metal heat sink, can effectively dissipate heat. In view of the unstable load characteristics of speaker products, the use of Schottky diodes inside the power supply instead of the use of extensive synchronous rectification can obtain better transient response.
In the disassembly, it was also found that this power supply is manufactured by Hangjia, a major manufacturer in the industry, with Toshiba primary switch tubes inside, with Pingwei Schottky rectifier tubes, and the capacitor adopts AiSHi high temperature resistant series, which can effectively ensure the reliability of the power supply during the life cycle of the product and meet the needs of 24-hour power supply.