Huawei Sound A speaker combination with a built-in 50W low-frequency unit, four 5W mid-frequency units and a 3W high-frequency unit, combined with two passive radiators, forms a three-way speaker system.

At the same time, this speaker is also a super terminal of the HarmonyOS system. It supports the connection of Huawei mobile phones, tablets and Android phones. It has seven single colors and one mixed color, and has smart lighting effects and smart home control. . It also supports two speakers to form a wireless stereo, which can be used with a smart screen and is an important part of Huawei's smart home.

Charging Head Network has obtained the power adapter for this speaker. The power supply is 65W, 24V2.71A output, fixed cable. Let’s take a look at the disassembly of this power supply.

The body style of this adapter is a very classic Huawei original charger style, with a high-gloss finish on the casing.

The front and back of the fuselage are designed with small concave surfaces to facilitate user insertion and removal.

Equipped with fixed national standard pins, arranged on one side.

The adapter parameters are printed on the input shell

Model: HW-240271C00

Input: 100-240V~50/60HZ 1.5A

Output: 24V2.71A

Manufacturer: Shenzhen Hangjia Chiyuan Electric Co., Ltd.

The adapter has passed CCC certification and VI level energy efficiency certification.

In addition, the adapter comes with a DC round head output cable.

The junction between the cable and the fuselage has been treated to resist bending.

The 90° bend design of the end makes speaker layout easier.

The measured height of the adapter body is 69.63mm.

The width is 69.68mm.

Thickness is 29.2mm.

In addition, the cable length was measured to be approximately 1.5 meters.

The body size is similar to Apple’s 60W charger.

You can intuitively feel the size in your hand.

The total weight of the adapter with cable is approximately 241g.

After having a basic understanding of the appearance, size and parameters of the original 65W adapter of Huawei Sound Material workmanship.

Remove the case from the pin side of the charger. There is foam cushioning inside the case. The input pins are connected to the PCBA module through wires, and the solder joints of the wires are glued to reinforce the insulation.

The charger PCBA module is completely wrapped with a heat sink and fixed with buckles.

The heat sink on the back of the PCBA module is fixed with buckles and soldering.

Remove the heat sink, apply white glue between the transformer and the components to conduct heat, and put an insulating sheet and thermal pad between the back of the circuit board and the heat sink to distribute the heat evenly.

The input wires are first pressed into the terminals and then welded, and reinforced with glue.

Close-up of the thermal pad on the back of the PCBA.

The measured module length is 65.72mm.

The width is 66.2mm.

The thickness is 25.22mm.

PCB front view, input varistor and thermal fuse are connected in series for abnormal input overvoltage protection, input slow-blow fuse, *** mode inductor, NTC thermal suppression resistor and other components are included Everything. Both the primary switch tube and the secondary Schottky diode have heat sinks, and the output is filtered by solid capacitors.

There are multiple silicone pads on the back of the PCBA to support the gap between the back heat sink and the PCB.

On the back are the primary PWM controller and the optocoupler for output voltage feedback, as well as the corresponding peripheral components.

Through observation, we found that this power adapter adopts a flyback switching power supply architecture design and outputs a fixed voltage. Considering that the output voltage is high, the current is small, and the speaker power supply is discontinuous, Schottky rectification is used. In addition, the varistor at the power input end is connected in series with a thermal fuse for overheating protection, and the internal large-area heat dissipation design is suitable for long-term plug-in operation. Let's learn about each device one by one starting from the input end.

The slow-blow fuse at the power input terminal is from Better Electronics, and the fuse specification is 3.15A 250V.

The varistor is from Celtic, SFV10D561KT. When an overvoltage occurs, the resistor breaks down and cuts off the fuse to protect other circuits inside the charger.

Close-up of the thermal fuse, Celtic ATCO alloy type, Y series, rated current 5A, rated operating temperature 130, fixed together with the varistor using heat shrink tube, used to monitor the temperature of the varistor. Cut off the connection between the varistor and the circuit when the temperature is too high.

NTC thermistor that suppresses power-on surge current, model 10S2R5M, is used to suppress the surge current when the adapter is plugged in to prevent sparking.

Safety X2 capacitor, 0.47μF, used to suppress differential mode interference.

The *** mold inductor is made of magnetic surround. There is an insulating plate between the two coils to strengthen the insulation, and the bottom is reinforced with an insulating plate.

The input alternating current enters the rectifier bridge after passing through the fuse and EMI filter circuit, and is converted into pulsating direct current by the rectifier bridge.

The primary filter capacitor is from AiSHi. The HS series has a high temperature resistance of 115 and 450V120μF.

The main control chip power supply capacitor specification is 50V10μF.

The primary controller of the switching power supply is screen-printed SHt and packaged in SOT23-6.

The primary switch tube is from Toshiba, TK13A65U, NMOS, with a voltage resistance of 650V, a conduction resistance of 0.32Ω, and a TO220F package. The switch tube is fixed on the heat sink to enhance heat dissipation.

Close-up of high-voltage ceramic capacitor used in flyback RCD absorption circuit, 10nF, withstand voltage 1000V.

Close-up of the transformer, tightly wrapped with insulating tape.

The output Schottky rectifier is from Pingwei, PSM30U150CT, 30A, withstand voltage 150V, used for adapter output rectification. Using Schottky diodes here allows for faster transient response.

EL1019 optocoupler for feedback output voltage.

Close-up of two Y capacitors.

Since the output voltage of the adapter is 24V, a solid capacitor with a voltage resistance of 35V is used for filtering. The first one is 820μF 35V.

The other solid capacitor is 1000μF 35V.

The output filter inductor is made of double wire winding, and an insulating plate is fixed at the bottom of the magnetic ring to isolate it from the PCB.

Close-up of the output line, which adopts a coaxial structure and has a wire card welded on the PCB to fix the output line.

Now that everything has been dismantled, let’s take a family photo.

Generally speaking, smart speakers are usually powered 24 hours a day and are very convenient to use at any time. Huawei has optimized the power adapter of Sound X 2021 based on the application habits of smart speakers. First, the input varistor and the thermal fuse are fixed together using heat shrink tubing, which can cut off the power supply when the varistor overheats abnormally to ensure safety.

The large-area heat sink is used internally to help dissipate heat during long-term high-power operation. Both the switching tube and the output rectifier tube use large-area metal heat sinks, which can effectively dissipate heat. In view of the unstable load characteristics of speaker products, Schottky diodes are used inside the power supply instead of the widely used synchronous rectifier to obtain better transient response.

During the disassembly, it was also discovered that this power supply is manufactured by Hangjia, a major manufacturer in the industry. It uses Toshiba primary switching tubes and Pingwei Schottky rectifiers internally. The capacitors use AiSHi high-temperature resistant series. It can effectively ensure the reliability of power supply during the product life cycle and meet the needs of 24-hour power supply.