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Two, millet wireless car charger (WCJ02ZM) disassembly
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Remove the screws.
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Open the front panel to reveal the wireless charging coil.
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Wireless propaganda coil close-up.
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Open the back cover to expose the back assembly.
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The aluminum alloy lining inside the bracket increases the strength while strengthening the heat dissipation and reducing the temperature rise.
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A gear motor drives the phone holder to open or clamp the phone.
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There is foam adhesive inside the bracket to prevent slip.
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The gear motor is connected to the motherboard by a socket.
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The motor gearbox is very fine, and the power output shaft is white gear.
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Nidec's ultra-thin cooling fan.
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The circuit board on the back of the coil is coated with silicone grease to the internal aluminum bracket to help dissipate heat.
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The front of the circuit board is a graphite heat conductive patch for heat dissipation, and the right circle is a wireless charging coil.
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A large number of holes on the back of the coil, exposing copper, speeding up heat conduction.
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Air is injected into the circuit board through holes and blown out by fans to cool the circuit board.
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The shield above the fan is the circuit component of the wireless charge, and the infrared distance sensor is on the right side to detect whether the mobile phone is placed into the control bracket.
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Wireless charging coil, surrounded by a ring of LED for lamp effect, in the middle is a thermistor, used to detect the temperature during the charging process.
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Charging input Type-C interface, submerged plate, through hole welding.
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ES168 Touch detection chip.
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Infrared distance sensor, same as on the cell phone.
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Signal processing chip for infrared distance sensor.
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Resonant capacitance, 0.25μF.
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Remove the fan and connect the fan to the circuit board using a cable.
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The fan air intake is sealed with a ring of double-sided tape.
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Patch light effect LED close-up.
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Rip off the shield and see what's going on.
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Inside the largest shield is a full set of circuits for wireless charging, including a step-down circuit for constant frequency voltage regulation, a wireless charging control chip and an output power stage. The position of the patch NPO capacitor is reserved inside, and the CBB resonant capacitor is welded outside.
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Another step-down circuit looks like it powers the fan.
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The main control chip adopts IDT P9242 scheme, which is a highly integrated 15W wireless charging transmitter chip, supports the input voltage range of foreign body detection (FOD) 4.25V-21V, meets the WPC1.2 standard, has built-in overcurrent and overcurrent temperature protection, and supports programming LED mode.
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IDT IDTP9242 Specifications.
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Four VS.3618AE form the H-bridge, driving the coil.
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IDT solution unique 20mΩ current sampling resistance and firmware memory on the right.
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Synchronous rectifier buck chip, used to adjust the input voltage to meet the needs of different wireless charging.
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Disassemble the family photo.
The car charger is also disassembled from the front, and the leather decorative panel on the top is fixed through the buckle and can be pry open. There is also a translucent light guide plate on the motherboard, which is also secured by clasps.
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Take off the light guide plate, you can see that there are 40 LED lights on the motherboard. The top of the motherboard is welded with wireless charging coils and thermistors, reinforced by a bit of glue. There are three ports in the bottom hole of the mainboard: a supercapacitor, a cooling fan, and a USB Type-C port.
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The motherboard is fixed by screws, and there is an XH interface on the back to connect with the motor, a motor drive chip beside the motor interface, and a electret microphone at the bottom of the motherboard. The fan and motor are fixed by screws, and the clamping arms on both sides can be removed accordingly.