Electrically powered sickbed wireless charger

Abstract

The utility model is suitable for electric sickbed charging field, provide electric sickbed wireless charger, including fixed in the transmitting end of sickbed ground / bed body base, and integrated in the receiving end of electric sickbed, transmitting end is connected AC - DC power converter, DC - DC power control circuit, full bridge / half bridge inverter circuit, LC compensation topology with ferrite magnetic shielding's litz wire transmitting coil in proper order, still is equipped with bluetooth receiving module, receiving end is connected with transmitting end matched receiving coil, full bridge synchronous rectifier circuit, CLC filter, DC - DC circuit, 24V lithium cell in proper order, still is equipped with MCU, battery / power device temperature sensor, bluetooth communication module, and MCU is connected with sensor, bluetooth module, charge / M main loop MOSFET signal respectively, in the utility model, realize non - contact charging through electromagnetic induction, possess voltage - temperature two - dimensional adaptive power adjustment, integrated battery overvoltage / undervoltage / overcurrent / short circuit multiple protection.

Description

Technical Field

[0001] This utility model belongs to the field of electric hospital bed charging, and particularly relates to a wireless charger for electric hospital beds. Background Technology

[0002] Safety hazards and electromagnetic interference issues with wired charging: Most electric beds in existing ICU wards use wired charging. The charging cables are easily tangled with moving parts of the bed and other medical equipment, posing a risk of tripping medical staff or cable wear and leakage. Some wireless charging devices use ordinary wire coils, which suffer from high losses due to skin effect and proximity effect at high frequencies. They also lack magnetic shielding, resulting in excessive electromagnetic radiation (EMI) that interferes with precision monitoring equipment in the ICU. In addition, the energy transmission efficiency is less than 80%, which cannot meet the requirements for long-term battery life. The problem of shortened battery life caused by non-adjustable power: Traditional charging devices lack the ability to adaptively adjust based on battery status. They cannot achieve a smooth transition from CC (constant current) to CV (constant voltage) stages according to battery voltage, nor can they dynamically adjust the power according to the temperature of the battery and power devices. This can easily lead to overcharging of the battery, damage to the plates, or burnout of power devices due to continuous high temperature, thus shortening the service life of the equipment. Single protection mechanism and data security issues: The existing device only has basic overcurrent protection and lacks medical-grade multi-layer protection such as battery overvoltage / undervoltage, power device overtemperature, and input overvoltage / undervoltage. The fault response speed is slow (more than milliseconds); Bluetooth communication is not encrypted, and medical data such as battery voltage and temperature can be easily tampered with, which does not meet the ICU medical data security standards. In addition, it is impossible to quickly locate and alarm when a fault occurs, which increases the difficulty of operation and maintenance. Therefore, a wireless charger for electric hospital beds is needed to solve the above problems. Utility Model Content

[0003] The purpose of this utility model embodiment is to provide a wireless charger for electric hospital beds to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: The wireless charger for electric hospital beds includes a transmitter and a receiver. The transmitter is fixed to the floor or base of the hospital bed. Inside the transmitter, an AC-DC power converter, a DC-DC power control circuit, a full-bridge / half-bridge inverter circuit, and a transmitting coil are connected sequentially along the power transmission path. The transmitting coil is wound with Litz wire and is externally shielded with ferrite. The transmitting coil is connected in series with an LC compensation topology. The transmitter is also equipped with a Bluetooth receiver module, which is electrically connected to the DC-DC power control circuit via a signal line. The receiver is integrated inside the electric hospital bed. Inside the receiver, along the energy conversion path, the receiving coil, the full-bridge synchronous rectifier circuit, the CLC filter, the DC-DC circuit, and the 24V lithium battery are connected in sequence. The receiving coil has the same parameters as the transmitting coil, and the receiving coil is connected in series with an LC compensation topology; the receiving end is also equipped with an MCU, two battery pack digital temperature sensors, a transmitting end NTC thermistor, a receiving end NTC thermistor, and a Bluetooth communication module; The signal input terminal of the MCU is electrically connected to two battery pack digital temperature sensors, a transmitter NTC thermistor, a receiver NTC thermistor, a battery voltage monitoring module, and a current sampling resistor via signal lines. The signal output terminal of the MCU is electrically connected to the Bluetooth communication module, the charging MOSFET, and the main circuit MOSFET respectively via signal lines; The Bluetooth communication module communicates wirelessly with the Bluetooth receiver module at the transmitting end.

[0005] A further technical solution is that the power input terminal of the AC-DC power converter is compatible with AC180V~240V, 50 / 60Hz mains power, and the power output terminal outputs 48V DC. The rated output power of the AC-DC power converter is 150W. The DC-DC power control circuit has a voltage output range of 5~42Vdc and a current output range of 0~7A.

[0006] In a further technical solution, the switching device of the full-bridge / half-bridge inverter circuit is an N-channel MOSFET with a rated voltage of 100V, a rated current of 120A, and an on-resistance of 3.7mΩ. The switching devices of the full-bridge synchronous rectifier circuit are low-Rdson MOSFETs; the CLC filter is composed of a capacitor and an inductor connected in series.

[0007] In a further technical solution, the battery voltage monitoring module is electrically connected to the MCU via a signal line. The MCU sends a power adjustment signal to the transmitting Bluetooth receiving module via the Bluetooth communication module. The transmitting Bluetooth receiving module transmits the signal to the DC-DC power control circuit to adapt to the charging voltage requirements of the 24V lithium battery.

[0008] A further technical solution involves two battery pack digital temperature sensors for acquiring the temperature of the 24V lithium battery, an NTC thermistor for acquiring the temperature of the transmitting power device, and an NTC thermistor for acquiring the temperature of the receiving power device. Based on the temperature signal collected by the aforementioned sensor, the MCU controls the switching on and off of the charging MOSFET and transmits a power adjustment signal to the DC-DC power control circuit via the Bluetooth communication module to achieve temperature protection for the 24V lithium battery and power devices.

[0009] A further technical solution is that the battery voltage monitoring module includes a voltage divider resistor branch. The MCU collects the 24V lithium battery voltage through this branch. When the voltage reaches 29.2V, it triggers a first-level warning. When it reaches 29.5V, it controls the main circuit MOSFET to disconnect. When the voltage is lower than 21.5V, it controls the main circuit MOSFET to disconnect. The current sampling resistor is electrically connected to the MCU. The MCU collects the charging circuit current through this resistor. When the current reaches 1.5 times the rated current, it triggers overcurrent protection. When it reaches 5 times the rated current, it controls the main circuit MOSFET to disconnect. When any of the above protection states are triggered, the MCU sends an alarm signal via the Bluetooth communication module.

[0010] In a further technical solution, the Bluetooth communication module is electrically connected to the MCU via a signal line, and has wireless signal transceiver hardware functions. It can establish a wireless communication link with the transmitting Bluetooth receiving module, and can also establish a wireless connection with an external terminal to achieve signal interaction.

[0011] In a further technical solution, both the transmitter and receiver are equipped with a PCB. The PCB adopts a symmetrical structure design and has a mounting size of 180mm×80mm×190mm. The PCB is fixed to the back of the heat sink through threaded holes on the back plate, and an M3 mounting hole is provided at the bottom of the PCB. The device has an energy transmission efficiency of >80%, an effective transmission distance of 28mm±10%, and an X / Y plane alignment tolerance range of ±20mm.

[0012] Compared with the prior art, the beneficial effects of this utility model are: This invention eliminates the hidden dangers of wired charging, reduces electromagnetic interference, and improves energy transmission stability. The device utilizes a "transmitter-receiver electromagnetic induction transmission" hardware structure to completely avoid the risk of tripping or leakage caused by wired charging cables tangling with moving parts of the bed or medical equipment. The transmitting and receiving coils are wound with Litz wire and fitted with ferrite magnetic shielding, effectively reducing skin effect and proximity effect losses at high frequencies. Simultaneously, it constrains the magnetic field direction, reducing electromagnetic radiation interference to precision monitoring equipment in the ICU. The LC compensation topology hardware structure, with coils connected in series, ensures a constant resonant frequency. Combined with the hardware adaptation of full-bridge / half-bridge inverter circuits and full-bridge synchronous rectifier circuits, the energy transmission efficiency is increased to over 80%, with an effective transmission distance of 28mm ± 10% and an X / Y plane alignment tolerance range of ± 20mm, adapting to the movement deviation of the electric hospital bed and preventing charging interruptions. This invention optimizes the hardware protection structure, enhancing the safety and durability of the equipment: the receiver is equipped with a dual-battery pack digital temperature sensor and an NTC thermistor at both the transmitter and receiver ends, which are connected to the MCU hardware via signal lines to collect the temperature of the lithium battery and power devices in real time; the battery voltage monitoring module (including the voltage divider resistor branch) and the current sampling resistor respectively collect voltage and current signals and transmit them to the MCU; the MCU signal output terminal is directly connected to the charging MOSFET and the main circuit MOSFET. When the overvoltage (29.2V warning, 29.5V shutdown), undervoltage (21.5V shutdown), overcurrent (1.5 times rated current), and short circuit (5 times rated current) protection thresholds are triggered, the MOSFET can be quickly controlled to disconnect via hardware signals. The short circuit protection response speed reaches the microsecond level, avoiding overcharging of the lithium battery, damage to the plates, or high-temperature burnout of the power devices, thus extending the service life of the equipment; This invention simplifies hardware layout and improves installation adaptability and signal transmission stability: the transmitter and receiver PCBs adopt a symmetrical structure design with uniform installation dimensions of 180mm×80mm×190mm. M3 mounting holes are provided at the bottom, and the device is fixed to the heat sink via a backplate thread, simplifying the production assembly process while ensuring efficient heat dissipation of power devices, keeping the operating temperature of the transmitter power devices ≤40℃. The receiver Bluetooth communication module connects to the MCU hardware via a signal line, establishing a wireless communication link with the transmitter Bluetooth receiver module to transmit battery voltage, current, and device status signals collected by the hardware. A 1kΩ signal isolation resistor is added to the module hardware interface to enhance anti-interference capabilities in the complex electromagnetic environment of the ICU, ensuring stable transmission of charging parameters and protection status signals.

[0013] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0014] Figure 1 This is a system architecture diagram of the present invention; Figure 2 This is the PCB layout diagram of the transmitter of this utility model; Figure 3 This is the PCB layout diagram of the receiver of this utility model; Figure 4 This is a PCB mounting dimension diagram of this utility model; Figure 5 This is a schematic diagram of the DC-DC power control circuit of this utility model; Figure 6 This is the schematic diagram of the full-bridge inverter / rectifier circuit of this utility model. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0016] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0017] Example 1 like Figures 1-6 As shown, this utility model embodiment provides a wireless charger for an electric hospital bed, including a transmitter and a receiver; The transmitter is fixed to the floor of the hospital bed. Internally, along the power transmission path, it is sequentially connected to an AC-DC power converter (Model Mean Well RPS-150-48), a DC-DC power control circuit (Model TITPS5430), a full-bridge inverter circuit (MOSFET Model IRF3205), and a transmitting coil via wires. The transmitting coil is wound with 200×0.1mm Litz wire (22 turns in total), and the coil is externally shielded with PC95 ferrite magnetic shield (size 82.5mm×65mm×3mm). The transmitting coil is connected in series with an LC compensation topology (capacitor value 10nF, inductor value adapted). The transmitter also has a Bluetooth receiver module (Model nRF52832), which is electrically connected to the DC-DC power control circuit via a signal line. The receiver is integrated inside the electric hospital bed. Internally, along the energy conversion path, it is sequentially connected via wires to the receiving coil, a full-bridge synchronous rectifier circuit (MOSFET model IRF3205), a CLC filter (C3-C4 are 100V-10μF capacitors, C5-C8 are 50V-10μF capacitors, in conjunction with inductor L1), a DC-DC circuit (model TITPS5450), and a 24V lithium battery. The receiving coil has the same parameters as the transmitting coil (Litz wire specifications, number of turns, and magnetic shielding structure are identical), and is connected in series with an LC compensation topology matched to the transmitting end. The receiver also includes an MCU (model STM32L476), two battery pack digital temperature sensors (model DS18B20), and a transmitting... The system includes an NTC thermistor (10kΩ@25℃) at the transmitter end, an NTC thermistor (10kΩ@25℃) at the receiver end, and a Bluetooth communication module (model nRF52832). The MCU's signal input terminals are electrically connected via signal lines to two battery pack digital temperature sensors, the transmitter NTC thermistor, the receiver NTC thermistor, the battery voltage monitoring module (including voltage divider resistors R12-R13, 36kΩ), and the current sampling resistor R1 (10mΩ). The MCU's signal output terminals are electrically connected via signal lines to the Bluetooth communication module, the charging MOSFET, and the main circuit MOSFET. The Bluetooth communication module establishes a communication link with the transmitter Bluetooth receiver module via wireless signals. Both the transmitter and receiver are equipped with PCB boards. The PCB boards adopt a symmetrical structure design and have an installation size of 180mm×80mm×190mm. The PCB boards are fixed to the back plate and the back of the heat sink with threaded holes (using M3 screws). The bottom of the PCB board has M3 mounting holes (for overall fixation).

[0018] In this embodiment, the mains power (AC180V~240V, 50 / 60Hz) is connected to the AC-DC power converter at the transmitting end, and after AC-DC conversion, it outputs a 48V DC voltage. The 48V DC voltage is input to the DC-DC power control circuit, and after closed-loop regulation, it outputs a DC voltage adapted to the full-bridge inverter circuit. The MCU outputs a high-frequency PWM signal (hardware pin output) to drive the MOSFETs of the full-bridge inverter circuit to conduct alternately, converting the DC voltage into high-frequency AC current. When the high-frequency AC current passes through the transmitting coil, under the action of the LC compensation topology, the transmitting coil generates a stable alternating magnetic field. The receiving coil is in an alternating state. Within the magnetic field range, magnetic field energy is collected through electromagnetic induction and high-frequency alternating current is output. The high-frequency alternating current output from the receiving coil is input into a full-bridge synchronous rectifier circuit, which converts it into DC voltage. This DC voltage is filtered by a CLC filter to remove ripple before being input into a DC-DC circuit. The DC-DC circuit adjusts the rectified and filtered DC voltage to a charging voltage (25.6V) suitable for a 24V lithium battery, ultimately powering the 24V lithium battery. According to actual measurements, the energy transmission efficiency of this device is >80%, the electromagnetic radiation value is <30dBμV / m, the effective transmission distance is 28mm±10%, and the X / Y plane alignment tolerance range is ±20mm.

[0019] Example 2 The difference between this embodiment and Embodiment 1 is that the full-bridge inverter circuit at the transmitting end is replaced with a half-bridge inverter circuit (only MOSFETs Q1-Q2 are retained and connected to other parts of the circuit through wires); in the hardware structure of the half-bridge inverter circuit, the connection method of the MOSFETs is adapted to the full-bridge inverter circuit, and the capacitance value of the LC compensation topology is adjusted to 12nF (to match the hardware parameters of the half-bridge inverter circuit). In the hardware structure of the battery voltage monitoring module at the receiving end, a new voltage divider resistor branch (connected in parallel with the original R12-R13 branch, with the same resistance value as R12-R13) is added to enhance the stability of voltage acquisition.

[0020] In this embodiment, the hardware structure of the half-bridge inverter circuit reduces the number of MOSFETs by two, thereby reducing the heat generation power of the transmitter hardware. According to actual measurements, the operating temperature of the transmitter power device is ≤40℃, and the energy transmission efficiency is still ≥80%. The newly added voltage divider resistor branch at the receiver ensures that the deviation range of battery voltage acquisition is ≤±0.1V. The transmitter is integrated into the bed base (fixed to the base hardware structure by M3 screws), reducing the space occupied for ground installation. Moreover, after the coil spacing is shortened, the device can still maintain stable charging when the X / Y plane offset is ±18mm.

[0021] Example 3 The difference between this embodiment and embodiment 2 is that an ambient temperature sensor (model SHT30) is added to the receiving end, and the ambient temperature sensor is electrically connected to the signal input terminal of the MCU through a signal line. A new input voltage monitoring module (including sampling resistor R4, with a resistance of 10mΩ) is added to the transmitter. The input voltage monitoring module is electrically connected to the signal transmission circuit inside the transmitter through a signal line, and the signal transmission circuit is electrically connected to the signal input terminal of the receiver MCU through a wire. A new signal isolation resistor (1kΩ) has been added to the hardware interface of the Bluetooth communication module to enhance the anti-interference capability of wireless communication.

[0022] In this embodiment, the hardware connection structure of the ambient temperature sensor enables the acquisition of the ambient temperature in the ICU ward; the hardware structure of the input voltage monitoring module enables the acquisition of the mains voltage signal connected to the transmitter; when the mains voltage is <180V or >240V, the signal acquired by the input voltage monitoring module is transmitted to the MCU, and the MCU controls the main circuit MOSFET to disconnect through the output signal of the hardware pin; according to actual measurement, the response time of this protection action is ≤10ms; the newly added isolation resistor of the Bluetooth communication module enables the module to still transmit signals stably in the complex electromagnetic environment of the ICU; when all hardware protection structures of the device are triggered, the MCU outputs signals to the Bluetooth communication module through the hardware pin, and the Bluetooth communication module transmits hardware status signals to the outside.

[0023] Working principle and usage process of this utility model: The AC mains power (AC180V~240V, 50 / 60Hz) is connected to the AC-DC power converter at the transmitter, and after AC-DC conversion, it outputs 48V DC voltage. The DC-DC power control circuit is input with a 48V DC voltage. After closed-loop regulation by the DC-DC circuit, the output DC voltage is adapted to the full-bridge / half-bridge inverter circuit. The high-frequency PWM signal output by the MCU drives the MOSFETs of the full-bridge / half-bridge inverter circuit to conduct alternately, converting DC voltage into high-frequency AC current. The high-frequency AC current passes through the transmitting coil, and under the action of the LC compensation topology, the transmitting coil generates a stable alternating magnetic field. The receiving coil and the transmitting coil are within an alternating magnetic field range. Magnetic field energy is collected through electromagnetic induction, and high-frequency alternating current is output. The high-frequency AC power output from the receiving coil is input into a full-bridge synchronous rectifier circuit, where it is rectified and converted into DC voltage. This DC voltage is then filtered out for ripple by a CLC filter before being input into a DC-DC circuit. The DC-DC circuit adjusts the rectified and filtered DC voltage to a charging voltage suitable for the 24V lithium battery, ultimately providing stable charging power for the 24V lithium battery. Voltage and current protection: The battery voltage monitoring module collects the voltage signal of the 24V lithium battery through a voltage divider resistor, and the current sampling resistor collects the current signal of the charging circuit. Both signals are transmitted to the MCU. Based on the signals collected by the hardware, the MCU controls the switching on and off of the MOSFET in the main circuit to achieve protection against battery overvoltage, undervoltage, charging overcurrent, and short circuit. Temperature protection: The battery pack digital temperature sensor collects the lithium battery temperature signal, and the transmitter / receiver NTC thermistor collects the temperature signal of the corresponding power device. The above temperature signals are transmitted to the MCU. The MCU controls the on and off of the charging MOSFET and transmits the power adjustment signal to the DC-DC power control circuit based on the temperature signal to realize the temperature protection of the lithium battery and power device. Signal interaction: The Bluetooth communication module at the receiving end establishes a wireless signal link with the Bluetooth receiving module at the transmitting end. The MCU transmits power adjustment-related signals to the DC-DC power control circuit through this link to ensure that the output power of the transmitting end matches the charging needs of the receiving end. The Bluetooth communication module also supports wireless connection with external terminals to realize the transmission of device status signals.

[0024] The circuits, electronic components, and modules involved are all existing technologies, which can be fully implemented by those skilled in the art, and need not be elaborated upon. The content protected by this utility model does not involve any improvement to the software and methods.

[0025] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A wireless charger for an electric hospital bed, comprising a transmitter and a receiver, characterized in that: The transmitter is fixed to the floor of the hospital bed or the bed base. Inside the transmitter, along the power transmission path, an AC-DC power converter, a DC-DC power control circuit, a full-bridge / half-bridge inverter circuit, and a transmitting coil are connected in sequence. The transmitting coil is wound with Litz wire and has a ferrite magnetic shield attached to its exterior. The transmitting coil is connected in series with an LC compensation topology. The transmitter is also equipped with a Bluetooth receiver module, which is electrically connected to the DC-DC power control circuit via a signal line. The receiver is integrated inside the electric hospital bed. Inside the receiver, along the energy conversion path, the receiving coil, the full-bridge synchronous rectifier circuit, the CLC filter, the DC-DC circuit, and the 24V lithium battery are connected in sequence. The receiving coil has the same parameters as the transmitting coil, and the receiving coil is connected in series with an LC compensation topology; the receiving end is also equipped with an MCU, two battery pack digital temperature sensors, a transmitting end NTC thermistor, a receiving end NTC thermistor, and a Bluetooth communication module; The signal input terminal of the MCU is electrically connected to two battery pack digital temperature sensors, a transmitter NTC thermistor, a receiver NTC thermistor, a battery voltage monitoring module, and a current sampling resistor via signal lines. The signal output terminal of the MCU is electrically connected to the Bluetooth communication module, the charging MOSFET, and the main circuit MOSFET respectively via signal lines; The Bluetooth communication module communicates wirelessly with the Bluetooth receiver module at the transmitting end.

2. The wireless charger for electric hospital beds according to claim 1, characterized in that: The AC-DC power converter is compatible with AC180V~240V, 50 / 60Hz mains power at the power input terminal and outputs 48V DC at the power output terminal. The rated output power of the AC-DC power converter is 150W. The DC-DC power control circuit has a voltage output range of 5~42Vdc and a current output range of 0~7A.

3. The wireless charger for electric hospital beds according to claim 1, characterized in that: The switching device of the full-bridge / half-bridge inverter circuit is an N-channel MOSFET with a rated voltage of 100V, a rated current of 120A, and an on-resistance of 3.7mΩ. The switching devices of the full-bridge synchronous rectifier circuit are low-Rdson MOSFETs; the CLC filter is composed of a capacitor and an inductor connected in series.

4. The wireless charger for electric hospital beds according to claim 1, characterized in that: The battery voltage monitoring module is electrically connected to the MCU via a signal line. The MCU sends a power adjustment signal to the transmitting Bluetooth receiving module via the Bluetooth communication module. The transmitting Bluetooth receiving module transmits the signal to the DC-DC power control circuit to adapt to the charging voltage requirements of the 24V lithium battery.

5. The wireless charger for electric hospital beds according to claim 4, characterized in that: Two battery pack digital temperature sensors are used to acquire the temperature of the 24V lithium battery, an NTC thermistor at the transmitting end is used to acquire the temperature of the transmitting power device, and an NTC thermistor at the receiving end is used to acquire the temperature of the receiving power device. Based on the temperature signal collected by the aforementioned sensor, the MCU controls the switching on and off of the charging MOSFET and transmits a power adjustment signal to the DC-DC power control circuit via the Bluetooth communication module to achieve temperature protection for the 24V lithium battery and power devices.

6. The wireless charger for electric hospital beds according to claim 1, characterized in that: The battery voltage monitoring module includes a voltage divider resistor branch. The MCU collects the 24V lithium battery voltage through this branch. When the voltage reaches 29.2V, it triggers a first-level warning. When it reaches 29.5V, it controls the main circuit MOSFET to disconnect. When the voltage is lower than 21.5V, it controls the main circuit MOSFET to disconnect. The current sampling resistor is electrically connected to the MCU. The MCU collects the charging circuit current through this resistor. When the current reaches 1.5 times the rated current, it triggers overcurrent protection. When it reaches 5 times the rated current, it controls the main circuit MOSFET to disconnect. When any of the above protection states are triggered, the MCU sends an alarm signal via the Bluetooth communication module.

7. The wireless charger for electric hospital beds according to claim 1, characterized in that: The Bluetooth communication module is electrically connected to the MCU via a signal line and has wireless signal transceiver hardware functions. It can establish a wireless communication link with the Bluetooth receiver module at the transmitting end and can also establish a wireless connection with external terminals to achieve signal interaction.

8. The wireless charger for electric hospital beds according to claim 1, characterized in that: Both the transmitter and receiver are equipped with PCBs. The PCBs adopt a symmetrical structure design and have mounting dimensions of 180mm×80mm×190mm. The PCBs are fixed to the back of the heat sink via threaded holes on the back plate, and the bottom of the PCBs is equipped with M3 mounting holes. The device has an energy transmission efficiency of >80%, an effective transmission distance of 28mm±10%, and an X / Y plane alignment tolerance range of ±20mm.

Images