Summary of Wireless Transmitter System
This wireless charging project utilizes magnetic induction to transmit power between separated primary and secondary coils. The system employs the WCT1000 controller with Freescale touch sensing technology to detect devices, adjust frequency for power transfer, and ensure safety via over-voltage protection and Foreign Object Detection (FOD). It achieves stable closed-loop control by regulating voltage at the receiver and communicating operational data back to the transmitter.
Parts used in Wireless Charging System:
- Magnetic induction transformer (primary and secondary coils)
- WCT1000 wireless power transmitter controller
- Freescale touch sensing technology
- Digital demodulation module
- Capacitive touch sensor
- Additional electrode touch pad
- Communication link for protocol transmission
Summary
This wireless project is a power transmission system, it works on the principle of magnetic induction. This Wireless Charging system works as the digital switched mode power supply with the transformer, which is separated into two parts: The transformer primary coil is on the transmitter, working as the transmitter coil, and the transformer secondary coil is on the receiver side as the receiver coil. This system works based on magnetic induction, the better coupling between the transmitter coil and receiver coil gain, the better system efficiency. So the receiver coil should be closely and center aligned with the transmitter coil as possible. After the receiver coil receives the power from the transmitter coil by magnetic field, it regulates the received voltage to power the load, and send its operational information to transmitter according to specific protocol by the communication link. Then the system can achieve the closed-loop control, and power the load stably and wirelessly.
The WCT1000 is a wireless power transmitter controller, it is an intelligent device that can work with Freescale touch sensing technology to detect a mobile device for charging while gaining super low standby power. Once the mobile device is detected, the WCT1000 controls the power transfer by adjusting operation frequency of power stage according to message packets sent by mobile device. The WCT1000 includes digital demodulation module to reduce external components, over-voltage/current/ temperature protection and Foreign Object Detection (FOD) method to protect from overheating by misplaced metallic foreign objects. It also handles any abnormal condition and operational status, and provides comprehensive indicator outputs for robust system design. Capacitive touch sensor is selected in this design, and an additional electrode touch pad is designed to sense the placement of mobile device. When the mobile device is put on the transmitter coil, Touch Sensor IC will detect the capacitance change on the pad, and then trigger an interrupt request signal to wake up WCT1000.
For more detail: Wireless Transmitter System
- How does this wireless charging system work?
It works on the principle of magnetic induction where the primary coil transmits power to the secondary coil. - What is required for better system efficiency?
The receiver coil should be closely and center aligned with the transmitter coil as possible. - Can the WCT1000 detect a mobile device automatically?
Yes, it uses Freescale touch sensing technology to detect a mobile device while gaining super low standby power. - Does the system protect against overheating from foreign objects?
Yes, it includes a Foreign Object Detection method to protect from overheating by misplaced metallic foreign objects. - What triggers the WCT1000 to wake up?
An interrupt request signal triggered when the Touch Sensor IC detects a capacitance change on the pad. - How is the received voltage managed at the receiver side?
The receiver regulates the received voltage to power the load and sends operational information to the transmitter. - What role does the digital demodulation module play?
It reduces the number of external components needed in the design. - Can the system achieve closed-loop control?
Yes, by sending operational information according to a specific protocol, the system powers the load stably and wirelessly.
