EPC Introduces A4WP Compliant Wireless Power Transfer Demo Kit
GaN FET evaluation kit for 6.78MHz, 35W wireless power transfer systems
Efficient Power Conversion Corporation (EPC) has announced the availability of a complete demonstration wireless power transfer kit. The 40V (EPC9111) or 100V (EPC9112) wireless kits comprise a source (or amplifier) board, a Class 3 A4WP compliant source (or transmit) coil, and a Category 3 A4WP compliant device (or receiving) board including coil
The system is capable of delivering up to 35W into a DC load while operating at 6.78MHz (the lowest ISM band). The kit simplifies the evaluation process of using eGaN FETs for wireless power transfer. The EPC9111 and EPC9112 utilise the high frequency switching capability of EPC gallium nitride transistors to facilitate wireless power systems with greater than 75 percent efficiency.
Wireless energy transfer systems need high efficiency, low profile, robustness to changing operating conditions and, in some cases, low weight. This means designs should be efficient and able to operate at high switching speeds without a bulky heatsink. Furthermore the design must be able to operate over a wide range of coupling and load variations. The fast switching capability of eGaN FETs, says EPC, is ideal for highly resonant power transfer applications.
The popularity of highly resonant wireless power transfer is increasing rapidly, particularly for applications targeting portable device charging. The end applications are varied and evolving quickly from mobile device charging, to life-extending medical implementations, to safety-critical hazardous environments.
The source board is a A4WP compliant, Zero Voltage Switching (ZVS), Class-D amplifier featuring either the 40V EPC2014 (EPC9111) or the 100 V EPC2007 (EPC9112) eGaN FET. It is configured in an optional half-bridge topology (for single-ended configuration) or default full-bridge topology (for differential configuration), and include the gate driver(s) and oscillator that ensure operation of the system at 6.78MHz. These amplifier boards are available separately as EPC9506 and EPC9507 for evaluation in existing customer systems.
The source coil, as well as the device coil, are Rezence (A4WP) compliant and have been pre-tuned to operate at 6.78MHz. The device board includes a high frequency Schottky diode based full-bridge rectifier and output filter to deliver a filtered unregulated DC voltage. The device board comes equipped with two LED's, one to indicate the power is being received and a second LED, which indicates that the output voltage has reached the maximum and is above 37 V.The device board can also be configured as a half-bridge rectifier that allows for double output voltage operation.
