Analysis And Design Of Loosely Coupled Power Supply Based On The Flyback Circuit

The design the loose coupling power supply of this topic is based on of the flyback circuit, which is based on the contactless power supply and transfer technology. Wireless power supply technology makes the transmission of electrical energy to get rid of the traditional electrical connection. Wireless power supply technology in a specific field has great application value, with the further research of non-contact power transmission, power wireless transmission technology from the aspects of efficiency, reliability and safety have greater progress, make application of the electric power more wide and flexible. At present, with the application of wireless power supply of electric vehicles, smart phone, wireless power supply technology is moving toward the public field of vision, wireless power supply technology has great research value and significance.In terms of circuit designation and control method, this paper on foundation of the flyback circuit, changing the flyback transformer to a loose coupling transformer, in order to adapt to the loosely coupled transformer leakage inductance, the flyback circuit is improved to protect the switch tube. We analyze this modified circuit by decoupling equivalent model, and divide the circuit into four working states, solve it in time-domain and draw the theory waveform respectively. By analyzing the relationship that the circuit frequency changes with the coupling coefficient and switch-on time of the MOSFET, as well as analyzing the relationship between output power and switch-on time of the MOSFET, we propose a kind of power control strategy-switch on the MOSFET when the current is zero-crossing and control the switch-on time by the average current., can make the circuit in the resonant and automatic feedback regulating the stability of output power.The actual design and implementation of the circuit, using the differential circuit to produce the synchronous pulse to synchronous the control chip, the use of the integrated circuit is to get the average of the changing current. Then, the parameters of the key components of the circuit are calculated to provide theoretical guidance for the selection of the device, and the steps of the selection of the loose coupling transformer are introduced in detail.Finally in this paper we verify the effectiveness of this designation with the experimental results, through the actual circuit debug waveform analysis, to verify the circuit can realize wireless power transmission and power control strategy of this circuit can realize very well that, on the circumstance of circuit various coupling coefficient of the loose coupling transformer, this circuit has a steady power output. The power control strategy of this circuit can be very good to achieve the circuit under different coupling coefficient of the loosely coupled transformer, the power of the stable output, can become the technical basis of wireless LED table lamp.