Transcranial magnetic stimulator is a high-voltage, high-current pulse generator used to generate time-varying magnetic fields to stimulate the brain. In the controllable transcranial magnetic stimulator with H-bridge topology, fully-controlled switching devices are generally applied to replace half-controlled switches. However, in such pulse power application, the energy in conventional RCD buffer for fully-controlled switches will cause ringing phenomenon, heating and high energy loss, reducing the stimulation effect, the reliability and the efficiency of the stimulator. Aiming at this special pulse power scenario, a specially designed flyback converter is innovatively introduced for the active energy feedback of a new lossless buffer of the stimulator to solve the above problems. The design consideration and implementation of the targeted flyback converter are presented in detail, with special attention paid to the operation mode selection and the magnetic core design. The feasibility of the proposed design is confirmed by simulation, showing that the designed flyback converter is able to meet all the requirements with an efficiency of up to 85.4%, providing some ideas for the application and special design considerations of mature topology for special requirements in rare scenarios.

flyback converter;pulse power;transcranial magnetic stimulaiton;lossless buffer circuit;active energy feedback