Current Transformer Feeding Switching Power Supplies

To make clear the behaviour of a current transformer used as a power supplier, experiments are made to investigate the relationship among the primary current, the secondary voltage and the secondary resistance. The obtained knowledge can be used as the design consideration for current transformer feeding switching power supplies.A switching power supply suitable for being fed by a current transformer is designed, which consists of a rectifier bridge, a MOSFET, a diode preventing current flow backward, a storage capacitor and a control circuit. The working process, the device stress and losses are analysed. The device selecting suggestions and the parameter design method are given. The design steps of the proposed power supply are also listed.A hybrid power supply of current transformer feeding and battery storage is proposed, which consists of a relay type switch, a rectifier bridge, a diode preventing current flow backward, a storage battery and a control circuit. The working process, the device stress and losses are analysed. The device selecting suggestions and the parameter design method are given. The design steps of the proposed power supply are proposed as well.The prototypes of above two novel power supplies are implanted, respectively, based on which, experiments are made for verification. The results of the experiments are in positive with the analysis and both of the two prototypes meet the design requirements.