Keywords: flyback converters, single-capacitor snubbers, power electronics, auto-tuning, fan speed systems, rotational speed, temperature, fan bearings, wear, conversion efficiency
Flyback converter using single-capacitor snubber for auto-tuning fan speed system
This paper presents flyback converter combined with single-capacitor turn-off snubber for auto-tuning fan speed system. The proposed system can automatically adjust rotational speed of fan, depending on the temperature in the chassis of the equipment. Its control algorithm is realised by a PWM IC which, by taking into account the converter output voltage and chassis temperature, will regulate the output voltage of the converter. With this approach, the wear and tear of the bearing of fan can be reduced and the circuit structure, compared with the conventional two stage driving circuit, can be simplified. Therefore, the proposed system can raise conversion efficiency, reduce component count, weight and size. Moreover, in order to further increase conversion efficiency of the proposed system, a single-capacitor turn-off snubber is adopted to reduce switching loss at turn off transition, Finally, a prototype under output voltage varied from 5 V-12 V and maximum output power of 200 W has been implemented to prove the feasibility of the proposed auto-tuning fan speed system.