Multi-Output DC Power Supply Using Push-Pull Converter Powered from PV Modules

This paper presents designing and making a multi-output DC power supply (MOPS) feeding from the PV modules. The MOPS is based on a push-pull converter topology that provides four output channels of 12-V 1-A each and will be used to supply the control circuit of the six-step power inverter that drives the 3-phase squirrel cage induction motor of the centrifugal pump. This MOPS, along with the inverter, the induction motor, and other circuits, are the main parts that construct the battery-less solar water pumping system. The push-pull converter is controlled by the PWM controller SG3525 and operated as an open-loop controller with switching frequency of 20 kHz. Since it works without a feedback element, the linear voltage regulator LM7812 has been placed on each output channel of the push-pull converter to obtain regulated 12-V voltage. The functional test was conducted on the MOPS, and the result showed that the power supply could maintain regulated voltage at each output channel from no-load to 100-ohm load conditions.