Practical, Programmable and Accurate Hybrid DC-Power Supply
Mohammed O. Alsumady, Yazan K. Alturk, Ibrahim O. Jaber and Reema Hijjawi
DC Power supplies are extremely important in designing and manufacturing electrical and electronic appliances and devices. In this paper practical, programmable, and accurate hybrid power supply was designed, manufactured and tested. The output voltage ranges from 0V up to 20V, with 0.1V programmable resolution and tuning capability of 5 millivolts. Reverse bias and output polarity reversal protections are included in this modified design. Output current ranges from 0A up to 1A with 25mA programmable resolution. The introduced power supply has a modified new techniques of controlling output voltage and current; Linear voltage regulator LT3080 is used due to its control simplicity and a 12-bit DAC with AVR Microcontroller are used to set the output voltage and current accurately. Current sensing amplifier was used to measure the drawn current. An isolated flyback supply is recruited to power the circuit. Preregulator tracking technique is applied to keep the power dissipation down to the minimum by controlling the input/output voltage fluctuations across the linear regulator.
Keywords: Hybrid power supply, digital to analog converter (DAC), switching mode power supply (SMPS), electro magnetic interference (EMI), tracking pre-regulator, digital potentiometer, current limiter, SPI protocol, PCB