Michael Kurniawan 2018123456 University of Cincinnati Midterm Exam Power Electronics Technology Question 1. Complete the circuit below with the appropriate calculations and component values, when the voltage is applied to the load. a. Make a report containing, theoretical basis, calculations, analysis and conclusions b. Simulate with PSIM; c. Deliver the measurement results with Oscilloscope Psim shown in the following table:  At no load condition (RL)  At full load according to the planned current MEASUREMENT VOLTAGE (V) VOLTAGE (V) POINT WITHOUT LOAD FULL LOAD A-B VC TR1 VC TR2 VZD VB TR2 V LED VRL Rated full load current …… WAVEFORM Answer : 1. Figure 1. Picture of the simulation circuit at PSIM A. Introduction to Theory A power supply is an electronic device that is useful as a power source so that other devices can work. The power supply has a circuit that converts AC electric current into DC. DC Power Supply or Power Supply is also often known as “Adapter”. The power supply has 4 main parts in order to produce a stable DC current. The four parts include: a. Transformer: the main component in making a power supply circuit that functions to change the voltage, namely increasing and decreasing the voltage. Based on the voltage issued, it is divided into 2, namely: Step Up Transformers and Step Down Transformers. In making the power supply, the transformer used is a step down transformer which functions to reduce the 220 VAC voltage to a smaller voltage (5V, 9V, 12V) or as needed. The transformer works based on the principle of electromagnetic induction which consists of a primary winding and a secondary winding. The primary winding is the input of the tarfo and the secondary winding as the output. After being lowered by the Step-down transformer, the resulting voltage is still in the form of alternating current (AC) which will then be entered into the rectifier circuit. b. Rectifier: The role of the rectifier in the power supply circuit is to convert AC voltage into DC voltage. Rectifiers usually consist of diodes. In the rectifier circuit there are 2 types, namely “Half Wave Rectifier” which consists of 1 diode component and “Full Wave Rectifier” which consists of 2 or 4 diode components. c. Filter: a part consisting of a capacitor that serves to flatten the DC current signal coming from the rectifier. As a result of installing a capacitor as a filter, the DC voltage will become smoother and cleaner, so that the wave that comes out is the output wave VD. d. Regulator that functions as a voltage stabilizer: a part consisting of a Zener diode, transistor, IC or a combination of the three components. This component functions as a stabilizer and regulator of the DC voltage coming from the filter circuit, so as not to be affected by the load voltage. B. Calculation Given : a. Sine voltage source of 220 volts and 50 Hz b. At the transformer the ratio of np / ns = 1/1 c. Using ideal bridge diodes d. C = 4.7 uF e. R1 = R2 = R3 = R4 = R5 = 12 ohms f. RL = 30 ohms Asked : a. Vout wthout RL b. Vout c. VIN Answer a. Vout without RL = 27.315 volts Figure 2. Vout measurement results without RL using PSIM b. Vout = 27.314 volts Figure 3. Vout measurement results using PSIM c. Vin = 220 volts Figure 4. Vin Measurement Results using PSIM C. Analysis The initial voltage entering is 220 volts, after passing through the transformer and the ideal rectifier diode the voltage decreases to approximately 30 volts, this proves that the function of the transformer component is to change the voltage, which is to reduce the voltage from the initial voltage, and rectifier diodes that can rectify AC currents into DC aris, and regulators that make DC teganagan stable and even. D. Conclusion The components of the power supply consist of : a. Transformer, is a component that functions to change the voltage, which is to reduce the voltage from the power source, in this case the 220 AC voltage is reduced to a smaller AC current. b. Diode, serves to rectify AC current into DC current, by blocking half a half wave of AC current. c. Capacitor, serves to filter the unstable DC voltage and make it flat and stable. d. IC Voltage Regulator, serves to convert DC voltage into a stable voltage and is ready to be used by electronic devices. 2. Measurement results with Oscilloscope Psim Rated full load current = 1.845 Amperes