Paper Synthesis on

ExperimentReport on Uninterruptable Variable DC Power Supply (2V-12V)

Experiment Report onUNINTERUPTABLE VARIABLE DC power supply (2V-12V)BSEE 3-2September 2, 2014

Project SummaryThe study is about assembling an uninterruptable power supply (UPS) which is variable from 2-volts to 12 V. The UPS had its built-in 12-volts, 7Ah back-up battery with an analog volt-meter.

Figure 1Uninterruptable Variable DC Power Supply

IntroductionAn uninterruptable power supply is an electrical apparatus that provides emergency power when the input source fail. The UPS gives an output power and simultaneously charges the back-up battery when the power source is up. This electrical apparatus is prevents the damage that can be caused by a sudden power disruption.

PurposeThe study intends to discover the principles behind an uninterruptable power supply and also how the electronic components in it works. This is study was done also to challenge the skills and knowledge of the researcher in analyzing and connecting electronic components in the circuit. This study is also a great help in preventing data loss on devices, such as computers, and problems caused by sudden power interruption.

ScopeThe study limits itself in assembling an uninterruptable power supply which is variable to 2 V to 12 V DC. It is not intended in providing power for desktop and laptop computers or even charging a cellphone and other electronic gadgets for it may give up too much current that the battery of those devices cannot manage to handle. But instead, this study is for research and experiment purposes which needs a DC supply of 2 V to 12 V. The output voltage seems to be above or below the supply voltage.

Discussion

Figure 2 UPS Schematic Diagram

MethodologyThe project before being done have gone series of steps and have used different components.

Table 1| Components used in the experimentQUANTITYMATERIALS

5 pcs1N4007

1 pc2200F 25V Electrolytic Capacitor

1 pc220 Resitor

1 pc1k Resistor

1 pcYellow LED Light

2 pc143K Ceramic Capacitor

1 pc10F electrolytic Capacitos

1 pcL7805CV Voltage Ragulator

1 pc10K Potentiometer

1 pc Resettable Circuit Breaker

1 pc12V 7AH Battery

1 pc12V-0V-12V Center Tap Transformer

1 pc0V-20V DC Voltmeter

1 pcUniversal Printed Circuit Board

1 pcChassis

ProcedureThe design had undergone series of process. 1. Collect the components needed2. Test the components3. Assemble the circuit on the breadboard according to the schematic

Figure 3 UPS on the breadboard

4. Place the circuit on the universal printed circuit board5. Check the connections of each of the components6. Solder the components on the universal PCB7. Connect the jumper wires to the output terminals8. Connect jumper wires to the potentiometer9. Connect to the battery10. Test the voltage output

Figure 4 UPS supplied by the back-up batteryFigure 5UPS supplied by the back-up battery11. Connect to the center tap transformer12. Connect to the power source13. Test the output voltage

Figure 6 UPS supplied by AC power source

Figure 7UPS supplied by AC power source14. Assemble in the chassis

Test and EvaluationBased on the series of sampling and testing of the uninterruptable power supply, it gives the values:Table 2| Sampling and testing data sheetVoltage Output(Connected to Power Source)Digital Multi-meter(Interrupted Power)

Multitester(UPS set to the lowest voltage)2.282 V2.232 V

Multitester (UPS set to the highest voltage)9.46 V8.14 V

References100nF Capacitor, (September 1, 2014), Retrieve from: [http://www.usefulcomponents.com/main_contents/projects/choccy_block_trf_radio/bom_pages/bom_cap_ceramic_100n.html].IC7805 Capacitor, (August 31, 2014), Retrieve from:[http://electronics.stackexchange.com/questions/8121/capacitor-sizes-for-7805-regulator].IC7805 Pin-out, (August 31, 2014), Retrieve from:[http://en.wikipedia.org/wiki/Uninterruptible_power_supply].Simple UPS Schematic Diagram, (August 25, 2014), Retrieve from:[http://www.circuitstoday.com/simple-ups-construction].Uninterruptable Power Supply, (September 1, 2014), Retrieve from: [http://en.wikipedia.org/wiki/Uninterruptible_power_supply].Page 1 of 2Page 5 of 6