Dear forum members, Sir, Iam having Lenovo PC, It is useing 180W SMPS, it is built useing two 470 micro farad,400 V capacitors in rectifier circuit,.Each capacitor has single pf capacitor in parallel. as shown in fig. Both pf capacitor has burnt and unable to find it`s value. Please any one can tell how much the value must be..
All i can think of is having a specifically winded transformer that has two secondary coils that gives 130 volts AC each. Or a center tap transformer that takes 220V for the primary and a 130-0-130V as secondary. Then rectify the output and have a regulator to convert it to DC. For the amperage that’s a pretty high rating, you will need a large gauged wire for this project.
You can use 0.1 mfd ceramic 400v or 600v cap in this place. But before replacing capacitors make sure the main switching transistor,zener diode is short or any other component is open or gone high value (resistors) carry out a cold check of the components ie (mains power disconnected condition ) after replacing the faulty components switch on the power supply with out connecting both the 470 mfd and 0.1 cap if the power supply voltage is as per your requirement and below the voltage rating of the capacitors then you can safely connect the caps after disconnecting the mains power. pl review my rating.
The discussion focuses on designing a switch mode power supply (SMPS) with a 220V AC input and a split ±130V DC output at 10A. Key design considerations include using a transformer with either two secondary coils each providing 130V AC or a center-tapped transformer with a 130-0-130V secondary winding. The AC output is then rectified and regulated to achieve the desired DC voltage and current. For high current output (10A), appropriate wire gauge and robust components are necessary. Regarding component specifics, in a related SMPS design using 180W power, two 470µF 400V electrolytic capacitors are used in the rectifier stage, each paralleled with a small-value ceramic capacitor (around 0.1µF, 400V or 600V) for filtering. Before replacing capacitors, it is advised to check other components such as switching transistors, zener diodes, and resistors for faults. The design complexity is manageable if the positive 130V DC output design is understood, and regulation requirements for both positive and negative outputs are clarified. Summary generated by the language model.
