Low Pass Filter design......

[Ahmed Nadeem]

Hey Everyone

I have to design a Low pass RC filter of 50Hz output frequency for 150 Watt sine wave inverter. Input peak Voltage of PWM is signal is 12 V. The carrier frequency of PWM is 8 kHz.


the picture of 50Hz sine PWM


Please help me about the components and values of passives used in fliter..

Thanks in advance

 

[barry]

1) You need to supply 12.5 Amps. (150/12)
2) You don't want to drop a lot of voltage across your resistor, so that means it has to be fairly small. How much drop can you tolerate?

Say you can tolerate 0.5V drop. That means the resistor has to be less than 0.04 ohms (.5/12.5). This doesn't sound too feasible, does it?

 

[kam1787]

RC? try LC, or a PI filter

 

[Ahmed Nadeem]

The reason is the the reqiured inductors are not available in my city :sad: So I have to use RC filter.. If you can help in desgning accurate value inductor of high wattage. then no problem, I will do that LC or pi filter..

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1) You need to supply 12.5 Amps. (150/12)
2) You don't want to drop a lot of voltage across your resistor, so that means it has to be fairly small. How much drop can you tolerate?

Say you can tolerate 0.5V drop. That means the resistor has to be less than 0.04 ohms (.5/12.5). This doesn't sound too feasible, does it?

Yeah of course it seems un feasible.. :sad: What you suggest..? As, the reqiured inductors of fixed values are not available in my city.. Whats the solution??

 

[kam1787]

Salvage from computer PSU.

http://www.wikihow.com/Measure-Inductance

http://www.instructables.com/answers/How-to-measure-inductance-of-a-coil-without-using-/

**broken link removed**

 

[barry]

The reason is the the reqiured inductors are not available in my city :sad: So I have to use RC filter.. If you can help in desgning accurate value inductor of high wattage. then no problem, I will do that LC or pi filter..

- - - Updated - - -



Yeah of course it seems un feasible.. :sad: What you suggest..? As, the reqiured inductors of fixed values are not available in my city.. Whats the solution??

Move to a city with more inductors.

Or make your own.