your vidoes are very useful. They explain important concepts very clearly. Thanks for videos. I have a question on common mode noise current (capacitive) If Mosfet heatsink is not tied to earth, we do not have common mode current . Is it right? especially in small power ratings it is possibble to use an electrically floating heatsink (not tied to chasis of the device). In such a power supply do we need common mode mode filter?
Hi Serdar, most likely you would need a common mode inductor. Even thou the heatsink is floating, there are stray capacitance that couple the electric field to the chassis. To be on the conservative side, I would implement one. Robert Bolanos
Hi Aneesh, Sorry for the delay in answering. If you dont have a earth return, the noise will seek and return to the power supply's return and if both the hot and the return have different impedance, it will show up as addition noise in the differential mode. Hope this makes sense
Hi. What is the primary reason that the minus of the supply is connected to the chassis? Second, if it's not connected I presume there will still be a common mode current but this time it will flow through two parasitic capacitors where the other is from the earth to the (-) wire? You have a small error at the end, you say common mode capacitor, it's actually diff mode. Another thing, if impedances in the line & neutral are not the same than the current signal won't be identical, right? Thanks!
Hello sir please help me sir one transfarmer 3 wire 24 swg turn 8 secondary 00.4 mh,1 wire 28 swg turn 128 core E ,C 40.24 No gap core PRIMARY 43.mh but sir i use EC 40 CORE gap so sir setting the my transfarmer thank you
Hi Tite Man, I agree, I wish I had done a better job of arranging things. I have been instead trying to concentrate on the technical content. But arranging things would defiantly make it better. Thanks for the feedback Tite Man! Robert
Thank you for such a good video, looking forward to part 12 how to design the filter!
thanks a lot, it clearly helps me understand CM!
thanks so much this video help me a lot
your vidoes are very useful. They explain important concepts very clearly. Thanks for videos.
I have a question on common mode noise current (capacitive)
If Mosfet heatsink is not tied to earth, we do not have common mode current . Is it right?
especially in small power ratings it is possibble to use an electrically floating heatsink (not tied to chasis of the device). In such a power supply do we need common mode mode filter?
Hi Serdar, most likely you would need a common mode inductor. Even thou the heatsink is floating, there are stray capacitance that couple the electric field to the chassis. To be on the conservative side, I would implement one. Robert Bolanos
What will happen if the earth is not connected to return?. Common mode will not get a path, so will Common mode noise disappear?
Hi Aneesh, Sorry for the delay in answering. If you dont have a earth return, the noise will seek and return to the power supply's return and if both the hot and the return have different impedance, it will show up as addition noise in the differential mode. Hope this makes sense
Hi. What is the primary reason that the minus of the supply is connected to the chassis? Second, if it's not connected I presume there will still be a common mode current but this time it will flow through two parasitic capacitors where the other is from the earth to the (-) wire? You have a small error at the end, you say common mode capacitor, it's actually diff mode. Another thing, if impedances in the line & neutral are not the same than the current signal won't be identical, right? Thanks!
Thank you a lot it was useful, but I was wandering How can I get PWM in real world?
How about when the mosfet is already plastic tabs. Does it really mean no more cm noise at all?..
Thatcapacitance is always there. It may be lower. Keep in mind that all insulators have a dielectric constant
So yes it will have capacitances.
Hello sir please help me sir one transfarmer 3 wire 24 swg turn 8 secondary 00.4 mh,1 wire 28 swg turn 128 core E ,C 40.24 No gap core PRIMARY 43.mh but sir i use EC 40 CORE gap so sir setting the my transfarmer thank you
your tutorial is fantastic but one thing is that your videos are not properly arranged
Hi Tite Man, I agree, I wish I had done a better job of arranging things. I have been instead trying to concentrate on the technical content. But arranging things would defiantly make it better. Thanks for the feedback Tite Man! Robert