Consucted Emission failure

[Analog2008]

Hello,
We are workingon aa design that has a DC/DC converter that converts 120V AC to 12V DC with 12x8 VA power.
We fail the class A in Conducted Emission IEC EMC requirments, we are looking for a consultant to help us.

Please help me to resolv this ASAP.

Thanks,

 

[Speakerguy]

Please send me a private message. I have experience in power conversion and EMC.

 

[audioguru]

You forgot to attach your schematic so we don't have a clue about how it works.
It might be a switching converter that radiates harmonics or sends harmonics into the 120VAC power line.
Frequently the power cord has a hinged ferrite core attached which forms a filter without cutting the cord.

 

[Ubergeek63]

Hello,
We are workingon aa design that has a DC/DC converter that converts 120V AC to 12V DC with 12x8 VA power.
We fail the class A in Conducted Emission IEC EMC requirments, we are looking for a consultant to help us.

Please help me to resolv this ASAP.

Thanks,

you mean 100W. VA is a transformer spec and should be halved to get to a safe DC output level since the capacitor takes high currents.

you could start with a good common mode choke and capacitors. reducing the slope on the power switch helps but increases the power losses.

Dan