Author Topic: Y caps better directly across transformer in offline flyback SMPS? (Read 1102 times)

Faringdon · « **on:** July 17, 2021, 04:08:43 pm »

Page 4 of the Mornsun LS15-13B12 power module (Offline flyback, 12vout, 15w out) shows a Y cap from primary ground to secondary ground. This is obviously for common mode filtration. But wouldnt it be better if it was actually fitted on the Mornsun PCB and placed right across the actual isolation barrier, immediately next to it?

Mornsun offline power module
https://www.mornsun-power.com/html/pdf/LS15-13B12SS-F.html

voltsandjolts · « **Reply #1 on:** July 17, 2021, 04:13:25 pm »

Please stop. Please.

jonpaul · « **Reply #2 on:** July 19, 2021, 01:28:12 pm »

No reason, the module supplier is showing various safety and EMI components external to the module.

Diffreent applications will demand different X, Y caps, fuses etc eg Japan/EU/USA or application areas, eg medical/broadcast/consumer/industrial.

Jon

Faringdon · « **Reply #3 on:** July 19, 2021, 04:12:39 pm »

Thanks, though you would agree, that Y caps across the isolation barrier need to be as near the transformer as possible?

Gyro · « **Reply #4 on:** July 19, 2021, 09:42:34 pm »

Y caps are far more accessible in through-hole. You should have noticed that the Mornsun module is completely smt.


EEVblog Main Site	EEVblog on Youtube	EEVblog on Twitter	EEVblog on Facebook	EEVblog on Odysee

EEVblog Electronics Community Forum

Author Topic: Y caps better directly across transformer in offline flyback SMPS? (Read 1102 times)

Faringdon

Y caps better directly across transformer in offline flyback SMPS?

voltsandjolts

Re: Y caps better directly across transformer in offline flyback SMPS?

jonpaul

Re: Y caps better directly across transformer in offline flyback SMPS?

Faringdon

Re: Y caps better directly across transformer in offline flyback SMPS?

Gyro

Re: Y caps better directly across transformer in offline flyback SMPS?

Share me