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Seeking help to identify the following common mode choke. The best guess is it a part from Sumida Corporation.

enter image description here

This part is from a refrigerator.

Any of the following information is greatly appreciated

  • Datasheet
  • Manufacture
  • Specification

Based on research it was assumed that following part might have similar specification. Currently not too sure.

Following are results form searches.

JRE
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Mahendra Gunawardena
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    Where did it come from? – Tony Stewart EE75 Oct 06 '20 at 02:16
  • @TonyStewartSunnyskyguyEE75 cuui dorm room refrigerator – Mahendra Gunawardena Oct 06 '20 at 02:19
  • Yes looks like a 31 mH line choke. Why? Kemet source looks ok – Tony Stewart EE75 Oct 06 '20 at 02:22
  • @TonyStewartSunnyskyguyEE75 Trying to suppress noise from a wall wart. Randomly placed this part, and it appears to work. Thus trying to work backward to confirm the solution. – Mahendra Gunawardena Oct 06 '20 at 02:27
  • Wall supply is regulated? Causing noise ? To what? Yes a Pi filter or CLC with CM L choke will attenuate SMPS noise, but it ought to have one, maybe too cheap to... – Tony Stewart EE75 Oct 06 '20 at 02:28
  • @TonyStewartSunnyskyguyEE75, The Kemet part we used is 5.95 µH. Looks like it is too small. – Mahendra Gunawardena Oct 06 '20 at 02:30
  • Yes uH is too low impedance for 30kHz region noise use load R/L = 2pi omega and C impedance shunt with plastic line rated caps to compute impedance ratio attenuation... +1nF – Tony Stewart EE75 Oct 06 '20 at 02:31
  • @TonyStewartSunnyskyguyEE75, Curious, how did you determine it is 30kHz noise load. Also can you help me understand why "plastic line rated capacitors". Also I have ordered 10mH and 2.2 mH inductors. – Mahendra Gunawardena Oct 06 '20 at 10:50
  • Line caps are for L-L or L-G as X or Y rated for transient safety Poly type caps. Just a guestimate on SMPS f commonly used above audio range. – Tony Stewart EE75 Oct 06 '20 at 16:20
  • 2 way line filters for SMPS to block line noise in and switcher noise out use a CM choke to make CM rejection of carrier and differential mode with cap So we call it a CLC CM Pi filter common to most SMPS line inputs. XY info https://electronics.stackexchange.com/questions/333029/what-is-an-xy-rated-safety-capacitor-exactly The the CM choke or Balun equalizes high impedance on L-N then the caps are chosen to shunt at low Z(f) by impedance ratio yet minimize leakage to gnd < 0.5mA at 50,60 Hz – Tony Stewart EE75 Oct 06 '20 at 16:58
  • This shows it better for both CM and DM noise rejection https://electronics.stackexchange.com/questions/201302/switch-mode-power-supply-and-emi-on-input-power-line-filtering except this is a DC source with large caps , so AC source uses 1~4nF for same benefits of attenuation of differential and common mode noise , read Murata link p30 – Tony Stewart EE75 Oct 06 '20 at 17:04
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    @TonyStewartSunnyskyguyEE75 thank you for you insights. – Mahendra Gunawardena Oct 06 '20 at 19:08

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