Author Topic: Nikon charger MH-24 transformer replacement  (Read 1057 times)

0 Members and 1 Guest are viewing this topic.

Offline sdancer75Topic starter

  • Regular Contributor
  • *
  • Posts: 235
  • Country: gr
Nikon charger MH-24 transformer replacement
« on: June 29, 2022, 02:15:49 pm »
Hi


Is there any replacement part for the transformer (mark code OR20A153)  shown at the attached pictures?The part is from a Nikon charger MH-24. Anyway, how can I possibly know if the two parts are matched? ie, the same primary and secondary resistance?

PS : After a fall, the lead conductor is torn apart from it's pin base. I tried to find the edge to reconnect it but I couldn't despite my efforts with my microscope. Anyway, I am thinking to replace it but I don't know the type.

Can someone help with this?
 

Offline Uunoctium

  • Regular Contributor
  • *
  • Posts: 111
  • Country: de
Re: Nikon charger MH-24 transformer replacement
« Reply #1 on: June 29, 2022, 03:53:40 pm »
looks very close to Eaton ECMT-R Common Mode Chokes
Example from Mouser:
https://www.mouser.de/ProductDetail/Bussmann-Eaton/ECMT1V2429S-5R0-R?qs=TCDPyi3sCW1elWL00jyiFA%3D%3D
 
The following users thanked this post: sdancer75

Online Zoli

  • Frequent Contributor
  • **
  • Posts: 498
  • Country: ca
  • Grumpy old men
Re: Nikon charger MH-24 transformer replacement
« Reply #2 on: June 30, 2022, 05:19:10 am »
Hi


Is there any replacement part for the transformer (mark code OR20A153)  shown at the attached pictures?The part is from a Nikon charger MH-24. Anyway, how can I possibly know if the two parts are matched? ie, the same primary and secondary resistance?

PS : After a fall, the lead conductor is torn apart from it's pin base. I tried to find the edge to reconnect it but I couldn't despite my efforts with my microscope. Anyway, I am thinking to replace it but I don't know the type.

Can someone help with this?
Looks like is the 15mH one(153 printed on the top).
 
The following users thanked this post: sdancer75

Online mariush

  • Super Contributor
  • ***
  • Posts: 5006
  • Country: ro
  • .
Re: Nikon charger MH-24 transformer replacement
« Reply #3 on: June 30, 2022, 06:09:54 am »
If it's a common mode choke, you could just replace it with two jumper wires. The part is there to filter/reduce the "noise" sent back into the AC grid.  Without it, maybe an AM radio would not work as well, or something like that, but otherwise it would be perfectly safe.

If you look at the traces on the circuit board it would be something like this 

---- ac ~ ---- ~                        + ------ +----- +            + -----  +------ +
                        bridge rectifier         cap (c1)      choke         cap (c2)         DC-DC converter chip (U2)
---- ac ~ ---- ~                        - ------  -  ----  -            - ------  - ------ -

Between the two + of the choke you'd have a coil , and between the two minuses of the choke you'd have a coil  ... so you could replace with two wires , one between the two + of the choke, one between the two - of the choke
« Last Edit: June 30, 2022, 06:11:47 am by mariush »
 
The following users thanked this post: sdancer75

Offline sdancer75Topic starter

  • Regular Contributor
  • *
  • Posts: 235
  • Country: gr
Re: Nikon charger MH-24 transformer replacement
« Reply #4 on: June 30, 2022, 07:25:25 am »
Yes, my mistake, it is an inductor. I measured about 10mH. The rated current of the inductor should be output current of the charger?

Thanks
 

Offline sdancer75Topic starter

  • Regular Contributor
  • *
  • Posts: 235
  • Country: gr
Re: Nikon charger MH-24 transformer replacement
« Reply #5 on: June 30, 2022, 07:26:18 am »
 

Offline sdancer75Topic starter

  • Regular Contributor
  • *
  • Posts: 235
  • Country: gr
Re: Nikon charger MH-24 transformer replacement
« Reply #6 on: June 30, 2022, 07:29:59 am »
If it's a common mode choke, you could just replace it with two jumper wires. The part is there to filter/reduce the "noise" sent back into the AC grid.  Without it, maybe an AM radio would not work as well, or something like that, but otherwise it would be perfectly safe.

If you look at the traces on the circuit board it would be something like this 

---- ac ~ ---- ~                        + ------ +----- +            + -----  +------ +
                        bridge rectifier         cap (c1)      choke         cap (c2)         DC-DC converter chip (U2)
---- ac ~ ---- ~                        - ------  -  ----  -            - ------  - ------ -

Between the two + of the choke you'd have a coil , and between the two minuses of the choke you'd have a coil  ... so you could replace with two wires , one between the two + of the choke, one between the two - of the choke

Yes, I found out that it is indeed an EMI filter choke. I will try to replace it with a 10mH/1.2A choke but if I don't find one I will short the pins.

Thanks,
 

Offline abdulbadii

  • Frequent Contributor
  • **
  • !
  • Posts: 350
  • Country: us
Re: Nikon charger MH-24 transformer replacement
« Reply #7 on: June 30, 2022, 09:33:53 am »
Not transformer, it's common or differential choke, Imo need a schematic
 
The following users thanked this post: sdancer75

Online tunk

  • Frequent Contributor
  • **
  • Posts: 976
  • Country: no
Re: Nikon charger MH-24 transformer replacement
« Reply #8 on: June 30, 2022, 10:13:17 am »
The rated current of the inductor should be output current of the charger?

No expert, but this is on the high voltage side, so I don't think it needs to.
Again no expert, maybe something like this (0.7=70% efficency):
8.4V/230V * 1.2A / 0.7 = 0.063A
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf