Do i need this zener diode?

Discussion in 'General Electronics Chat' started by Paulnoviceb, Jan 23, 2016.

  1. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    Hi, sorry real novice here. Wondered if I could seek some advice. Just purchased a new 12v capstan motor to fix a cassette deck, an alternative brand of motor as the one I needed is no longer available. I have the task of de-soldering old motor connections and soldering to new motor but old motor has what I'm told is possibly a zener diode (I sent pic to the supplier of old motor). The supplier says not to bother putting this diode on the new motor. Does that sound plausible? There are holes in board that would accommodate it, but not sure what to do. The old motor was the original for this cassette deck, complete with this diode whatever it maybe (although having Googled zener diodes, I'm reasonably happy that it is a zener diode).
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,534
    2,369
    I doubt a zener in any case you need to know the zener voltage of it.
    Most likely a BEMF diode if it is across the motor.
    Max.
     
    Dr.killjoy likes this.
  3. Dr.killjoy

    Well-Known Member

    Apr 28, 2013
    1,190
    156
  4. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
     
  5. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    This is the component (hopefully I've attached a pic here).

    Paulnoviceb_1453578893222_essential.jpg

    Moderators note : reduced the picture to its essentials, we do not need the very large white space
     
    Last edited by a moderator: Jan 23, 2016
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,534
    2,369
    Is it shot? Can you resuse it?
    Max.
     
  7. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,982
    744
  8. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    Does that sound like something I can disregard with this new motor as advised?
     
  9. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,534
    2,369
    Maybe the supplier meant it was not needed as if the motor is switch off when turning, the generated voltage is reverse biasing the diode anyway?
    Max.
     
  10. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    He advised not to fit the "zener diode" so I'm a bit dubious of his advice in light of what you guys n gals have certified it as. A Back Emf diode you say, could it be possible I don't need this on an alternative motor to my existing, or is it not a crucial component to the workings in general maybe? Or could it be detrimental if I don't fit for that matter?
     
  11. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,534
    2,369
    Motors are pretty rugged devices, although diodes across them are usually meant for the circuit it is being controlled by, what is the technology of the motor? DC brushed or?
    Max.
     
  12. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    I'm guessing Yes dC brushed, but I know only little of motors sorry. It's a Mabuchi EG-530AD-2B. It's to replace a Matshushita MMI-6S2LK. It's a 3 head Teac tape deck I've had a long time that looks pristine so I'm trying to get it running again.
     
  13. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    Does anybody know if it would hurt to fit this to my new motor? I've included pic of old motor and new
     
  14. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,982
    744
    Looks the same size, as long as it spins at the same speed should be ok, try it and see.


    Ahhh nice pics of steam train through Preston...chuff chuff
     
  15. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
     
  16. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    Ha, Yeh wigan reporter comes in handy for something!
     
  17. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,982
    744
    If you're from Wigan, your name should be Pie- Eater lol....
     
    Dr.killjoy likes this.
  18. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    Too true!
     
    Dodgydave likes this.
  19. Paulnoviceb

    Thread Starter New Member

    Jan 23, 2016
    11
    1
    What do U think about that diode though? Should I transfer it to the new motor?
     
  20. Dr.killjoy

    Well-Known Member

    Apr 28, 2013
    1,190
    156
    No....
    Mount the motor and give it a try ..
     
    Dodgydave likes this.
Loading...