Please could I know if the diodes in EESE question “Control speed of Nidec fan” ARE zener diodes (as the symbols sugest) or normal diodes as on another article they had the exactly the same circuit but in the component list the diodes were given as 1N4148 (norma diodes) Thanks.

  • \$\begingroup\$ ......... What? \$\endgroup\$ Jul 5, 2013 at 19:26
  • \$\begingroup\$ Crystal ball error 404: Unable to access "Control speed of Nidec fan". (in other words: please supply us with enough information to enable us to give a meaningful answer.) \$\endgroup\$ Jul 5, 2013 at 19:34
  • \$\begingroup\$ Edited in the link to the base question located by pjc50. \$\endgroup\$ Jul 5, 2013 at 19:49

1 Answer 1


I'm guessing you mean Control speed of Nidec fan? and the schematic in its accepted answer: enter image description here

I read those symbols as Schottky diodes (low forward voltage); while I've not analysed it in detail, I believe that replacing them with normal diodes will only slightly limit the max and min duty cycle.

  • \$\begingroup\$ Thanks for you reply. I suppose the best way to verify is, at this point, is to build the circuit and test it. \$\endgroup\$
    – Joe
    Jul 5, 2013 at 20:05
  • 2
    \$\begingroup\$ They are definitely schottky diodes. \$\endgroup\$ Jul 5, 2013 at 21:12
  • \$\begingroup\$ I agree with Connor. Schottkys make sense in this circuit, although a fast-recovery diode can work too. Zeners have single-break bars rather than the curlies from the Schottkys. \$\endgroup\$
    – Jon Watte
    Jul 6, 2013 at 5:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.