Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
Konstantinos L. Angelis
03/07/17 12:05
Read: 635 times

#190758 - Relay noise, add a zener with the flywheel diode
Responding to: Mahmood Elnasser's previous message
A significant part of relay noise is coming from contacts due
to the coil not charged/discharged fast enough because of the
surrounding magnetic field.

The typical flyweel diode is not an industry good practice because
it keeps running the coil from the magnetic field until it is "drained"
and the relay contacts are in a unsafe holding force during that period.

By adding a zener then the coil cut-off is far more fast because it
is running for a smaller part of the time until total cut-off.
So the contacts act more quickly and the noise is far less than
without the addded zener.

For a 12V coil relay a zener or 12V to 18V is a valid option, always
in series with the flywheel diode connected cathode to cathode
(or anode to anode).

List of 13 messages in thread
Relay noise      Mahmood Elnasser      02/09/17 21:27      
   metal box      Stefan KAnev      02/11/17 02:32      
      not possible      Mahmood Elnasser      02/12/17 12:30      
   Are the output leads,inside the relay,...      Kerim Fahme      02/13/17 10:28      
      FG Relays      Mahmood Elnasser      02/16/17 16:31      
   can you ....      Erik Malund      02/14/17 07:03      
      not piggies      Erik Malund      02/14/17 10:55      
         LCD Shield      Mahmood Elnasser      02/16/17 16:42      
            no scientific base      Erik Malund      02/17/17 07:09      
   Avoid Relay noise addin a zener !      KONSTANTINOS L. ANGELIS      03/06/17 14:25      
      Source of noise      Mahmood Elnasser      03/07/17 09:38      
         Relay noise, add a zener with the flywheel diode      KONSTANTINOS L. ANGELIS      03/07/17 12:05      
            Experimentation      Mahmood Elnasser      03/08/17 00:30      

Back to Subject List