Query regarding DIODE across a coil or don't I ?

Thread Starter

Bob Stevens

Joined Aug 27, 2021
4
Hi Folks , I have a query regarding diodes across a coil from a PLC output , I need to replace a number of plugs onto some relays and the client has supplied the connector plugs which are empty shells . I am trying to figure out the size of the diode for installation as per the schematic . Voltage is 24VDC onto a very small valve/manifold arrangement . Can anyone advise which size diode might be suitable or if it can be removed from the circuit .
I'm a bit of a newb to this type of thing but looking to learn a bit more about it .
1630117240416.png

Hoping the brains trust will enlighten me . Circuit is part of a Multivac food packaging machine .
 
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MrChips

Joined Oct 2, 2009
24,442
Check with the manufacturer of the PLC. It may already contain flyback suppression diodes.
If not, any 1N4001-1N4007 series diode will do.
 

Deleted member 115935

Joined Dec 31, 1969
0
Check with the manufacturer of the PLC. It may already contain flyback suppression diodes.
If not, any 1N4001-1N4007 series diode will do.
and even if the plc does have them,
adding your own in parallel wont harm,
 

Thread Starter

Bob Stevens

Joined Aug 27, 2021
4
and even if the plc does have them,
adding your own in parallel wont harm,
Thanks for the input Andrew , yes , I am going to go with the 1N4004 because everytime these guys find me another drawing for this machine there are more diodes showing up in every part of the schematic.......... oh well , good practice and good experience I suppose
 
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