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 .


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

 

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

 

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

Cheers MrChips , appreciate the information

 

Also advisable to place the diode directly across the coil itself, rather than in any remote connector etc.

 

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,

 

Also advisable to place the diode directly across the coil itself, rather than in any remote connector etc.

Cheers Max , yeah , the connector is directly plugged onto the coils , should be OK

 

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