PLC PSU

[Skiroy]

I want to build a Allen Bradley PLC training station at my home. All of my sensor and devices are 24VDC so I know PLCs are either in 120VAC or 24VDC versions,right. So I would need a 24VDC version PLC. If I want to connect 120VAC devices such as a motor I would just use a relay/contactor with a 24VDC coil.

My question is in regards to the PSU I will need for my for my 24VDC PLC. Im assuming it would have to be rated amperage wise to handle powering the PLC and and the input and output Busses for my devices.

So:

1. Can I just use any old wall wart rated at 24VDC output covering my amperage needed?

AND

2. How would I calculate what amperage I need for my devices such as Photosensors,ice cube relays,contactors,limit switches ect.?

[Al_The_Man]

Allen Bradley PLC's can be 120vac or 24vdc this just powers the PLC, the power for I/O is usually a separate supply, although if it is a 24v PLC I guess you could use the same P.S. for both.
I would use a good quality linear or switching supply, if you rate it at about 10amps it should cover all.
Al.

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