PiFace Output Relays

ge0rgej over 12 years ago

Can anyone tell me if the PiFace relay contacts should only be treated as volt free contacts - or can

a load be switched across them ..... if so can anyone tell me the maximum load

thanks

George

mcb1 over 12 years ago

George

A volt free contact means there is no voltage on them from the host or control circuitry.

Have a look here for the answer to your other query
http://www.element14.com/community/roadTestReviews/1468

mark
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ge0rgej over 12 years ago in reply to mcb1

Mark

thanks for your reply - I appreciate the volt free concept

My question is if I switch an external voltage across the Common / Normally Closed output relay what is the maximum
load (A) the contacts will take

George
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mcb1 over 12 years ago in reply to ge0rgej

I presume you read this bit.

The relays must not be used to switch voltages greater than 20V or currents greater than 5A

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ge0rgej over 12 years ago in reply to mcb1

I did - thanks
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mcb1 over 12 years ago in reply to ge0rgej

George
Cheers

I've made a comment (and chased an inapproriate blog showing mains being used) that this really needs to be in the documentation and starting guide.
Having it on the outside of the box, is really not the best practice.

For anyone reading this
While a component may be rated for a maximum, it is the environment around that often dictates a lower limit be applied.

For the PiFace, the pcb is NOT designed for mains voltages, and the track widths don't suit any higher currents.

Mark
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