how to read 110vac with plc's dc inputs?

GW_controllers · Aug 5, 2005

I am looking for a solution for how to read the presence of a 110 vac signal when the plc I am using only has dc source or sink inputs. I know the obvious answer of using a relay but would like to know of any solid-state interface devices that anyone would recommend.

g.robert · Aug 5, 2005

you could use a cheap bridge rectifier at each 120 vac to convert to pulsing DC. If your DC inputs at PLC are rated 12-130 vdc your OK. If rated 0-30vdc you will have to also drop the voltage.

Mickey · Aug 5, 2005

Good stuff ( do you have analog input )

http://www.miinet.com/products/sg_ac.shtml

Terry Woods · Aug 5, 2005

Opto-Isolator.

Try OPTO22... look for G4IAC24A

TConnolly · Aug 5, 2005

I use din rail mount opto-isolators for 1 to 3 points. If more points are needed, I buy another IO card.

monkeyhead · Aug 6, 2005

Alaric said:
I use din rail mount opto-isolators for 1 to 3 points. If more points are needed, I buy another IO card.

completly OT, but i'm diggin your new user icon.

TConnolly · Aug 6, 2005

monkeyhead said:
completly OT, but i'm diggin your new user icon.

Its a typical days work.

CaseyK · Aug 6, 2005

I've used the OPTO's and have been very satisfied with them.

Coyld be he has a micro with dc in only, no expansion capabilities.

Or maybe no budget.

Or.....nevermind.

how to read 110vac with plc's dc inputs?

GW_controllers

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Terry Woods

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TConnolly

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TConnolly

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