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September 10, 2018 15:38

DIN rail mount elays for 12VDC 5W solenoid valve

Could someone please advise the most approriate DIN rail mount general purpose non-latching relay for switching a 12V DC 5W solenoid valve from teh IOT2020?

 

Thanks

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September 25, 2018 07:44

Hi Peter. Thanks, yes, I purchased this at the same time as the IOT2020. I was looking for advice on selecting relays. I want to use the IOT2020 via the IOShield to switch a 12V power supply to the solenoid valves. How do I specify the relays? Is the coil voltage the voltage from the IOT2020 pins and the switching voltage that required by the valves?

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October 2, 2018 04:31

@Mldavies The COIL voltage of the relay would be the rating compatable with the IOT2020 outputs, so typically up to ~30V (24V normally for industrial) but the IOT2020 IO module can also handle 12V so you would just need a single voltage power supply (12V). For what would drive the solenoid, this would be the contact rating of the relay and are nearly always rated with AC switching (240V @ 10A for example) and DC switching (30V 10A for example.) THe big difference is due to the ability of the relay to be able to break the arc that may form when the contact opens, AC will do this on its own typically as it will pass through 0V, DC can be funny hens the much lower voltage rating for DC.. For your application (12V 5W = only 420mA) any relay rated for mains voltages will be ok, the trick is getting one that takes lower current for the coil, this is part of the specification (say 12V, 200mA) Also for your application, a simple MOSFET switch would work very well, look on line for 3D Printer mosfet drivers. I have a video here all about it https://www.youtube.com/watch?v=6WwCqxSaF_w&t=1272s I know this is for a 3D printer but it will work equally well with a solenoid, you may just have to add a DIODE across the solenoid.

October 2, 2018 04:30

@peteroakes That's really helpful thank you so much. PS Thanks also for all the great videos on the IOT2020. They too have helped me hugely.

September 18, 2018 08:20

Have you considered this as an option https://uk.rs-online.com/web/p/plc-i-o-modules/1354133/

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