Diode needed to power Liquid Solenoid Valve?

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bibbli
 
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Diode needed to power Liquid Solenoid Valve?

Post by bibbli »

I have a cheap remote control switch (that I purchased) powering and switching my AC adapter which is rated at 7.5v 1A.

This scheme seems to work ok now for opening and closing the valve remotely, but wondering if a diode is needed long term to protect the integrity of either the adapter or the switch, or to ensure it functions reliably?

Also, assuming polarity across the valve doesn't matter?

Thanks!

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adafruit_support_bill
 
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Re: Diode needed to power Liquid Solenoid Valve?

Post by adafruit_support_bill »

How do you have everything hooked up? Switch controlling power to the adapter which is in turn activating the solenoid?

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bibbli
 
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Re: Diode needed to power Liquid Solenoid Valve?

Post by bibbli »

Yes, exactly.

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Re: Diode needed to power Liquid Solenoid Valve?

Post by adafruit_support_bill »

In that configuration, a diode would protect your AC adapter from the negative voltage spike that occurs when the solenoid coil is de-energized.

You would want a diode rated for at least as much current as the solenoid. And you would wire in parallel to the solenoid coil - but in reverse polarity. That will short-circuit the negative voltage spike back through the coil.

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bibbli
 
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Re: Diode needed to power Liquid Solenoid Valve?

Post by bibbli »

All that makes sense. Thanks so much for the clear and speedy response!

Side note, we've made great use of the valve to maintain a siphon to collect grey water in tanks from an upstairs tub.

Thanks again.

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