24VDC valve

[Kalu1]

Hey there,

I have simple question. I think it was already answered in the forum, but I am bit confused with the answers for olded devices etc.

For example here:
https://opensprinkler.com/announcing-the-first-dc-powered-opensprinkler-v2-3-dc/

There is said:

What’s the operating voltage range for v2.3 DC?
Although v2.3 DC comes with a 9V DC power adapter, you can power it with any voltage ranging from 5~24V DC.

But I have 3.0 with 7.5VDC adapter.

Can I connect 24VDC valve to OpenSprinkler 3.0 DC version?
Do I need use 24VDC power supply?
If I try to use original adapter 7.5VDC and it will not be enough, can it cause damage in electronic?

Thanks
Lukas

[pippin88]

Use the supplied adapter!

DO NOT connect 24V to your DC Opensprinkler.

You can use 24VAC solenoid valves with your DC OpenSprinkler. I don’t think I’ve seen 24VDC solenoid valves around.

[Kalu1]

24VDC is industry standard. Every factory has 24VDC valves.
It would be good to edit link above where is said that 24VDC is ok.

Can I use a relay betwen opensprinkler and valve? I have 5VDC relay for arduino could be work?

Thanks

[Kalu1]

Could I ask again? What will hapen if I connect 24VDC valve? (with the original power supply)
Thanks

[Kalu1]

Ok, in the attachment is print screen from this web where is said 24VDC is ok (for valve and even for power supply). The answer above really confused me. Can someone answer me please? It is enough answer like “24VDC valve is ok”.

Thank you

Attachments:

1. 

   2019-04-11_9-43-29.png
   

2. 

   2019-04-11_9-46-05.png
   

[TorC]

I would trust what Ray says, and expect any non-latching valve designed for up to 24V to work on any acceptable power supply, so you can use your 24VDC valves.

It looks like 7.5V input is the minimum supported by all specifications, but 5V appears to work. There is an internal boost converter to provide the voltage needed to operate the valve, and then a lower voltage is sufficient to keep it going.

[Kalu1]

Thanks for the answer. Today I tried my valve with laboratory powered supply. The result is for the opening is enough 7,5 V and even 1.5 V can hold the valve.
The valve was GSR force actuated valve. 11W 24VDC

I also tried Festo pneumatic valve (just cause a different coil).
3.3W 24VDC
The valve opened with 13.5 V and a closed below 4 V.

So I guess it will work and 7.5VDC power supply is ok:-).

Lukas

[Ray]

I honestly have never seen 24VDC valve myself — most sprinkler valves are 24VAC. Thought this sounds ironic: if you use DC to operate AC valves, you can actually use lower voltage (typically 12VDC is sufficient to operate 24VAC valves). This is due to the way AC valves work, and the specifics are explained in this article by me:
https://rayshobby.net/wordpress/understanding-24vac-sprinkler-valves/

Now, regarding 24VDC valves: I wouldn’t recommend powering OSDC with 24VDC because the voltage regulator on the driver board is not really rated for 24VDC — I think it still works for a short period of time but it’s beyond its maximum rated input voltage, so I think it’s a long-term reliability issue. I would suggest that you try to use 12VDC to power OSDC, and then see if it can operate your 24VDC valves. I think there is a good chance it will, because most valves requires a high impulse current to energize and then you can lower the voltage to provide holding current. OSDC is exactly designed to do so: it generates a high impulse voltage and then lower the holding voltage to the input (in this case 12VDC). That said, I’ve never seen a 24VDC valve myself so I cannot say for sure this works. You can give it a try.

Sorry, right after I wrote the above message, I saw you have already tried your valve with 7.5VDC. If it works, then I am pretty confident it should work with OSDC with the 7.5VDC power supply that comes with it.

[Author]

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