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I have a latching solenoid valve laying around, the original controller is broken and I'd like to make it work using a uC. I don't have the electrical specs of the valve. The broken device was using a 9V battery so I guess the latching valve works at around 9V. When I try it on my workbench without water and apply a short 5V pulse it clicks in and out so it looks like working. But I'm not sure it will work when there is water pressure. Anyone has experience on these type of valves? Is there any dependency between the applied voltage and the water pressure? Or can I make the simple assumption that if it works without water it will also work with water pressure? Thanks in advance for any help, Pedro

EDIT: Add some photos

Valve: latching solenoid valve photos

Controller: enter image description here

The controller has two 9V PP3 connectors for two 9V PP3 batteries. It looks like they are using a transistor to select the battery, so they might be with reversed polarity, in order to make the positive or negative pulse to the valve.

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  • \$\begingroup\$ I expect someone has but this is not a valid EE question. \$\endgroup\$
    – Andy aka
    Commented Apr 27, 2016 at 17:11
  • \$\begingroup\$ Why is it not a valid EE question? \$\endgroup\$
    – Pedro NF
    Commented Apr 27, 2016 at 17:17
  • \$\begingroup\$ Read the site blurb on valid questions and you'll see that questions seeking recommendations for specific products are off-topic and will get closed. \$\endgroup\$
    – Andy aka
    Commented Apr 27, 2016 at 17:23
  • \$\begingroup\$ Ok, to comply with the site rule I changed my question. Thanks for the remark. \$\endgroup\$
    – Pedro NF
    Commented Apr 27, 2016 at 17:38
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    \$\begingroup\$ "they might be with reversed polarity, in order to make the positive or negative pulse to the valve". That sounds right - the 4 valves share a common connection (ground?), and each is driven by an IRF7307 dual MOSFET, which suggests that positive and negative supplies are required (trace the circuit from batteries to valves to confirm). If you only have +5V then you could use a 5-9V boost converter and full bridge drivers. \$\endgroup\$
    – Bruce Abbott
    Commented Apr 29, 2016 at 18:20

2 Answers 2

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Just because it seems to work with 5V on the bench doesn't mean that it will work reliably (or at all) in the operating environment. You should look up the specs of your solenoid to get its operating voltage range (eg. 6.5 - 12V). If it doesn't have a minimum voltage specification then you must assume that it requires 9V.

If you don't follow the specifications then it's your fault if it misbehaves. And any damage caused by it not operating properly will be your fault too. Why take the risk? Perhaps you only have 5V and are hoping it will be enough. Don't do that. Do the job properly and provide the solenoid with the voltage it is designed to work with.

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  • \$\begingroup\$ Well, the problem is that I don't have the specs and I can't find them anywhere, I only know that the original (broken) device was using a 9V battery. And according to the forum rules I can't write here the valve's reference number... \$\endgroup\$
    – Pedro NF
    Commented Apr 28, 2016 at 9:49
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    \$\begingroup\$ You could trace out the broken device's circuit to determine what voltage it was sending to the solenoid (my bet is 9V, since that would be the most efficient use of the battery). Then you know what voltage the designers knew it needed, and it might even help you to design your own driver circuit. electronics.stackexchange.com/questions/171169/… \$\endgroup\$
    – Bruce Abbott
    Commented Apr 28, 2016 at 18:46
  • \$\begingroup\$ I added a photo of the controller and a new comment about it. \$\endgroup\$
    – Pedro NF
    Commented Apr 29, 2016 at 13:04
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Every solenoid valve has specs, those specs can only be met given that you provide the voltage required. Expected life expectancy of solenoid is also effected if you provide voltage below min ratings.

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  • \$\begingroup\$ Why would life be effected when under driven? \$\endgroup\$
    – Passerby
    Commented Apr 27, 2016 at 19:43

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