How to control Orbit 62035 valve

As an update to my previous post, I took a look at the Orbit 62035 valve, which works with the older Orbit’s yard watering system 62032. This valve is white colored, and has a standard 3-pin 3.5mm stereo audio plug.

To figure out how to control the valve, my initial guess is that the valve contains two coils, one opens the solenoid and one closes it. To verify this, I measured the resistance between the 3 pins of the plug. It turns out that pin 1 and 2 have a 4.5 ohm resistance, while pin 1 and 3 have a 0.9 ohm resistance. The 4.5 ohm resistance is reasonable, as it’s roughly the same with the Orbit 91592 valve that I used previously. But the 0.9 ohm resistance is strange — it clearly indicates a coil but the resistance seems too lower.

Having no other reference, I went ahead to apply voltage on the pins to see what would happen. Interestingly, applying +24v on pin 1 and 2 successfully opens the valve, but doing the same on pin 1 and 3 fails to close the valve. I tried everything I could to figure out what went wrong, but nothing came up. Out of luck, I decided to buy the full kit (62032) and reverse engineer the control unit a little bit. When I opened the control unit, I found that the entire circuit board is covered by a thick layer of water-resistant paste. This didn’t look good. However, I did notice several big resistors, each reading about 3.9 ohm. The size of the resistors seems to suggest that they are rated at 2W.

Given this finding, my suspicion is that applying +24v directly across pin 1 and 3 discharges the voltage too quickly, thus cannot close the solenoid properly. In fact, given the 0.9 ohm resistance, a momentary current of 26 Amp is produced, which sounded quite scary. Adding a 3.9 ohm resistor is probably used to limit the current, slowing down the voltage discharge. This actually helps to build the electromagnetic field in the solenoid, allowing it to close properly. The idea turns out to work like a breeze: I connected a 3.9 ohm resistor between pin 3 and ground, and this time the valve nicely closed. At this point, I’m pretty sure I’ve figured out how it works. 

You might wonder what the differences are between this valve with the Orbit 91592 valve. Here are my two cents:

Pros:
– 3.5mm stereo audio jack makes it easy to connect (in comparison, the 91592 valve requires custom connector)
– Pin 1 can remain connected to +24v, while grounding pin 2 or 3 is used to control the opening/closing of the valve. This simplifies the circuit design a lot. In fact, only two low-side drivers are needed to ground pin 2 or 3, which is much simper than h-bridge driver required by the 91592 valve.

Cons:
– Seems to be of its own kind on the market (my impression is that this is a discontinued product). Most other latching solenoids available on the market are similar to the 91592 valve. Fortunately Walmart still carries this product currently, but I don’t know how long it will last. 

Below is a sketched schematic when using this valve to replace the 91592 valve. As you can see, the circuit is much simpler than before. The driver can use either a darlington transistor (such as MPSA14), or an N-type MOSFET (such as IRF510).

20 thoughts on “How to control Orbit 62035 valve

  • August 3, 2010 at 5:59 am
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    Thank you Ray! I kept on wanting to use this, but just never seemed to get around to take the time to work out the details.
    I have 4 of these I can use, since the controlling unit went belly up several years ago. Thanks for sending me an e-mail with a heads up. I owe ya one 🙂

  • August 9, 2010 at 8:14 pm
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    Hi Ray
    First of all, my compliments for your blog.
    Do you have any information/technical specs about these valves ?
    Something like how many PSI they can stands, if they need a minimum pressure to work, and so on ?
    Thanks
    STeve

  • August 11, 2010 at 10:24 pm
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    I don't have the exact specifications for these valves, but I do have an Orbit 56158 1-dial timer valve which says the maximum operating pressure is 100 PSI. I think they use the same type of solenoid, so I guess they are all 100 PSI max.

  • August 12, 2010 at 6:55 am
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    Steve: 10 PSI min., 80 PSI max., from the valve packaging.

    Ray: why are you using 24v? The battery is 4.5v. Is there a switcher in the 62032 boosting voltage to 24v only to turn valves on/off? I'm trying to fix mine that just failed, maybe this is why….

  • August 12, 2010 at 9:10 pm
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    Yes, I am pretty sure there is a 24v voltage booster inside the controller unit. These valves cannot work with 4.5v, it's too low to operate the valves.

  • August 12, 2010 at 9:26 pm
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    By the way, if you've tried the control unit, you should notice that when you set the valve to open or close, it usually takes 1-3 seconds to actuate the solenoid. This is because the voltage booster is building up charges. For an example voltage booster circuit, look at my first blog post (the minty valve project).

    It is actually possible to use the Arduino directly for boosting voltage, thus saving a booster IC (LT1303 in this case).

  • August 19, 2010 at 5:15 am
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    Hi Ray,

    Nice job. I'am plannign to by a valve like this one and with an arduino to operate it for my mist patio sistem. To stay open for 7 sec and close for 10 sec. This valve is strong enough for this? How I can use arduino to make 24V so I no use LT1303 ? Thanks

  • December 1, 2010 at 1:10 pm
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    Ray, I've found this post through google search by chance. Thanks you very much. I've been wanting to connect this valve to my HA irrigation controller for a while but never got around to it. I guess I'd have to connect open to one zone and close to another zone and activate "close" zone for a few sec. Should be easily achievable.

  • December 5, 2010 at 7:18 am
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    I have a spare Insteon 2450 low voltage relay module i am considering connecting up to one of these valves to control a single zone drip/mist system. I presume I could connect a +24VDC supply and wire up both the NO and NC to the valve with the resistor. My question is how reliable are the valves and should i install a backflow preventer since my outdoor water faucet also supplies my drinking water. Or wold I be better off with a higher quality valve?

  • January 20, 2011 at 10:37 pm
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    To Elvis, yes, you should put a kickback protecting diode. It was not included in my diagram, but there should be one. Something like 1N4001 or 1N4007 should work.

  • February 1, 2011 at 6:23 pm
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    Ray, this is fantastic. Thank you very much for this!! I want to use one of these valves to direct water to a RODI unit. I will have a float switch in a water jug, when the water level gets low, the float switch will active open the valve and when the jug is full, the float switch on top will activate the close.

    Few questions for you. Is there a power supply you would recommend to apply the 24v to pin 1? Also, when open and closed, should the 24v be applied continuously or should it only be applied for the 3 seconds or so it takes to open and/or close the valve?

    Forgive me if my questions seem amateur. It's been 10 years since electronic engineering courses and this will be the first electronics project for me since then.

  • February 2, 2011 at 8:53 am
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    @Dan: I am currently using a boosted +24V from my first blog post (http://rayshobby.blogspot.com/2010/06/minty-water-valve-controller.html), but you can certainly use a 24V power adapter. Since these are latching solenoids, they only need to be energized for an instant of time — I would say something like 50ms-100ms. Don't apply continuous 24V for more than that long, because it may damage your power adapter (the solenoid resistance is very low).

    Also, a couple of components are missing from the diagram. Please see my updated blog post here: http://rayshobby.blogspot.com/2011/01/update-on-how-to-control-orbit-62035.html

  • June 10, 2011 at 1:42 pm
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    Are these latch solenoids inside the valve, so you just have to pulse it to open and close it?

    • July 13, 2016 at 10:07 pm
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      @Anonymous – A little late to the game but Orbit’s documentation says 250mA per latching valve. For those of whom are wondering, 24v is a legacy carry over from most automated systems, now it’s our cross to bear 🙁 It was the voltage standard for basically everything industrial (take a look at all those Siemens PLC gear, all 24v.).

      How did your valve hold up? I have three zones I want to DIY, fully underground off 3/4ths sch 40 PVC, using the Orbit 58874N (13.20$ hope this is latching too…) + the Rainbird 32SA (28 for a set of 4, along with a drip irrigation system for potted plants. I was thinking about using the standard ESP8266, throw ESPopenRTOS on there along with some moisture sensors (if I can find some that are better than those crappy DHT22’s that last a week), so I know exactly how much each region is getting (I’ll couple the uC with some outdoor-rated crap and throw an 18650 li-ion in there, then seal it up with epoxy to waterproof it)).

      • July 25, 2016 at 11:56 pm
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        Indeed 24VAC being an industrial standard means we have to live with it for many years to come, even though I think the latching valve is much better and more efficient.

        I didn’t use the latching valve for a long time so I don’t know how they perform in the long run. The boost converter technique seems to work pretty well and can reliably open/close the valve. I am in the process of finishing up the new OpenSprinkler Bee design, which also uses a ESP8266 with three channels of H-bridge to control 3 independent latching valves.

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