DIY Automatic HLT water fill sensor

My DIY water sensor control panel.
For the last couple of weeks I have been working on a controller to automatically fill the HLT to a desired volume, then turn off and sound an alarm. At first it was going to be a old garden timer with an on off sensor for the power to the garden timer. After a little brainstorming and trial and error I came up with a control box that with a push of a button turns on the water, then it can be set to turn off automatically at 3,4,5 or 6 gallons. It also has four LEDs that show what the current level is. As it gets to 3gals the LED comes on, at 4gals and so on. This is just the beginning of a semi automatic brewery going from outside to my basement. The circuit that controls the thing is really simple so if anyone wants more info on building one let me know.
Here's a few pics that might explain it a little better. .













I would also like to see other water sensors if anyone uses one.
Oh yeah and the sensor that actually goes in the kettle is still a work in progress. Might be made out of PVC but not sure about PVC being in 170F water. It needs to be a removable "stick" that holds metal pieces that triggers and completes the circuit.

This looks great. Can you set it to measure less than 3 gallons? What about having a switch for a quart or .5 gallons, a switch for 1 gallon, 2, 3, 4. Then you could make any combination

I would like to know more about the hose device you've gutted there! Does it have a flow sensor and a solenoid in it, or just the solenoid? How do you know how much volume there is?

I'm pretty sure you would NOT want to use pvc for this. You could use copper if you keep the sensors insulated from the pipe. Is this going to be something where the water makes contact with the sensors and completes the circuit? Maybe you could use a float that triggers different sensors at different heights. Neat project.

ArtVandelay said:

This looks great. Can you set it to measure less than 3 gallons? What about having a switch for a quart or .5 gallons, a switch for 1 gallon, 2, 3, 4. Then you could make any combination

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I set it up for 3-6 gallons because that's mainly what I use. It's pretty specific to my setup. I usually use 4-5g for mash and 5-6 for sparging. It's main intention was so I can set it to 5g and walk away since right now I watch it pretty close, and running through a filter it takes a bit of time that I could be setting something else up. I figured if I need lets say 5.5 gallons I would set it for 5 wait for the alarm to go off then just top it up from there manually.

CapnBry said:

I would like to know more about the hose device you've gutted there! Does it have a flow sensor and a solenoid in it, or just the solenoid? How do you know how much volume there is?

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I can't remember what the model is right off hand for the garden timer but when I get home I will update it here. The way it works is with a basic motor and gears that opens and closes a valve with a switch that gets turned on/off as the gears move. So when I push a button it supplies power to the motor and it opens the valve, then there's a simple water sensing circuit that when the water reaches the point in the kettle where the sensor is placed it completes the circuit and supplies power to the motor and shuts of.

horseinmay said:

I'm pretty sure you would NOT want to use pvc for this. You could use copper if you keep the sensors insulated from the pipe. Is this going to be something where the water makes contact with the sensors and completes the circuit? Maybe you could use a float that triggers different sensors at different heights. Neat project.

Click to expand...

Yeah that's what I thought about the PVC. I think online it said max temp was 140F. The copper might work. But yes the water completes the circuit so I would have to insulate around them somehow. I've also been looking at float switches but it should work fine without them as long as I can find something to mount them to that I can also run the wires up through the middle.

Update: The brand of the garden timer that I hacked up was Nelson. There wasn't any kind of model number or anything. I think it's fairly old. I received it from a friend that had it laying around. You can buy just the valve part on Amazon from different company's such as Rain Bird for 14$ but it probably works a little different than what I have.

PVC would be bad. You could go with CPVC if you don't think you'll ever bring your HLT to a boil. (See this thread.) Still, I'd go for copper or stainless.

Thanks for the link to that thread about PVC. It wouldn't get up to boiling temps only mashing but the hole idea with plastic leaching stuff out is a big deal to me.

I finally came up with the sensor part of this project. After thinking a lot of what I can and should not put in the HLT I decided on a piece of wood with copper wire running down the side which completes the circuit to trigger the controller. I'm hoping the wood won't impart any flavor so test runs are going to be needed. I went with wood for a couple of reasons, it was easy to work with and I couldn't come up with anything else that was both nonconductive and food safe.

Check this out, makes the design a bit simpler:
http://www.electronic-circuits-diagrams.com/alarmsimages/6.gif

Vesku said:

Check this out, makes the design a bit simpler:
http://www.electronic-circuits-diagrams.com/alarmsimages/6.gif

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Nice link. This looks very close to what I did but then also attached the water valve. I wish I had that diagram when building this.