DIY Auto-Top off with Solenoid

[tang_man_montreal]

Gudwyn,

Where are the pics?

[Gudwyn]

Sorry, no pics yet.

BTW, this setup is running my RO/DI not my tank. Mainly because the tank doesn't exist yet. :-P

[Old Yeller Tang]

I say that because I no longer have to lug 5g jugs of water to my reservoir every 2-3days!

I have my auto-topoff on a timer so it only comes on once a day and that rids any constant clicking sounds as well as keeps it off after 5min just in case something goes wrong with the float switch. I added a DI after the solenoid just in case it leaches any metals out.

Hard to take a clear pic due to all the plumbing any limited space I have under the tank.

[Zephrant]

Very cool! Thanks for the extra pictures too.

Zeph

[dsb1829]

Very good diy solenoid topoff thread. Good reading. Thanks to all for the effort. I am sure this will come in handy at some point down the line.

Just a thought, why aren't any hobbiests using non-intrusive sensors to control the solenoids. A simple float/optical interference sensor would be a great way of tracking water level without the troubles of mechanical float switches. Just seems to me like a more reliable system could be put together. Food for thought

[Zephrant]

That is certainly possible, and would be a great solution, but it is a little more complicated to build/install. The setup I like is the air-hose to a pressure-sensor. It is about as fail-proof as you can get, but again, more complicated/expensive.

Zeph

[Gudwyn]

Ok, as promised some pics. This is my first pic attachment at RC, so if you see red x's, just humor me and say you really like the setup.

Topoff runs my RODI, but same circuit can be used on aquarium. I connected one coil lead to the com lead on the relay (using big blob of solder). Then connected NC to the high level switch that then connects to positive on the 12v dc. The low level switch bridged the NC (hot) to com/coil leads on relay (active). The solenoid, led, and relay coil are all wired from active (com/coil) to the negative on 12v dc.

Drill some holes the size of 1/2" PVC, glue a bunch of fittings together, and there you go.



BTW. In case you are confused, yes I reversed the com and NC from the schematic and their normal function. But hey, that way I could use a big blob of solder.

[tang_man_montreal]

Very nice!

I especially like your PVC work there with the float switches.

A+ work man!

[Gudwyn]

Thanks

[tang_man_montreal]

Gudwyn,

I'm Curious.. Did you use the solenoid from Zephrant's original plans?

[Gudwyn]

Yes, it's the 12v version of the mini solenoid from mcmaster. Don't know if anyone found one without metal yet. Doesn't matter on the input to the RO/DI, but it would be nice to have an all plastic on the aquarium topoff when I build it.

[Foster]

Im very late on this thread - Im going to have to build one of these.

[Zephrant]

Nicely done. I like the PVC setup too- Looks good, and is very clean.

Zeph

[RalphP]

Hi
Instead of wiring the float switch to a solenoid can you wire it into a powerhead?I dont have a ro unitI wanted to hook it up to the ph in a 5 gallon bucket ,that way I can stop dripping it.
Thanks

[Valab]

Nice thread and I commend Zeph for the presentation. I don't have anything in particular to add, but do want to point folks to this site for more ideas on how to built and 'accident-proof' a water refill system:

http://avdil.gtri.gatech.edu/RCM/RCM...illSystem.html

[Zephrant]

That's a great write-up, and definitely more failure-proof than the above. However I would like to see the statistical analysis that determines how "much" safer it is. I guess we would have to know the MTBF of the floats and the solenoids in the reef environment to calculate that though.

Can you tell us which solenoids you are using?

Zeph

[Valab]

Zeph,

It's not my site. The designer is a prof. at Georgia Tech. I've asked him about a few things over the past couple of years
and have found him very amenable to answering questions. I don't know the background behind the 'quad-logic' stuff , but I trust that he does and hope to emulate his system. The acrylic float switches he uses are pretty darn cool but beyond my fabrication abilities.

The rest of his site is well worth reading for ideas.......

A few months back I happen to be listening to NPR news and got a chuckle when they interviewed him regarding some NASA-related news story.

[RicoJ]

Zeph, so have we determined that the solenoid is a good one for our purposes or have you found something better? Also can I put this solenoid on a timer so that it only runs during certain times?

[Zephrant]

I've not found a better one, but I have not looked either.

Running it on a timer should be great. I don't because mine runs though a kalk reactor, and I would rather dose kalk all day instead of in a batch (when the timer kicks on.)

Zeph

[jfinch]

(hope you don't mind if I barge in on this thread and post a few pics)

I built a float switch close to a year ago which drives a small pump located in a bucket of DI water. I had problems with the reed switch "sticking" after about 6 months of use. I'm using a Madison switch and after talking to them decided it was due to high inductive start-up currents. A general solution to this problem can be found on their website here: http://www.madisonco.com/reference/floatswtech.htm. My solution was similar only I also reduced the current through the switch by using a triac. Here's a schematic of my fix:




Here's a picture of the assembled circuit:



And here's the end product. All the electronics fit nicely into a small piece of 3/4" pvc pipe:



No problems now and I can run any motor up to 4 amps!

[manderx]

i'm going to get this solenoid for my next project. it costs twice as much, but they don't appear to have brass like the 'red ones' do. and they look pretty darn cool too.

http://www.usplastic.com/catalog/pro...Solenoid+Valve

[Gudwyn]

You can also reduce current thru your float switch by using a relay. Same concept. See various posts in this thread for schematics.

[Zephrant]

Very cool- Thanks for posting that!

Zeph

[jfinch]

You can also reduce current thru your float switch by using a relay.

Yes, that was what I orginally planned to do, only I wanted to keep it all as small as possible. And I couldn't find a relay small enough to fit the bill. As you can see in the picture, the triac is very small (and is in essence a relay/switch). Maybe I just didn't look hard enough... are there small (AC) relays?

[Cuervo420]

bump