Vertical level switches

[Kobus Jooste]

Hi there all

 

I am currently working on a design of a very small self watering garden, and want to find an effecient way to switch a small pump on and off.  Even the 15 minutes of mechanical timers is too long, and the cost of a fancy programmable jobby is not going to make the unit sensible in terms of sales potential.  I need to fill a small overhead water canister that will then drain to the planters a few times a day.  I have been looking at these little vertical level switches as an option

 

 

 

I can get them in South Africa too, but have never used one before.  Are they reliable?  What are the do's and don'ts (eg particles in water) that I need to know about as the specs on the online shops are sketchy.

[Carey Ma]

I have no idea about verticle level switches but I like using X-10 home automation. Simple, relatively non expensive and fully programmable.

[Rik Kretzinger]

I have found them to be reliable.  They take up little space and work great.  I like the 90 degree ones better.  As they are easier for me in my placements.  The first one I put in, I did it backwards because I did not check how the switch read.  Directions on how to use these things are not very good or non-existent.  So play around with them is important so you understand the functionality of them

 

They read either 0  or 1023 on analog pins.  You will need to understand how to hook them up to get them to read.  You will need a 10K ohm "pull down" resistor.  As you have only 2 wires coming out the switch and you will need power (red) - ground (black) - signal (yellow/blue/white - which ever you are using).  The pull down resistor needs to be positioned between the ground (black) and the signal wire.  The signal wire will connect to one of the analog pins on your micro-controller (I use arduino).  I have found these to work best where I am dealing with water volumes and the float can move freely with the water levels.  In my media grow beds I have moved to media probes made out of stainless steel 2" long screws and connected up the same way as the float switch.  I place them at the top and bottom of the grow beds and read them to determine when my values are opened and closed with the duration of water holding time which is dependent on crop - time of grow season - fish loading.  Hope this helps a little.

[Kobus Jooste]

Oh dear.  I thought these could operate as a normal contact switch - just splice them into the power supply of the pump and when they close the pump is on and when they open the pump goes off.  Do they not operate in that way?

Rik Kretzinger said:

I have found them to be reliable.  They take up little space and work great.  I like the 90 degree ones better.  As they are easier for me in my placements.  The first one I put in, I did it backwards because I did not check how the switch read.  Directions on how to use these things are not very good or non-existent.  So play around with them is important so you understand the functionality of them

 

They read either 0  or 1023 on analog pins.  You will need to understand how to hook them up to get them to read.  You will need a 10K ohm "pull down" resistor.  As you have only 2 wires coming out the switch and you will need power (red) - ground (black) - signal (yellow/blue/white - which ever you are using).  The pull down resistor needs to be positioned between the ground (black) and the signal wire.  The signal wire will connect to one of the analog pins on your micro-controller (I use arduino).  I have found these to work best where I am dealing with water volumes and the float can move freely with the water levels.  In my media grow beds I have moved to media probes made out of stainless steel 2" long screws and connected up the same way as the float switch.  I place them at the top and bottom of the grow beds and read them to determine when my values are opened and closed with the duration of water holding time which is dependent on crop - time of grow season - fish loading.  Hope this helps a little.

[Rik Kretzinger]

Kobus,

They work off 5v power, so you will need to run it through a relay to do the switching.

 

rik

[Kobus Jooste]

Thanks Rik.  I'll get someone over here to help me get all the parts together! Being colourblind, I never really got into the electronics side of most things and learn as I need to. Looks like there is a bit more learning coming my way.

[TCLynx]

There are simple mechanical float switches out there but they are a bit more likely to get fouled or tangled since the float has to be strong enough to push up a rod and flip a switch and big/heavy enough to pull the switch again when the tank drains down to the desired point.  I  have one that floats up and down in a "gravel guard" and it usually functions well but it has been know to get hung up.

 

Anyway, you can often find the switch/housing in the sump pump section of a big box store here.  The one I have actually came with a sump pump that has long since died but the switch actually plugs in and you plug the pump onto the back of the switch plug so I didn't even have to wire anything up for this one.

[Rik Kretzinger]

Kobus,

when you get ready I have all the information you will need on my blog listed under "Float Switch".  I also have everything you need to connect up the relay configuration there also.

 

Here is the link for the blog:

www.rik94566.wordpress.com

 

 

[Vlad Jovanovic]

Hi Carey,

What's the build quality/reliability like on their macros and sensors? (in your opinion). I was looking into some sort of basic automation for the GH as well as some motion sensor activated video blablabla... Their prices seem pretty cheap, which made me wonder how well their wares hold up through repeated winter/summer cycles?

Carey Ma said:

I have no idea about verticle level switches but I like using X-10 home automation. Simple, relatively non expensive and fully programmable.

[Harold Sukhbir]

Hi Kobus,

Maybe this DIY can help

http://reefworkshop.com/DIY_floatswitch1.htm

http://www.otherpower.com/float_switch.html
Kobus Jooste said:

Thanks Rik.  I'll get someone over here to help me get all the parts together! Being colourblind, I never really got into the electronics side of most things and learn as I need to. Looks like there is a bit more learning coming my way.

[Kobus Jooste]

Thanks Harold.  I will have alook at these when the time allows.

Harold Sukhbir said:

Hi Kobus,

Maybe this DIY can help

http://reefworkshop.com/DIY_floatswitch1.htm

http://www.otherpower.com/float_switch.html
Kobus Jooste said:

Thanks Rik.  I'll get someone over here to help me get all the parts together! Being colourblind, I never really got into the electronics side of most things and learn as I need to. Looks like there is a bit more learning coming my way.

[Terri Mikkola]

Kobus, Make sure the float switch you purchase doesn't contain mercury. If the seal were to fail, you run the risk of contaminating your AP system with mercury.

[TCLynx]

Luckily I believe the ones pictured above use magnets but that is a good point Terri, make sure the switch is safe.