Is this a good fail safe ATO float switch circuit?

[sushi]

This is no schematic or anything, just a very simple prototype drawing. All three switches will be off when they float. So it will only be a complete circuit when the water is not lifting any of the three floats.

Note: I will also having timing fail safes, this is just the float switch circuit.

String 3 sensors together, 2 low one high, in series. 
If one switches, circuit is broken. Pump will only fill if 5v input detected.


----------------------------------------top of tank

  -----------------------------------------------------  <--  +5v
  |                          high-switch---------------  -->  input_pin  
  |		          	|				
  |                             |
  |                             |	
  ---low-switch___low-switch____|

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~water level

[greg619]

You'll need relays because have inverted logic cases. Float switches only trigger one way (that I've seen)


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[sushi]

You'll need relays because have inverted logic cases. Float switches only trigger one way (that I've seen)


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I will use relays to turn on the pump, I am not sure how the switches work exactly. If they are not on/off but send a signal instead, I will just have one circuit per float switch but the same logic will apply.

[DaveMorris]

With the way you have it drawn, the bottom two switches will not do anything. Once the water level triggers the top float switch, that is the only one that will do anything. Float switches do not output any power and you should not run power through them. Any controller that will use them as a trigger does run a very small amount of DC through them, but it is minimal. The circuit just senses a closure of the float switch contact. Float switches can be ON when floating or OFF when floating. The movable donut part can be flipped over to change how the switch works.

What is it that you are trying to accomplish? If it is just to trigger your topoff pump, then I would get something like this:

Autotopoff.com

This one is even better. I use it on my tank and it is 100% trouble free:

Avastmarine.com

The Avast Marine one uses a rigid tube and is triggered on air pressure. No moving parts and nothing to wear out.

[sushi]

The way I have it is so that all three switches are ON when not floating. So if any switch floats, it will turn off and stop sending the signal back.

This is so that if both of the bottom switches happen to get stuck down even after the water level goes above them, the top switch will be the backup. So if the top switch floats, it will turn OFF and break the circuit if the bottom two fail to do so.

[sushi]

With the way you have it drawn, the bottom two switches will not do anything. Once the water level triggers the top float switch, that is the only one that will do anything. Float switches do not output any power and you should not run power through them. Any controller that will use them as a trigger does run a very small amount of DC through them, but it is minimal. The circuit just senses a closure of the float switch contact. Float switches can be ON when floating or OFF when floating. The movable donut part can be flipped over to change how the switch works.

What is it that you are trying to accomplish? If it is just to trigger your topoff pump, then I would get something like this:

Autotopoff.com

This one is even better. I use it on my tank and it is 100% trouble free:

Avastmarine.com

The Avast Marine one uses a rigid tube and is triggered on air pressure. No moving parts and nothing to wear out.

One thing I really like that avast has is that mechanical emergency stop valve. I wonder if I could finagle that into the back chamber on my nano cube. That would really give me peace of mind.

[crabbysd]

[QUOTE=sushi;953504]This is no schematic or anything, just a very simple prototype drawing. All three switches will be off when they float. So it will only be a complete circuit when the water is not lifting any of the three floats.

Note: I will also having timing fail safes, this is just the float switch circuit.

[CODE]String 3 sensors together, 2 low one high, in series.
If one switches, circuit is broken. Pump will only fill if 5v input detected.

Your over thinking it. Most pumps are 12v dc first of all. so youll have to run the controller as a relay its a lot of work,. it becomes board sends signal 3-5v to switch, switch opens sends signal to relay relay opens 12v to pump.

This is what I have in my 28g. buy it you will be happy. it fits the jbj perfectly
http://www.ebay.com/itm/Aquarium-Aut...item419998a91f
You will have to replace the powersupply with one that has higher amperage or you wont have enough head to get the water from the floor all the way up to the tank. unless the ato water bucket is higher than the floor.

add one of these one way check valves to the tank end of the ato fill line to avoid siphoning the tank back int the ato and onto the floor.
http://www.ebay.com/itm/2PCS-8mm-5-1...item4639cd4818
I finally bought one after making several.

how a switch works draw a 12 supply schematic, add a motor to the end of the circuit, on the neutral side of the circuit add the symbol for a switch. its that easy.
http://www.ebay.com/itm/Mini-Horizon...item2a49dcf6b1

Later you can add a controller and still use the existing hardware.

draw the same circuit add relay to arduino as a switch. youll add a second switch signal to the board only to alert you of overflow(cut off).

Mine has not blown up yet or overflowed.

[crabbysd]

ps
and dont use the bio balls. get some rubble from Chris at vets pets in el cajon. Get your live rock there too.
Go fill your tank.

[sushi]

ps
and dont use the bio balls. get some rubble from Chris at vets pets in el cajon. Get your live rock there too.
Go fill your tank.

Haha, thank you friend, you always have good advice about everything.

I will read over this later, now I am going to the beach!

[crabbysd]

Haha, thank you friend, you always have good advice about everything.

I will read over this later, now I am going to the beach!

Good thinking!!!!(dont bring anything back but memories)
Heres 2 last things

Temp controller
http://www.ebay.com/itm/Fahrenheit-1...item417e7b5173
the fan I used in my jbj
http://www.ebay.com/itm/Xscorpion-TF...item53fbdb2dc0

once you read the controller directions/ schematics its a basic model of the more advanced controllers only with more channels and parameters. Kinda what my daughter did in her arduino class but with a nice case and buttons.