The perfect diy float switch..

[reefsahoy]

Heres the perfect float switch you can make for about $2. You'll never have to worry about it ever getting stuck or ever having to clean it. Ive used one now for 15 or so years and not once have i had problems with it. Im now going to start a nano, so i built a new one and figured id share the idea.

All you need is
1. Silicone glue
2. Ice cream stick
3. Wire
4. Cigar container. (I found mine on the ground while walking the dog)
5. Mercury switch


I figure with pictures it'll be self explanitory, so here goes.

Glueing switch to the stick.

Installing it into the cigar container.

Silicone the opening water tight!and the completed

This switch actually floats in water and The wire coming out of the switch is piched between the glass in the aquarium or sump by using a glass cleaner magnet. You simply adjust the magnet height to determine the water height so when evaporation starts the switch will tilt turning on the ato or alarm, once new top off water enters the aquarium, the switch floats back turning off the ato or alarm!

Because mercury is liquid state it's impossible to jam or mechanically fail so forget all those other types of switches that may fail or need maintennance.

 

[reefsahoy]

Switch in action

Cheers

 

[Paul B]

Thats exactly what I have been using for decades. They never fail. I have one in my RO/DI resovour which stops the water flow when it is full.
When I worked as a construction electrician in Manhattan I would take the old thermostats for the mercury switches. I used to have dozens of them. Great little device.

 

[mayjong]

can you even get merc switches anymore?

 

[reefsahoy]

can you even get merc switches anymore?

Why would you think you cant get one? Definitely local here for like $2 http://www.brelectronic.com

 

[AquamanE]

REEFSAHOY- next time im in the market ill reach out to you. Im not that handy. Heck ill give you $20 for your $2 investement, LOL!!!

 

[rovster]

I still don't understand how it works. I guess I need to understand how the mercury switch works. I assume it has to do with the orientation? When it moves, the mercury inside moves triggering the switch? Cool DIY nonetheless

 

[treetopflyn]

I still don't understand how it works. I guess I need to understand how the mercury switch works.

Ditto

 

[jimbo78]

REEFSAHOY- next time im in the market ill reach out to you. Im not that handy. Heck ill give you $20 for your $2 investement, LOL!!!

Maybe you could come up with some cigar tubes....

 

[billsreef]

I still don't understand how it works. I guess I need to understand how the mercury switch works. I assume it has to do with the orientation? When it moves, the mercury inside moves triggering the switch? Cool DIY nonetheless

Pretty simple actually. There are two contacts sealed inside the switch with the mercury, which being a liquid metal is conductive. When the switch is in the down position, the mercury rolls away from the contacts and breaks the circuit. In the up position, the mercury rolls back onto the contacts closing the circuit. This gizmo is nothing more than a DIY version of bilge pump float switch, just cheaper and fun to make

 

[reefsahoy]

REEFSAHOY- next time im in the market ill reach out to you. Im not that handy. Heck ill give you $20 for your $2 investement, LOL!!!

No problem, just let me know if u need one. If anyone here on rc knows a cigar smoker they will probably have those containers. You can probably use one of those test tubes that comes with salifert water test kits.

 

[reefsahoy]

I still don't understand how it works. I guess I need to understand how the mercury switch works. I assume it has to do with the orientation? When it moves, the mercury inside moves triggering the switch? Cool DIY nonetheless

Mercury is a liquid conductor. The mercury will always flow to lowest point and two contacts will get submerged in mercury making/breaking the connection.

 

[Paul B]

I use mercury switches all over my house for all sorts of things. They never wear out and last forever. Just don't eat the mercury.

 

[jonnyu]

Now that's a great idea

 

[samaytt]

Good idea, but with my luck one of the kids will pull the magnet off to clean tank and there goes the tank.