DIY Auto Top Off - schematic and pictures

[Kam]

I have been designing this for about 1 week. I built is over the weekend and its working great. Below is the schematic. I don't have step-by-step pictures as I did things in a crazy order and that would be more confusing.



Parts List
~ 3 Float Switches (Floatswitches.net $6.00 each)
~1 Project Box (Radio Shack 270-1803 $3.69) Box measures 5L x 2.5W x 2D This box is a little tight to fix all the components into.
~ 2 12VDC Plug-in Relay with Socket (Radio Shack 275-206C $9.39 each) This Relay is more expensive than others I could have used, but by using a plug in relay, I can easily replace the relay if it goes bad, without having to unsolder and re-solder.
~ 1 12 Ft Light Duty Extension Cord (Home Depot $9.57) Could have used a less expensive 6ft cord, but opted for the Light Duty
~ 1 12VDC Piezo Buzzer (Radio Shack 273-059 $3.29)
~ 1 Green LED Assembly (Radio Shack 276-271 $1.99)
~ 1 Red LED Assembly (Radio Shack 276-270 $1.99)
~ 1 Orange LED Assembly (Radio Shack 276-272 $1.99)
~ 1 Panel Mount Size N Coaxial Power Jack (Radio Shack 274-1583 $2.59)
~ 1 Size N Coaxial [acronym:85a8710bc1="Direct current"]DC[/acronym:85a8710bc1] Power Plug (Radio Shack 274-1573 $2.59) Needed this because the 12VDC adapter I found in the junk drawer used an unusual connector.
~ 1 Phono (RCA) Jack (Radio Shack 274-346 $3.99) Package contains 3 panel mount jacks only 2 needed.
~ 1 Phone (RCA-Type) Plug (Radio Shack 274-319 $2.99) Package contains 4 plugs, 2 Red and 2 Black. Only 2 plugs needed.
~ 1 6-Position Female Interlocking Connector (Radio Shack 274-236 $1.99) See next item
~ 1 Male Interlocking Connector (6-position) (Radio Shack 274-226 $1.99) Used to easily disconnect the wiring from the LED lights in the panel from the wiring in the box.
~ 1 package 3/8" Grommets 5 pack (Home Depot $1.75) Radio shack sells a Grommet pack for $1.99 that has 7 each: 1/4", 5/16" ,3/8". 5 each: 7/16", 1/2". Pack of 31
~ 3 1 1/4" [acronym:85a8710bc1="Plastic pipe"]PVC[/acronym:85a8710bc1] Cap (Home Depot $0.51 each)
~ 1 12VDC Power Adapter (Found in junk drawer FREE)
~ A section of 1 1/4" [acronym:85a8710bc1="Plastic pipe"]PVC[/acronym:85a8710bc1] (Had some at home FREE)
~ Wire (Extra 18 Gauge Speaker Wire FREE)
~ Wire Nuts (Had some at home FREE)
~ Heat-Shrink Tubing (Had some at home FREE) Multi pack at Radio Shack (278-1627) costs $2.39
~ Crimp-on Butt Connectors (Had some at home FREE) Multi-pack at Radio Shack (64-3037) costs $1.69 - (5 for 22-18 ga.), (5 for 16-14 ga.). Pack of 10.

Tools
~ Wire cutters
~ Solder and Soldering iron
~ Drill bits and drill

Project total (not including tax): $78.72

Float switches in Sump


Auto Top off box mounted in custom Acrylic shelf


Right Side of Auto Top Off Box showing 12V [acronym:85a8710bc1="Direct current"]DC[/acronym:85a8710bc1] power port and three lights on the top.


Left Side of Auto Top Off Box Can see the RCA ports on the bottom where the cables for the float switches connect.

[mp3z24]

i like it... let us know how it works once you have it all filled up.

you must be an engineer. that looks like something i would make for my tank. (especially the schematic )

just a thought, but you may want to add a stilling tube to the float switches. if there is a lot of turbulence on the surface of the water, you may have the switches turning on and off constantly.

~mike

[Kam]

Thanks!!

Yep, an Engineer I am.

All float switches are about 1" into a piece of 1.25" [acronym:2b006641fb="Plastic pipe"]PVC[/acronym:2b006641fb]. In my short term testing they worked great eliminating any on/off cycles from surface agitation. If for any reason I need additional length, I will slip a 1.25" coupler on the bottom.

[czcz]

Kudos!