DIY Auto top up

[gturnbull]

Well after a few requests to post a, How did I do it guide for my Auto top up unit, I have decided to put up a thread on how I built it, this version has been modified

This unit is relatively cheap to build, a bit of electrical knowledge would be beneficial, (if in any doubt, get a qualified electrician to look it over)

First you need to gather the parts required;

1 x 12v DC multi voltage adaptor 1200ma, pref with Polarity reversing funstion (Argos, Tesco or Ebay)
3 x Float Switches (Part No.61-1305)
1 x 12v Dc Relay & Base (DPDT) (Part No.60-1610 & 60-1770)
1 x Red 12v DC indicator light (Part No.42-0940)
1 x Green 12v DC indicator light (Part No.42-0941)
3 x 2.5mm DC power connecter sockets (Part No.20-1096)
1 x 2.5mm 5a DC power connector socket (Part No.20-0880)
3 x 2.5mm DC power leads (Part No.20-1020)
1 x 5a Miniature toggle switch (Part No.75-0125)
1 x Toggle switch rubber boot (Part No.75-0120)
1 x Plastic Enclosure (Part No.30-3364)
2 x Small pots (Asda)
1 x 12v DC Submersible pump (Ebay)
1 x Suitable water container (the pump I used shall fit inside the neck of a 25ltr drum)
1x Small cable gland 5-7mm (Part No.04-0275)
1 x Length of heat shrink sleeving (Part No.03-1105)
1 x Strip of 5amp connector strip (Part No.21-1688)
2 x Mtrs of 0.75mm flex (outer insulation stripped off to leave the brown and blue insulated cables)

All the Above Parts are available from www.rapidonline.com, unless otherwise marked.

Tools required;

Small power drill
5mm, 6mm, 8mm & 13mm drill bit
Small terminal screw driver
Soldering Iron & Solder
Wire strippers
Stanley knife
Hot air gun, hair dryer or lighter (to shrink the sleeving)


To start lets get all the soldering done;

Take the 3 x 2.5mm DC Sockets,

Hold them so the pins are facing you (pins should be in 9, 12 & 3 Oclock position) use the pins @ 9 & 12 Oclock.

Step 1 :Take the first Connector and solder a long length of wire to the pin @ 9 Oclock, then slid a length of heatshrink over the wire and over the pin and shrink this in place, then take another length and solder that to the pin @12 Oclock take a length of heatshrink and slid that over that wire and shrink it in place, now take another length and slid it over the same wire ready for the next connection.

Step 2: now take the other end of the wire you just soldered onto the pin @ 12 Oclock and connect it to the pin at 9 Oclock on to the 2nd of the connectors, now slide the other length of heatshrink that you placed onto the same wire and shrink that in place, now solder another length of wire onto the pin @ 12 Oclock on the 2nd connector, slid a length of heatshrink onto this wire and shrink it in place, again put another piece of heatshrink onto this wire for the next connection.

Step 3: Now solder the wire from the pin @ 12 Oclock on the 2nd connector onto the pin @ 9 Oclock on the 3rd connector, solder a longer length onto the pin @12 Oclock and you should be left with something like this. NOTE I used blue wire as I did not have enough brown, brown wire would be the correct colour to use as you are switching the live with the floats)

Step 4: The connector for the main power in (2.5mm 5a Socket), solder a length of about 6-8 inches of blue wire onto the pin @ 9 Oclock & a length of brown onto the pin @ 12 Oclock (for the eagle eyed you will notice I used the wrong pins, but that was sorted and I forgot to take another pic)

After you have done the above, you want to connect the on/off switch.

 

[gturnbull]

To do this take the brown wire from the above connector and slid a length of heat shrink onto the wire, then solder it to the small pin on the back of the switch and shrink the heat shrink over this connection, then take another length of brown wire and connect it to the other pin, again sliding a length of heat shrink over the wire and shrink it in place, then connect the brown wire from the switch and the blue wire from the 2.5mm connector to a piece of 5a connector strip, see pic below for what it should look like this when it is fitted into the enclosure. (Dont worry about the 2 blue wires coming out the other end of the connector strip, I will be coming to them later in the build)


Select your location on the enclosure for the 3 float sockets (6mm Hole), the cable gland for the pump wire (13mm Hole), Main power connector (6mm Hole), on/off switch (6mm hole) and the Indicator lights (5mm hole) drill the holes accordingly, Now these can all be fitted into the enclosure. NOTE The Indicator lights are best fitted into the enclosure lid before you make an connections on them as, they get pushed through from the front & if the connection of the wires is to large they will not fit through the hole, also remove the nuts & the serated washer from the switch, fit it in the enclosure, replace the serated washer and use the small rubber switch cover to hold it in place.

Now to connect up the Indicator lights, solder a length of blue wire onto the Silver Connector on the lights and a length of brown onto the Gold connector, do this for both them both, then slid a length of heat shrink over the wire and shrink in place.

You should now have something like the picture above & below, (Ignoring the 2 blue wires in the above pic I mentioned previousy)

Next get the 3 float switches ready,

First to configure the Float switches, this can be easily done by removing the float from the switch and turning it round, squeeze the 2 prongs in @ the bottom of the shaft and the float just comes off, may need a lttle wiggling.

The small white float has a magnet at the top of it (you can see it in the above picture, the small black ring inside the whole of the white float), for the 2 inside the return or main tank, the magnet should be at the top of the float and for the 1 in the top up tank the magnet should be on the bottom.

The 2 that go inside the return chamber or main tank need are set to close when they drop, the high level float is always closed as it is always in the dropped position (until opened by a high water level), the low level trigger float is also set to close when dropped, as this will tell the system that the water level has dropped in the sump/tank and requires topping up.

The float inside the top up tank is set to open when the float drops, as this will tell the system that there is no water in the top Up tank and break the circuit, thus not allowing the pump to operate, even if the low level trigger float has dropped and trying to operate the pump.

 

[gturnbull]

Next get the Snail/Algae guards ready,

Take the 2 pots and drill an 8mm hole to accept the float switch in the bottom of the pot,then drill numerous small holes in the pot to allow for the air to escape, drill the holes at the very top and bottom on the sidewalls of the pots, NOTE If you do not drill the holes this will cause an airlock and not allow the float switch to operate properly.

You can drill holes in the lid and keep the lid on the pot or just remove the lid completely.

Remove the nut on the float switch, fish the wires through the hole, then replace the nut, they have now got protection from snails, algae etc.

The third float switch does not require protection as it is in the Top up chamber and now life or algae should be in there to block it up.

Now take the 3 x 2.5mm DC Power leads & Snip off the Small pastic shroud that comes attached to the lead.

Now slip a small length of heatshrink sleeving over each individual wire, now solder 1 of them onto each of the float switches, it is not important what way round the wires go, then cover with the heatshrink sleeving and shrink into place.

 

[gturnbull]

Note; If you have it, take some aquarium safe silicone and put some over the joints of the float that is going in the bottom of your top up tank, just to be on the safe side, or use a longer length of heatshrink on this joint.

After this has been done, that is all the soldering that is required, and you are nearly finished the Top up Unit :applause:

Now to put it altogether :dance:

You need to get the enclosure and the lid & the Relay base

1) You need to cut 2 lengths of blue wire and 1 length of brown, make them fairly long.

2) Get the 5a connector strip that you connected inside the box earlier on, take the 2 blue wires you have just cut and blue wire from the red light that you installed earlier and connect them into the blue side of the connector strip.

3) Take the brown wire that you just cut and the wire from 1 end of the float connectors (mines is in blue wire) and also the brown wire from the red light, and connect these into the brown side of the connector strip.

You should now have something that looks like the pic below,

4) Now get the Relay base, the numbers in brackets refer to the number on the Relay base, each hole has 2 numbers so will you help identifiy what wire goes where.

Take the brown wire that you have just connected into the connector block and attach it as shown to the Relay base (11 or 1), now take the wire from the other end of the float switch connectors and attach it as shown (A1 or 2) do the same with the 2 blue wires that you just connected from the blue side of the connector block and connect as shown (1 into A2 or 7 & 1 into 21 or 8 ) it sounds complicated but it's not when you have the wires and base infront of you.

See the picture below for clarification,

4 more wires to connect and you are done :applause::dance:

5) You need the pump for this step, feed the wire from the pump in through the cable gland you installed earlier, you should now have something that looks loke this,

 

[gturnbull]

Connect the brown wire from the pump & the brown wire from the green light into the relay base as shown (14 or 3) They both go in the same terminal on the base.

Connect the blue wire from the pump & the blue wire from the green light into the relay base as shown (24 or 6) They both go in the same terminal on the base.

Now plug in the Relay into the base, it has an alingment pin, so make sure it is lined up, don't force it.

check all the connections are tight, no loose or bare wires hanging out, fit it all inside the box, making sure not to chack any wires, Thats it done :thumbsup:

Brackets for floats:

You can attach them to you tank by whatever means suit you, but I made little Acrylic Brackets with a couple of holes on the back that sticks to the tank, this helps seure it, by making sure some silcone ooze's out the holes when you are attaching them.

NOTE If after you have connected the unit up the lights do not come on, but the pump works, you need to reverse the Polarity on the Multi voltage adator, refer to your adaptor instructions to find out how to do this.

Disclaimer, You undertake this project at your own risk, I accept no resposibilty for any loss or injury to anyone or anything.

 

[cdness]

Nice build!

What is relatively cheap? Do you have an estimate of the final cost of the build?

 

[gturnbull]

well it cost me about £55 so that would be about $90

Bearing in mind I am converting from pounds to dollars, you can probably buy the parts cheaper over your side of the pond