Hopefully you will bear with me, I am rubbish at reading diagrams

The bottom float should control the system fully, turning the pump on and off, correct?

Should the bottom float go faulty and the timer has ended it's timed cycle, the pump shall stop?

The top float is only going to be used in the extreme condition of the bottom float welding closed and the timer overunning or going faulty, the 2nd float shall open and stop the pump, this is all to stop lots of freshwater getting pumped into a saltwater tank

 

I've been pretty tired, I completely missed the aquarium reference.


OK, next attempt:

1. Normally open float switch closes for lack of water.

2. Relay turns on pump, also timer starts.

3. Water level raises, switches float switch open, timer keeps pump going.

4. If timer times out, and float switch is still closed, which keeps the water flowing, the alarm goes off.

5. The alarm resets if float switch open and timer off.

Here's the schematic...

So, a thought occurred, why not use an inverted coke bottle filled with fresh water. A tube can keep the bottle hidden.

 

3. Water level raises, switches float switch open, timer keeps pump going.

When the float switches rises and opens the circuit I want the pump to stop, the timer cannot govern the amount of water pumped as this will change, the timer is there to cut the circuit should the float stay closed after the set amount of time.

4. If timer times out, and float switch is still closed, which keeps the water flowing, the alarm goes off.

If the timer times out and the float is still closed, it would need to cut the pump and sound the alarm

The coke bottle would need filled everyday, I want to use a large 25ltr container and fill and forget for about a week.

 

OK, we're getting there.

The float switch overrides the timer for pump on.

The timer overrides the switch for pump off.

If the float switch is on, and the timer is off, an alarm sounds.

 

OK, we're getting there.

The float switch overrides the timer for pump on.

The timer overrides the switch for pump off.

If the float switch is on, and the timer is off, an alarm sounds.

Yeah, nearly there

The float turns the pump on and off in normal operation, the float really runs the system totally.

The float when closed also starts the timer, now, should the float stay closed after the timer has timed out, the timer cuts the circuit even tho the float is still closed.

If the float is closed and the timer has timed out, this shall sound an alarm and cut the pump.

The float switch could be closed and the timer timed out because the container holding the freshwater has run out, the alarm sounding will draw my attention to this, so the timer serves 2 functions, a problem with the float, or the water container has run out.

So what I was trying to say above minus the waffle I went of on is,

Float drops, starts pump and timer, water into main tank, float rises, cuts power to pump, timer resets. (this is normal operation)

Float drops starst pump and timer, timer times out before float rises, cuts power to pump, sounds alarm. (this is fault or no water operation)

 

I see an opportunity to get rid of the relay altogether,but I will need the specs for the pump first.

You can make this alarm as obnoxious as you would like, a sonalert is loud, but the sound doesn't travel through doors well. I'm showing an LED for the alarm, but it can be much brighter. As with the pump, I would need specs to make sure the driver is powerful enough to handle it.

 

Anyhow, this is what I have at the moment...

 

Bill,

The pump is rated @ 15-24w 12v DC the aadaptor I was going to use was a 240v AC to 12v DC adaptor rated @ 2a (2000ma)

Thanks again for all your help it's very much appreciated.

 

What kind of alarm are you thinking of. It can have a flashing light and siren, or a simple little LED and sonalert. If the latter, that part of the circuit is finished.

 

I was thinking of a simple buzzer (fairly loud), nothing fancy, could even have a flashing light on it, but not neccessary

 

Bill,

For reference if the driver you are reffering to is the 12v dc adaptor I would be using.

I am currently using the same pump on the system I have at the moment, but that 12v dc adaptor is only rated @ 1300ma from memory.

 

OK, I think this may the final version. I found some concept problems that I fixed.

Now comes the fun part, what part of the world are you in? This controls the parts you get to some degree.

The other question is how you plan on building it. I get the feeling you don't have any background in electronics at all, this is not quite a beginner project. Do you have someone you are going to ask to help build it?

If you are going to do it yourself, I would suggest using a protoboard. I don't normally suggest this, they are moderately expensive (around $7), but I can help you lay it out if we go this route.

 

Bill,

I live in the UK, Bonnie Scotland to be more precise.

you are right, when it comes down to it I would say my electronics expertise on this kind of stuff is about 0.

To be honest I can follow your diagrams to a point, but all these symbols confuse me.

I am going to do some reading up on it, I enjoy building stuff and really like a challenge, I feel this will be exactly that.

I work for an Electrical wholesaler, so I have access to all these parts, but we mainly sell items that are for wiring houses and any other buildings.

The next bit i can figure out is where I would get a PCB as such to make this unit.

I would probably use, www.rapidonline.com or RS Components for the parts, but not sure on where I would get the board bit.

 

I've kept the parts simple. I'd suggested using the protoboard, mainly because it is easy to document (take another look at my protoboard drawings in my 555 experiments to see what I mean).

 

Bill,

I can't see the relay in the design above?

Excuse my ignorance if it's there but I am not to sure on the symbols.

I am away to draw up a parts list and will post it to see if I have everything needed for this build.

Thanks for doing this for me.

 

I kicked it out of the ballpark. Read post #26. I used a MOSFET, it will require a heatsink but I eliminated the relay.

Want me to lay out a protoboard? Since this is a brand new design it may require tweaking.

 

Bill,

This was much simplier in my head, MOSFET???

If you have the parts and it wont cost you anything I would be obliged, If you don't, I will get a list of parts put up, so you see them and can tell me I have got all the wrong bits.

Just out of curiousity, say coming from limited electronics background, I do learn quickly once I have done it, and from what I have posted, do you think is this out of my league?

Also is this expensive to build, I looked at some of the parts and they are pennies, but it does look very technical, which usually means expensive.

I really want to build this, but fear I may be running before I can walk in the electronics field.

Thanks

I kicked it out of the ballpark. Read post #26. I used a MOSFET, it will require a heatsink but I eliminated the relay.

Want me to lay out a protoboard? Since this is a brand new design it may require tweaking.

 

Look at my experiments. It is easier if you have a plan to follow. With the exception of the float switch most of the parts can be had from Radio Shack, including the protoboard. I have to tell you though, you can get the parts cheaper from almost anyone else.

 

Would you be able to put up exactly what I need Bill?

I have a feeling you could reel them off just looking at the diagram, I can only see what I think is 2 x 556 timers some cacpacitors and some resistors, not sure about this MOSFET thing.

If this is turning out to much hassle for you I understand, I think I am jumping in at the deep end.

I see from your profile you are a Tech, what exactly is that? as you seem to really know your stuff.

 

No problem, but since this drawing is a bit more complex it will take a while longer. I'll come up with a parts list too. Certain items, such as your pump, power supply, and float switch will be assumed.

A tech is short for technician. I can do some design, and almost all building and troubleshooting of electronics. My AA degree in college was for engineering technology, which is more of a hands on field than straight engineering. Add 30 years experience to that and you have my background.

A MOSFET is a kind of transistor. It has some advantages over its older cousins, but they are getting to be pretty old tech themselves.

The drawing I will provide will show orientations and whatnot.