Bill,

I just had a thought, I will need to test the pump for current under normal working conditions wont I.

What I mean is, it will draw more current pumping water (with load), instead of just running in free air. (pumping air , no load)??

 

Sounds right, yes.

 

I have been working on a circuit board layout for a few days, I will post it up when I am finished and you can have a quick look, I think it's ok sa far.

Hopefully amending the circuit board design for optical sensor wont take to much work.

 

Bill,

I tested the pump on my old systen I designed (same pump I would be using) and it is reading 1.20amps (reading taken from the + & - in terminals on the relay, also when I connect the meter to the + &- on the relay, the pump stops working, is this simply because the adaptor is borderline on the 1200ma's??

I have not actually wired this all up to the protoboard yet, I have just tested the pump on it's own, apart from the adaptor being borderline, should this pump be okay to use???

 

Sounds good. Does it pump water like you want?

The power supply should be rated double that at least, it will increase the lifespan of the components.

 

The pump works fine, but I have not connected it through the proto type board yet.

I was wanting to see what you thought about the power supply, it must be pretty close to the limit, will it be okay to wire it all together for a test run?

I will get either a 2a or 3a rated power supply, for the finished unit.

 

3A is better than 2A, but the power supply should be OK.

 

Hi Bill,

Longtime not "speak" hope you are well.

I have been busy soldering the circuit to a prefboard.

I have it all done except, I have struck upon a problem, you may know exactly whats wrong, me on the otherhand I am stumped at the moment.

Q1 has negative voltage on G & S when the unit is switched on no voltage on D, and the float is open (just power on state, float open circuit) but when I close the circuit, I get no voltage on Q1 D (middle pin of Q1) the pump run led does not light up, I cannot figure out why as I think I have soldered it exactly the same as the prototype board (obviously not as it was working)

Everything else seems to work, not checked to see if the pump runs yet as it is still in use on my other unit, but I assume as the LED does not light up, the pump would also not run.


PS, If I touch both the gate and the drain with my meter test probe, the Pump run LED lights up.

Have I blew the Mosfet??? I did read they are easy to damage, due to static electricity!!!!


Thanks again

Graham

 

Well would you believe it!!!!!!!

Seems to have been my wiring again, I left the project for an hour and a bit, went back to it and 1 of the float wires had came out!!! put it back to where it should have been and it's now working fine, I assume I had 1 of the float wires in the wrong place which was making something do or not do something it was suppose to.

Well the main thing is it's work, I have soldered my first every PCB and it works, you could say am well chuffed.

Have to change a few of the wires out, as I used the wrong gauge and they cant carry enough amps to run the pump, it's nearly done.

 

Hi Bill,

I have not forgotten about this project, just been really busy lately, I have now got it all soldered up, still need to order correct power supply and pump.

How are you?

What would be involved in using an Optical sensor instead of the float switch?

Thanks

 

Pretty much the same, except for one extra electrical lead. No problem with the delay, my work has gotten wierd (6-7 days a week). Oh well, least the money is good.

 

HI Bill,

Longtime no speak, How is your work? Still busy?

I have a quick question for you, I have soldered it all up onto a prefboard, all was working fine, but I needed to make some adjustments.

now when I close the float, the pump on led lights up, but when I then open the float, the light stays on?? Have I got a stray connection somewhere?

If I leave the float connected after the set time, the power cuts of to the pump and the buzzer sounds, just that the float is at present not controlling the pump, the timer is, if you know what I mean.

I assume it's a simple stray connection, and I have near pulled all my hairy out looking for it, have you any Idea what maybe causing this??

Thanks

 

Are you using the optical sensor?

This is something new, right? It was working?

 

No still the same float switch, yes it was working, I think it's my soldering I have a bad connection or a cross wire somewhere.

when I activate the float and then break it, the pump run LED stays on for whatever the pot is set at, I have looked and looked again, and I still can't see why.

I don't understand why the pump run LED is staying on, as when the - voltage is removed by the float switch it should go out, but it's not??

 

OK, troubleshooting mode.

This is the last rev. from post #85...

Use a DVM to measure these voltages.

1st. Make sure the voltage at the float switch / R1 goes between +12VDC when the float is open to 0V when the float is engaged.

2nd. If this happens, then make sure pin 5 of the IC times for whatever duration. In other words, it goes high for the expected amount of time the pump will run.

Let me know how this goes, and I'll figure out what's next.

 

Hi Bill,

I get a reading of 1.93v when between R1 and the float switch when the float is open, testing the float at point A19 and R1 at the side that is connected to the + side.

Not sure whats going on? I am assuming as I have 1.93v with the float open, I have a voltage crossover somewhere!!

 

Pin 5 goes low when the pump is on??

 

Bill,

It works as it should, except the float is not stopping the pump when opened!

 

OK, has this board ever work since you transfered it? You may have swapped some resistors, say R1 and R3 or R5. R1 is brown black brown, and the other two are brown black red.

 

Yes it has worked fine, I used the wrong guage of wire and changed some out, this is why I am thinking soldering error.

It has been my fault all the other times.