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Controlling 5 mini pumps individually is there something better ?

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Sailorb

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After reading several examples of various 555 timer circuits i'm wondering if there is a better way of doing it. Here is the situation, I need to individually turn on 5 small pumps each from its own trigger but space is limited so I wanted to make a single board powered by 12v dc , when triggered it would stay on for 10 sec then stay off for 60 before resetting to wait for the next on signal. I'm using windshield washer pumps and they burn out after running for more than 12 sec or so and need 60 sec to cool down. Which is the best direction for something like this?
 
Perhaps you could use a circuit based on the one I posted in post #36 of the thread 'Help with pump' in this forum.
 
Yes that looks like what I need but setting Timer limits? and Im doing it on the cheap of course, and it would have to have 12v pw instead.
PumpTimersX4.gif
 
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setting Timer limits?
In that circuit each pump has its own pair of pots. The upper pot (1meg) controls the 'on' time (up to ~60secs) and the lower one (500k) the 'off' time (up to ~30sec). The pump supply can be 12V instead of 24V. If you already have 12V then you don't need the 7812 regulator but you may need extra decoupling components to smooth the supply for the CD40106. Bear in mind that is a circuit for simulation purposes rather than a full constructional circuit. Although Schottky diodes are shown from the FET drains to +V you will also need them from the FET drains to ground, to suppress below-ground voltages when the pumps switch off. The circuit is modular so can easily be extended to deal with a fifth pump. The IC has 6 gates inside, so one of the 2 spare gates can be used for pump #5. You will probably find cheaper suitable alternatives for the MOSFETS and Schottky diodes shown. The circuit will also need modifying to incorporate the triggering you mentioned. What will trigger the circuit? Push-buttons?
To save space you can replace the pots with suitable fixed resistors (values determined by experiment).
 
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Ok if I catch what your saying the pots are interchangeable to give me the 10sec on 60sec off i need then once the resistance is determined on the prototype then test with an similar resistors. Good to know the IC can handle 6 of these circuits that would be my next question if I need to expand it further. As for the power what decoupling components would you suggest? As for the trigger, Im still playing with some options, but I need to pull liquid from the containers so it is most likely going to be a float switch or continuity sensor so Im probably going to need a signal voltage from this as well, to apply to the trigger. and as far as the FET drains to ground I would just put a diode on each ground for each circuit right?
 
the pots are interchangeable to give me the 10sec on 60sec off
Yes.
As for the power what decoupling components would you suggest?
In the attached, Rx, Cx and Cy are the extra decoupling components. Cy should be connected as close as possible to the IC pins.
as far as the FET drains to ground I would just put a diode on each ground for each circuit right?
See attached.
 
Ah very cool, I will order the components and bread board this for testing this week. Thanks very much I will post my progress with it. next week :)
 
I'm using windshield washer pumps and they burn out after running for more than 12 sec or so and need 60 sec to cool down. Which is the best direction for something like this?

So why not just buy one good 12 volt pump that can run continuously instead of doing all the fiddle and fudge work? From doing a quick search I found that 5 generic windshield washer pumps costs about 2 - 5 times what a simple continuous duty 12 volt mini pump costs.

Just for reference, **broken link removed** 30K+ hr run time for $22.41 including shipping.

What exactly are you pumping and for how long? :confused:
 
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Where would I interrupt the circuit for the fill level on off switch
It depends on the type of switch you have.
A pump can be switched off by either :-
shorting the input of the respective CD40106 gate to the +12V rail, using a low-current switch, or
disconnecting the pump from the +12V rail, using a high-current switch (able to handle the stall current of the pump).
 
Do L2 L4 L6 & L8 go on pcb or external coil? What should the value be? Where are L1 L3 L5 & L7? Where is U1? Any specific value for D1 D2 D4 D5 D7 D8 D10 & D11?
 
Do L2 L4 L6 & L8 go on pcb or external coil?
Neither. They are just part of the model for a pump motor. The contents of the dotted rectangle represent the motor's inductance and resistance.
Where are L1 L3 L5 & L7?
Nowhere.
Where is U1?
U1 is a CD40106 IC containing 6 gates, of which 4 (labelled U1a, U1b, U1c, U1d) are used in this simulation.
Any specific value for D1 D2 D4 D5 D7 D8 D10 & D11?
1N4148 or any similar general-purpose silicon signal diode (not power diode).
 
So once again what are you pumping and how long do you need to pump it? :confused:

Reason being most window washer pump motors are very short service life units. Even when run at short intervals to prevent overheating they will still wear out after a few hours total run time being they have very short service life bushings and brush/commutator assembly's.

Basically even with cycling through 5 motors to limit overheating issues you still wont make it very far time wise before the motors themselves are physically worn out maybe a day or two at most.
 
Im pumping the well of several filter units that are in series and the condensate fills in each one at different rates so I need to recycle it back to the reservoir since this is on my truck it will freeze when off in the winter if there is any water in it. Since Im doing this on the dime the windshield pumps are cheap, accessible and 10 sec is long enough to empty each of the wells on the filter at least in a few cycles , plus I like to learn this kind of stuff its very cool.
 
Hi sailorb,

just one hint concerning the pump motors.

They are heavy duty motors throwing a water lance more than five yards with the right nozzle fitted to the water hose.

I needed a pump to fill an overhead water tank which was used to gravity fill the water dispensers for my rabits some 40m out in the back garden. (There was a 150Ah lead-acid-battery taking care of lighting and watering.)

I faced the same problem as you were since the pump motors get hot after two to three minutes of usage and finally burn up.

If you can work with less water volume flow you might think about DC-motors as used in ship models. They run for hours since they are constructed for continuous use.

I used a windshield wiper motor and mounted motor and pump on a piece of plywood with a cardanic connection between them.

The unit worked like a charm for many years.

Boncuk
 
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yea, why not one continuous pump pumping in a loop with valves for the x outlets you need unless there is something we don't know?
 
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