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12v water pumps on/off running in sequence? Answered

Hello everyone.
I am trying to create a demonstration of my waterproofing products. As it stands i have a single water pump inside a 25x25x25 clear acrylic cube. At the moment they are either on of off. I have 3 of these in total. See attached image.
What i am trying to achieve is the pump to come on for an amount of time (roughly 2 seconds) then off for an amount of time (roughly 2 seconds) then repeat the cycle on loop.

What I would like is to have the ability to change how quickly or slowly the cycle loops (longer ON duration etc) and also which pump activates first and in which order. 

The pumps are UK plugs adjustable from 3v - 12v which changes the litres p/hr 

I've done some research but not sure if arduino will do the job? I'm complete novice so your help and advice would be greatly appreciated.
As much detail of the items required and where to source in the UK would be amazing.


If your in the UK go for the Picaxe microcontroller - cheaper and easier to programme for what you want


Use relays to turn the pumps on and off.

Manual 3 shows the required interface circuit


typical programme:

Assumes relays connected to pins 1 - 2 and 4 (pin 3 is an input only)


high 1 'turn output 1 on

wait 2 'wait 2 seconds

low 1 'Turn output 1 off

wait 2

high 2

wait 2

low 2

wait 2

high 4

wait 2

low 4

wait 2

goto start 'goto the start to do it over again

Thank you guys. Will look at both options! What actually do i need to purchase to make it all work? Is there anywhere that sells this sort of thing off the shelf?

Thanks Jay we are based in Tunbridge Wells but ship worldwide. Look at www.liquiproof.co.uk

Worls only permanent, invisible, ecofriendly, odourless nonflammable footwear spray!

A Picaxe08M starter pack - This will give you the download cable as well as a neat PCB to build on. £15 but parts are reusable. less if you discount the VAT


4 x 1K resistor - few pence

4 x BCX38C transistor - 38p each

4 x 5 volt relay from Rapid on line 88p + VAT


Down load the free program editor - The rest I have done for you.

Circuit below.

If your willing to buy a few resistors and a bit of perforated PCB (from rapid) you can avoid the expense of the starter kit but you still need the down load cable which is £11+ VAT I think so you may as well have their board which is easy to use.

picaxe pump control.jpg

Thanks again Rick. I have just purchased the picaxe and the relays and transistor however there are about 1000 different 1k resistors. How do you know which one to use? Also how will i learn which one is best for future?

Will this set up enable me to vary the on/off sequence?

If this is a question fro me then the answer is Yes - The wait command is in seconds. You can set it to anything up to a max of 65.

Of course you can use serial wait commands to get longer.

Over a long time periods - many seconds this isn't accurate to the second but is fairly stable.

PM me if you have any more questions.

It doesn't matter a lot. The difference is the wattage 1K is 1K .

You can use 1/4 watt resistors for this job- They are actually only there to protect the output of the picaxe from excess current flow.


0.72 p for 100.

Resistors have 2 characteristics (+ the material they are made from) - Resistance and wattage.

Watts = Volts x Amps. So you need to know how much current will flow through a resistor to judge the wattage, When in doubt use a 1/2 watt - Your unlikely in normal use going to exceed that.

Ahhh cool, I know Tunbridge Wells, a friend used to work in the Mexican restaurant.

If you want the fast, easy but expensive method, Steve's suggestion will get you going fastest. If it's commercial the cost probably isn't an issue and the cost will be offset by the setup time for a beginner. The way you program a PLC like Steve linked to is usually graphical, so it's drag and drop boxes, connected by wires for simple things.

If you want cheap but big learning curve, get a microcontroller like the picaxe or arduino and learn to program it. You'll need other hardware like relays, transistors and diodes plus a bit of time to learn some very simple programming. If you choose the second the important bit is the electronics surrounding the microcontroller.

Thank you Steve. I can't seem to click that link so i searched RS online and the millennium 3 is discontinued?

I am also a complete beginner here so what exactly is this and what does it do? Will it come with intructions on how to connet it all up?

Its a "PLC", a programmable logic controller. You can make the outputs switch over as you want, you can make the outputs timed, all sorts of things.

You need a 88970045 4 output, 8 input box £121.00

programming lead 970109 £85.00

Everything you need is in a nice little case, it needs 12V in, your pumps go on the relays, which are also built in. You have a small LCD display and some buttons. You can program it in an hour or two to drive your pumps. Drop me a PM if you need more programming help.

You can go the pixaxe route, but it will need boxes, power supplies and a lot of your time.

Try E. Preston's in Manchester for it, that's who I buy mine off


Ask for Peter Buckley, and tell him you spoke to Steve Taylor at Ravenfield

Thank you all for your support and guidance. Its all a different language to me but i am willing to learn. Went for the Picaxe in the end as seems very interesting. I'll download various manuals and how to guides and hopefully get what i am after.

Thanks again.

You could build a liner counter like the one in this instructable only three stages instead of six stages.


Instead of driving LEDs you can drive the pump motors like the motors this Instructable.


And a veritable clock like the one in this Instructable instead of driving the clock with IR LEDs and Sensors.


On the 555 timer if change the 4.5 uF 16 volt capacitor to a larger capacitor say a 10 or 47 uF capacitor you can increase the clock pulse times to seconds or minutes.


Yes Arduino will do the job. It's overkill but easy to start with and there is a lot more support material for beginners than Rick's suggestion.

Your product looks interesting, where are you based?

I disagree about the support - Picaxe supply free PDF manuals and have an excellent forum that is very supportive of newcomers.

OK your not going to get libraries of routines but you don't need them - The prog below does exactly as asked - start wait 2 seconds stop.

The picaxe £1.80