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CANT FIGURE THIS OUT!!

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Brad E

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hi folks. I really could use your brain power because mine obviously isn't working. Beware my experience with electronics is limited so please be patient.

I'm trying to run three mini water pumps with certain times. I want to push a singe button and have all 3 sequences run.

1. I need the first pump to run for 30seconds then stop. I'm actually guessing 30seconds. I need a potentiometer in the circuit so I can play with the times until I dial it in. so maybe 10-60seconds with pot. Im trying to fill a container and am not sure how fast it will take.

2. the second pump I need to remain off for 5min 30seconds, then on 1s ,off 1s for 5 ON cycles. so total time duration for this would be 5 min 40 seconds? Astable 555?

3. the third pump needs to run for same as the second pump. Im assuming I can run pump 1 & 2 in series off the same circuit to achieve this.

Since my pumps are variable, I can run the circuits off 2.5-6V. I can really use your guys help coming up with the proper schematic to solve this problem. Thanks for your help and patience. please be gentle.

pump details:
  • Voltage: DC 2.5-6V
  • Current: 130-220mA
 
IMHO, the best way is to just get a microcontroller and program it to control the pumps in any pattern you may want. If you don't like the pattern, it'll be easy to change.
 
I need all three to start and end at the same time. the whole sequence would last for 5min 40 seconds. well I guess it would really be 5 min 39 seconds.
 
for step 1, im thinking I should use a 500Kohm potentiometer, a 100uF cap, and wire a 555 in mono. maybe put a 10Kohm resistor inline with the POT.
 
thanks northguy, what do you suggest for a person with a limited budget?

You can get a small PIC or AVR microcontroller for less than $1.

You will need some sort of programmer to program it. But you only need to buy it once, then you can use it with all your projects.
 
Your timing regime could be accomplished with cascaded 555 timers (2 quad NE558Ns). Cheap but considerable construction needs and not as precise (or as expandable) as using a uController (e.g., Arduino Uno - $25 plus a few NPN transistors, resistors, etc). Learning curve with both.

Arduino IDE is free.
 
I need all three to start and end at the same time. the whole sequence would last for 5min 40 seconds. well I guess it would really be 5 min 39 seconds.

What kind of pumps? Do you have a data sheet or model number?

eT
 
I need all three to start and end at the same time. the whole sequence would last for 5min 40 seconds. well I guess it would really be 5 min 39 seconds.
After this is completed, the sequence will repeat once you push the button again, right?
 
Do a google for 'handy little relay' they do versions that are timers and probably up to doing what you want with a little wiring.
 
you can make a oscillator with pot for variable frequency and devide it and use counters to trigger on and off the motors as you want, cheap and you can acheive better accuracy. I still didnt get your full timing sequence, if you can sketch a timing diagram for all three opration it will explain better, i can draw the circuit for you.
 
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