Hello. Short story, making an irrigation system using arduino and I just started doing the wire diagrams.
The Arduino will be powered by the 12v socket plug and the pumps from a stand alone battery.
On atleast one of the pumps I want to add a small voltage regulator to regulate the output from the battery to adjust the pumps speed.
My question: Do I have to use the -in and -out's?
In my mind I think I need to connect the regulator as in picture nr 2.
But is it possible to connect it like in picture nr 3?
Does the current have to go back into the regulator after it has passed the motor, or can it be sendt right to ground after having been inside the water pump?
You’re asking for an answer to the classic x-y problem
That scheme will not work, you cannot apply PWM into a power supply module. Why do you think you need to regulate the voltage to a lower value?
I think you need to start at the beginning and master some basic concepts first. Have you done the basic Arduino examples with a motor and a potentiometer using PWM to control the speed of the motor?
BTW, the use of the 1k and 2.2k gate resistors will cause switching speed troubles. 100-150 ohms is more like it. You should also have a 10k resistor from the output pin of the Arduino to ground to prevent false triggering. Connect like this:
The pump is a bit strong and by regulating the voltage with the regulator it can pump at a perfect rate for the plants in question.
I was under the impression that one could send a signal from the digital pin to the mosfet and then have it open its gate for the current from the battery, and then power the motor. Didnt know that the PWM pin only supplies PWM signals.
Hello Digitidope,
You have an answer in that in this case you don't need the converter*, but I think your question still deserves answering so you know for future and for the benefit of anyone else reading this wondering the same thing. The clue to the answer is in the word 'circuit'. Electrical circuits are just that, paths for electricity to circulate around, back to the beginning, so with that in mind the answer is yes, you do, so the electricity can get back to where it came from, the converter. You should also use the input 0V for the input and the output 0V for the output and not mix them up because mixing them up means the ground currents for input and output are not separated, possibly leading to noise.
