Hello
I'm trying to create a garden watering system controlled by Arduino. I have an Uno and a 12-volt pump.
Can I run the pump from my Arduino board with the relay below from the SparkFun inventor's kit? Do I need something else? Thank you
Relay SPDT Sealed
Single Pole - Double Throw (SPDT) sealed
This relay's coil is rated up to 12V, with a minimum switching voltage of 5V. The contacts are rated up to 5A (@250VAC, 30VDC).
5V DC SPDT Relay
Rated up to 5A
Fully Sealed
Spec of the watering system?
Do I need something else? Thank you
The key element needed is a 12vdc voltage source able to supply the maximum current needs of the pump motor.
Lefty
Might need a transistor to drive the coil's relay too.
Maybe also a diode across the relay coil to limit any voltage spike when you turn off the transistor.
Joe
I have a power supply for the pump- what I'm not sure about is can I switch the relay directly from an Arduino pin?
Am I missing a step between the Arduino pin and the relay? If it's a transistor, what kind?
Or is Arduino able to work the relay without any other device?
(I made a crude diagram and attached it.)
Here is a circuit design that will drive a 12volt relay coil via a transistor switch under arduino control. Just wire the relay coil to where it shows a solenoid coil.
Thanks for the advice everyone
Are you just going to turn the pump on and off, every few minutes? Or will you want to vary the speed of the pump?
How big is the pump, as in how many Amps it will pull?
It sounds like you have the answers you need. But I've been doing a lot with controlling automotive relays using the Arduino. Some circuits are more efficient than others. As noted in the notes for the circuit Retrolefty posted, the transistor there will need a heatsink. There may be a better choice if, as AWOL suggests, you give us some specs.
If you are all set, of course, no need for more info.
