connecting 12v water pump

do i need some sort of chip between my arduino uno and the 12v water pump.?

Pretty sure you'll need an amplifier, as an arduino isn't capable of sourcing the current and voltage required for a water pump.

In the past I have used a relay

A relay or transistor is the norm, if you use a relay you'll almost certainly need a transistor anyway (to drive the relay).


Rob

There is a great "instructable" on this topic !

With a complete instruction on how to calculate things for your specfic situation......

But the water pump is 12v 3A.
I bought NTE152
Will that take care of it?

latif:
But the water pump is 12v 3A.
I bought NTE152
Will that take care of it?

Too marginal of current flow and current gain at 3amps. I would look for something with more grunt.

I like logic level power N-channel mosfets for switching higher currents:

Lefty

lol, I already bought it! And I don't have time to order online!
So just want to make sure this will do the job!

Try it and see. You will need a heat sink and a reverse connected diode across the motor terminals to protect the transistor when you stop the pump.
jack

for the reverse diode! does it need to handle 3A or higher!!

No, something like a 1n4002 to 1n4007 series or similar for this application, rated at 100volts+ and 1 amp, since all it's doing is "quenching" the reverse voltage kick when you switch off the power.
jack