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[Reply #15 on:]

Hello again everyone,

I just bought my first Arduino Uno board.
(no shields yet.  Also, it's the one with the Atmel chip in the "cradle" (name??).  Not the new one that has the Atmel chip soldered on (SMB?))

Anyway, I got a couple of other items, yet I'm at a loss as to how to connect all this.
I think I'm missing various components before making this work.

There are three main reference links I'm using:
High-Power Control: Arduino + N-Channel MOSFET
Using a transistor to control high current loads with an Arduino
How do I connect a relay?

As a review:
I don't need to control the speed of the DC motor... just give it 12v power.

Parts I have:
- Arduino Uno board
- TIP120 Darlington Transistor
- SPDT PC Relay (12VDC coil, Rated 10A at 120VAC/24VDC)
- Random assortment of 1/2 Watt resistors

My main questions are:
What diagram should I follow?
and
Power supply to the washer pump motor.

I can nail down the power supply to the Uno fine.
Yet, for the washer pump... ??

Today in Radio Shack (yes, I know) I saw a transformer.
I believe it was 120VAC --> 12VDC 3A.
Will this work?

I need to check the washer pump to see how much will the little motor draw (I'm not sure how many Amps).

Can I make it work with what I've got?

Thank you very much to everyone!!

[Reply #16 on:]

I just built this with a breadboard

(source reference link)

Yet I'm using the TIP120 I have, instead of the RFP30N06LE MOSFET the guy is using.

Will... this work?

[Reply #17 on:]

Using the mosfet as shjown in that diagram, you should connect a 100 or 220 ohm resistor between the Arduino output pin and the mosfet gate. If you substitute a TIP120 for the mosfet then you MUST connect a resistor between the output pin and the TIP120 base terminal. 1K will do. The disadvantage of using a TIP120 is that it has a voltage drop of around 2 volts, which means it will get hot and need a heatsink unless the motor current is small.

[Reply #18 on:]

Thanks a LOT for the feedback and help dc42!
Greatly appreciated!


I just went to Radio Shack and bought a IRF510 Power MOSFET N-channel 60 volt.

Will this work if I follow the guy's directions (as per the image in the post above)?

Thank you very much... this electronics area is amazingly interesting to me.

I love mechanical stuff, and now this... there are analogies all around.
Looking forward to building more interesting things!
=)

[Reply #19 on:]

Unfortunately, the IRF510 is not a logic level mosfet, it's designed to be driven from 10V on the gate instead of the 5V that the Arduino provides. With 5V on the gate, I wouldn't ask it to pass more than 500mA. Look for a logic-level mosfet instead.

Unfortunately, Radio Shack appears not to stock any logic level mosfets in its stores. You're not alone, here in the UK, Maplin is equally useless.

[Reply #20 on:]

Ok.
I just ordered 5 RFP30N06LE from SparkFun.com

As soon as they arrive, I'll give it a go.

I will update this thread ASAP.
Thanks!! =D

[Reply #21 on:]

The RFP30N06LE finally arrived!!
w00t w00t!

Will start working on this right now, and update in a little bit =)

[Reply #22 on:]

It works!!!!!!
w00t w00t!!!