How do I increase the drive current from the arduino digital pins?

Question

I'm new to the Arduino (using the Leonardo). I am working with a heatplate that gets hot when you apply power to it.

When I use the 5V Vcc pin it works fine. But when I use the digital pins I don't get enough current.

Is there any easy way to increase the amps you can get from the digital pins?

Would somebody have a simple driver circuit?

Thanks for the answer. This is my setup. I don't know exactly how much current the plate needs to get a high temperature fast, but i'm guessing in the range of 0,5 A - 1 A.

So basically, I need to use the transistor as a switch and then use another power supply for the heatplate-thingy ?

EDIT This is a picture of how I planned to do the setup. Feedback is very much appreciated.

Answer 1

You will have to use a transistor to drive the heatplate.

Something similar to this:

^{simulate this circuit – Schematic created using CircuitLab}

Note that this is a simplified general circuit. Without knowing the specs of the load you are trying to drive, we can't specify which components to use.

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EDIT: Based on your info of the voltage of the load's supply and that you already have a TIP120 to switch its power, consider this circuit that I found in this site. As @Matt pointed, a flyback diode will not hurt anybody.

^{simulate this circuit}