user3320: I want to drive my model trains (märklin) with my arduino UNO, it requires 32 watt (0-12/24v, 2A MAX(changes))
This is Direct current
How can I amplify the output of the arduino to get my 32 watt?

user1585: You certainly can. For relatively small amplifications, you can use transistors. MOSFETs are similar and work well for larger solid state amplification. If all you need is to turn power on or off (no switching faster than ~20Hz) a relay is you best bet, but most standard ones take more power than a raw arduino output can provide so you have to buy one for this purpose. They are all easy to use, for the most part just plug in ground, power, signal, and signal out. You can look up any of these for more details on use, it should not be hard to find.
The easiest pre-built solution is something like this relay board: http://www.sainsmart.com/arduino-compatibles-1/relay/arduino-pro-mini.html

3320: <p>I want to drive my model trains (märklin) with my arduino UNO, it requires 32 watt (<code>0-12/24v, 2A MAX(changes)</code>)
This is Direct current</p>

<p>How can I amplify the output of the arduino to get my 32 watt?</p>
 1585: <p>You certainly can. For relatively small amplifications, you can use transistors. MOSFETs are similar and work well for larger solid state amplification. If all you need is to turn power on or off (no switching faster than ~20Hz) a relay is you best bet, but most standard ones take more power than a raw arduino output can provide so you have to buy one for this purpose. They are all easy to use, for the most part just plug in ground, power, signal, and signal out. You can look up any of these for more details on use, it should not be hard to find.</p>

<p>The easiest pre-built solution is something like this relay board: <a href="http://www.sainsmart.com/arduino-compatibles-1/relay/arduino-pro-mini.html" rel="nofollow">http://www.sainsmart.com/arduino-compatibles-1/relay/arduino-pro-mini.html</a></p>
