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Great idea @ProtoFire, let's show the kids at home how they can properly use a series resistor as a current limiter. In this example we'll use a potentiometer to limit the current of an LED. By tapping on the pot in the workspace, it will become highlighted and make it available for adjustments. After the component turns gold, look to the bottom of the screen for the toolbar, and then tap the wrench icon that's on the left. Notice another tab pop up just above the wrench? That tells us specifically what value we're about to change. *Special Note- If the pop up tab is highlighted gold, the selected component has more than one value available to adjust!* In this case there are two: total resistance of the potentiometer itself, and the potentiometer's wiper position- which raises resistance on one side while lowering it on the other.
Now lets try it out! Adjust the wiper position to allow more current to the LED below. LED's can be adjusted the same way as the pot, but here I've left the default values in place. So swing the wiper around until you reach 20mA through the LED, then make a note of how much resistance is shown on the pot, and how much voltage is coming from the source. All the of those values working together are Ohm's Law in action!
Wondering what the other LED is for? It's an unfortunate, but necessary sacrifice to show what happens if there's no series resistor in place- poor little LED... =^(
Ok time to get to it! Have fun, change values around and learn what you can!..
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