We now know how redstone circuits work, and we know about all the power sources in the game. Finally, let's look at the devices we'll be powering.
Doors, trap doors, and gates
All of these doors can be triggered to open or shut, using redstone. The iron door can only be activated using redstone, which stops villagers from opening the door and zombies from breaking them down.
Redstone lamps
A big bright light source which can be turned on and off through redstone power.
TNT
An explosive block that blows up and destroys anything within its radius. It can be triggered with redstone - at which point, you have about four seconds to duck and cover!
Note block
This block plays a musical note when it first receives power. Which means it's best used with a button or a pressure plate. Hit the block to cycle through its notes, and then it will play the last note when it is next powered.
The block beneath the note block will also dictate the sound it plays.
Minecart rails
If you place a rail next to a curved rail, like shown above, and then provide redstone power, the rail connection will switch orientation. Which is pretty handy.
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A powered rail, connected to redstone, will give a moving cart a big push in the right direction. When set up properly you can make a cart move forever. Weee! A powered rail that is not connected to redstone will make the cart stop.
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A powered activator rail will make a player or mob fall out of a minecart, if they are riding one and go over the rail.