Redstone · Mechanic · Java & Bedrock
How to Use a Redstone Torch
A redstone torch is power that is always on, until you power the block it sits on, when it flips off. That flip is the basic NOT gate, the building block of nearly every redstone circuit.
Three ways to use it
1
Power source
On its own a torch is always on. It powers redstone dust right next to it at full strength and weakly powers the block directly above it.
2
Inverter (NOT gate)
Stick it on a block and power that block: the torch switches off. Input on means output off, which is the single most-used logic gate in redstone.
3
Signal upward
Stack torch, block, torch, block up a wall to make a torch tower that carries a signal straight up, something plain dust cannot do.
Watch for burnout

If a torch is forced to switch on and off too quickly, like in a fast torch clock, it burns out: it puffs smoke and goes dark until the input stops. To build fast clocks, use repeaters or observers instead and keep torches for steady inversion.
Quick answers
What does a redstone torch do?
By default it is on and acts as a power source: it powers adjacent redstone dust at strength 15 and weakly powers the block above it. Attach it to a block and it also works as an inverter.
How do you make a NOT gate?
Place a redstone torch on a block, then feed power into that block. When the block is powered the torch turns off, so the torch output is always the opposite of the input. That is a NOT gate.
How do you send a redstone signal straight up?
Build a torch tower: a torch, a block above it, a torch on that block's side, another block, and so on. Each torch re-powers the next, carrying the signal up a wall that plain dust would lose.
Why did my redstone torch burn out?
Switching it on and off too fast, like a tight torch clock, makes it burn out. It puts off smoke and goes dark until the input stops, which protects against runaway loops.
How do you make a redstone torch?
One redstone dust on top of one stick in the crafting grid makes a single redstone torch.
Does a redstone torch power its own block?
It powers the block above it weakly and the dust beside it strongly, but it does not strongly power the block it is mounted on, which is what lets the inverter trick work cleanly.