Is it possible to send a redstone pulse as a wire turns off?

I have a machine I'm trying to build that uses a timer and I'd like for something to happen at the very end of the timer running down after it has turned off.

The only way I can think to do this is to somehow build a machine that inverts the on circuit to power a piston and when the circuit turns off the piston retracts for a while and then powers on again.

  • 1
    So what you want to do is send a short pulse from a not gate, essentially... correct? – Unionhawk Aug 9 '16 at 20:36
  • @Unionhawk ah yes. I guess so! I hadn't thought of it that way. Is that easy? – Fogmeister Aug 9 '16 at 20:37
  • It shouldn't be that hard, I'll hop in a test world in a bit to get something worked out. – Unionhawk Aug 9 '16 at 20:37
  • 3
    The phrase you want to search for is "falling edge detector". – zzzzBov Aug 10 '16 at 0:26
  • Check out Mumbo Jumbo's videos... he has some really compact ones. youtube.com/watch?v=Ht6JPs2SlH4 – Nyerguds Oct 1 '18 at 16:07

As mentioned by @zzzzBov, what you are looking for is called falling edge detector. The wiki has a section on these, with multiple options to choose from, like these two:

Dust cut-off FED Repeater-lock FED

On the left, the sticky piston retracts the diamond block, allowing a signal to go through before the repeater turns off. When the power is turned on, the diamond block cuts off the signal before the repeater turns on.

The design to the right works using locked repeaters. When you unpower the input, the repeater on the right is unlocked just briefly enough to allow a signal through. On powering the input, the repeater is locked before it can change state.

Another option you have is to use a rising edge detector, also known as a monostable circuit, and invert the input using a redstone torch. There's plenty of designs available online.


If you're looking for an inverter, this is what you're looking for:

This inverter uses a redstone, a block and a redstone torch.

  • This will invert a signal but that's not what I'm looking for. I was looking for a pulse. I think I'll need and inverter though. Will have a look at the falling edge detector mentioned above. – Fogmeister Aug 10 '16 at 8:07

just make a monostable circet and then invert the connector

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