Minecraft – Please explain why this redstone minecart-loader works

minecraft-java-editionminecraft-redstone

See attached images. I am proud that I was able to build this tool to make a chest-minecart pause while it gets loaded from a hopper, and when the hopper is emptied, the powered rail beneath it powers again and the minecart travels off. This construction is working perfectly. I admit I learned most of it from a video and slightly rearranged it.

The basic function is: When there is nothing in the hopper, then the various blocks cause the powered rail to have power. But if there is something in the hopper, then the various blocks cause the powered rail to lose power, so the minecart stops. It works great.

But, my problem is that I don't understand the logical sequence that makes each of the parts work in sequence!

Can a redstone genius out there please:

Look at the two attached images (one of the rail receiving power because the hopper has no items in it, and one where the rail is not getting power because the hopper has items)
Clearly explain the logical chain of events that makes it work. For example:
- The hopper has something in it, so it causes a redstone charge to come out of it into the block next to it.
- The redstone comparator then causes XXXX… this makes the YYYY…

Best Answer

Matthew Sheeler bubster20's answer is correct, but I wanted to expand a bit more on what each piece is doing here.

Comparators "read" the container behind it (a container being anything you can open and place items in, such as a hopper, chest, etc.). If there are any items inside the container behind, it sends off a redstone signal.

So, in the circuit above...items enter the hopper from the water stream. The comparator sees this and becomes powered, powering the block it is pointed into. This turns off the redstone torch on the other side of that block, which stops powering the redstone dust, repeater, and the block the repeater is pointed into, which the powered rail is drawing it's power from.

When the hopper is emptied, the reverse happens. The comparator stops sending a signal because the hopper behind it has no items, unpowering the block the comparator is pointed to, causing the redstone torch to turn back on. This powers the redstone dust, repeater, and the block the repeater is pointed into, which in turn powers the powered rail.

Related Solutions

Minecraft – How to power a row of droppers efficiently from side or bottom

The most resource efficient way I can come up with to power a horizontal line of droppers is this

enter image description here

with the redstone line on the left being connected to a clock. This works because the repeaters strongly power the dropper they are pointing into causing the droppers to the left and right to be indirectly powered.

The vertical line of droppers is powered as described in this Youtube video, with a comparator being used to send a (inverted by a redstone torch) signal to a vertical stack of redstone torches powering repeaters pointing into every 2nd vertical dropper.

With regards to the specific situation you are in the most resource efficient way to get the mobs from the exit of the spawner to the 'home' area would be to bring them up high enough using a mob elevator (a 1x1 tube filled with alternating water blocks and signs will cause the mobs to swim themselves up to the top) to a point where they can be dropped down the required number of blocks.

The only pitfall with this type of system is ensuring that the mobs fall a consistent distance everytime. All that is required to do this is to ensure that the water stream at the top of the elevator is set up like this

XXXXXXXXXX
X        X
X~~~~~S  X
XSXXXXX  X

(where ~ = water and S is a sign)

So that mobs get pushed into the drop shaft by other mobs pushing against them instead of directly by a water stream.

Minecraft – What caused the TNT Minecarts to explode

It would appear that if 2 TNT minecarts run into each other on a curve with sufficient speed, it will set them off.

Step 1: Build a loop. Step 1

Step 2: See if Minecarts explode when place next to each other. Step 2

Nope, looks like this is safe.

Step 3: See if Minecarts explode when across from each other. Step 3

Nope, this seems fine too.

Step 4: Try to make minecarts explode on straight sections. Step 4

This never set it off (this picture is different because I tried many times to figure out where it was exploding).

Step 5: Make minecarts crash on a curve. Step 5

Ah ha! This resulted in an explosion. Boom Boom

This did not happen every time the minecarts collided in the corner, so this seems to be somewhat randomly caused.

Further Science

Does it need to be 2 TNT carts? Extra 1

No! In fact, regular Minecarts seemed to set off the TNT more frequently. KaBOOM

Also, chickens are friends, not ~~food~~ fireworks. I like chickens Eddie!

Best Answer

Related Solutions

Minecraft – How to power a row of droppers efficiently from side or bottom

Minecraft – What caused the TNT Minecarts to explode

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