Different Types of Empty Minecart Detectors (Minecraft)
Channel: Frumple
Date: 18/12/2011

Download the Minecraft Savefile here: http://www.mediafire.com/?bqockvm0ios8rvz

Oldschool:

= Uses an old minecart glitch booster to guide cart over a stone pressure plate.
= Example: MRT Station v2.1: http://www.youtube.com/watch?v=ZTKn8gKUIXI

+ The only cart detection method before detector rails introduced in Beta 1.5.

- No longer works in Beta 1.6 or later.

Gravity-Based:

= Uses sloped rail so that occupied carts clear the hill, while empty carts fall back down.
= Example: MRT Station v3.0: http://www.youtube.com/watch?v=kNhqEHGXdBs

+ Only uses rails. No redstone or pistons needed.
+ Simple to build.

- Requires cart to make at least a three-block climb.
- Must wait for empty cart to clear before sending another cart.

Timing-Based:

= Occupied carts are fast enough to clear the detector, empty carts are too slow and are switched off.
= Example: Video by MinecraftAddict: http://www.youtube.com/watch?v=YN_TRmUcGyk

+ Rail is entirely flat.

- Requires precise timing and consistent incoming cart speed.
  (Not for people with very little patience)

Track-Jumping:

= Cart falls on a stone pressure plate, and then forced back on to the track by some mechanism, usually a piston.
= Example: Reddit post by JonnyRobbie: http://www.reddit.com/r/Minecraft/comments/l3191/detector_rail_for_occupied_minecart_only/

+ Rail is entirely flat.

- Track-jumping might be jarring for some riders.

Sloped Detector Rail:

= Invented by MrFroZen23
= Video by SethBling: http://www.youtube.com/watch?v=WnweUQm6gyI

+ Very simple to build.
+ Very compact.

- Requires cart to make a one-block drop.
- Carts must travel at full speed before reaching the detector rail.
- Might be a bug that may be fixed in the future.

Plate-on-a-fence:

= Invented by ProfessorPoopyPants (+ others)
= Video by ProfessorPoopyPants: http://www.youtube.com/watch?v=-gFD7mx1VRM

+ Simple to build.
+ Compact.

- Requires cart to make a one-block climb.
- Obstructs the cart rider's view.

Other detectors that people have submitted to me after I posted this video:

666mayhem666's Passenger Detection System:
http://www.minecraftforum.net/topic/578825-10x-minecart-passenger-detection-system/