The Lie Detector only appeared in the episode "The Ed-Touchables". It was made by Edd with objects such as a toaster to determine if Jonny and Plank were lying. It's performance was slow and may not have adequately assessed the situation, but it reveals that Plank was lying about the missing items. Sensor wires are placed on the vital parts of the subjects face, such as the head, cheek, and tongue. The wires are connected to a toaster. When bread is deposited into the toaster, it powers up. After the subject gives a reply, the wires connected to the toaster somehow transfer their information to the toast. Edd interpenetrates the meaning of the toast and then pegs out his answer on the board.
- A Lite Brite Board
- A toaster
- A lightbulb attached to the toaster
- A bunch of wires
- Tape to hold the wires down
- A Slice of Bread
- A Reel-to-Reel tape recorder
- The Lie Detector is the first normal machine shown in the series.