Self-contained detector device for checking information recorded on a carrier

摘要

A self-contained detector device for educational or amusement purposes cooperates with conducting and non-conducting zones of a carrier. The detector is in the form of an elongated hollow body with a reading or detecting head projecting from one end. The head is rigidly mounted on a printed circuit board that travels slidably in the hollow body. When the detector is in use on the carrier, pressure causes the head and board to slide up into the body and close a spring switch, energizing a detecting circuit on the board and coupled to the head. The head can favorably be formed as a stack of alternate conducting and non-conducting sheets. The non-conducting sheets can be of an elastomer.