The present invention relates to a work-indicating unit of a magnetic control exercise apparatus. A plurality of circuit board sets are positioned around a flywheel. Each circuit board set has several sensing elements and light-emitting elements (e.g. monochromatic or polychrome LED). Each sensing element...http://www.google.sh/patents/US6626804?utm_source=gb-gplus-sharePatent US6626804 - Work-indicating unit of a magnetic control exercise apparatus
