| 摘要 |
<p>The invention comprises a velocity sensor (10, 30, 50, 60, 70, 110). The using differential flux splitting, and by sensing changes in flux, common mode effects are removed. A permanent magnet (17, 33, 55, 65, 71, 131) is used to create a flux field, and multiple return paths are used to split the flux. A plurality of pole pieces (20-21, 39-40, 58-59-66-67, 72-73, 111-112) simultaneously move an equal amount in relation to the return path for differentially varying the amount of flux carried by each return path (13-14, 34-36, 52-53, 63-64, 73A-B and 75A-C, 115-117), to thereby induce a differential voltage in secondary coils (15-16, 37-38, 56-57, 68-69, 80-83 and 90-91, 140-143 and 150-153). The pole pieces and return paths are overlapped by an amount to ensure that one may move relative to the other a limited extent in directions not parallel to the sensitive axis without effecting a change in the net overlapped area, and the coils are arranged in series-connected, oppositely wound pairs so that common mode error signals are cancelled.</p> |
