发明名称 |
Speed detecting apparatus |
摘要 |
In a speed detecting apparatus for detecting the rotational speed of a rotating body mechanically coupled thereto, an encoder generates one cycle of a sine-wave signal each time its angular position of rotation changes by a predetermined unit amount. A zero-crossing pulse is generated at each zero-crossing point of the sine-wave signal generated from the encoder, and the phase angle of the sine-wave signal is detected on the basis of the zero-crossing point of the sine-wave signal generated from the encoder. In a high speed range, the rotational speed is detected on the basis of the ratio between the number of zero-crossing pulses and the time interval between a first one and a last one of the plural zero-crossing pulses. On the other hand, in a low speed range, the rotational speed is detected on the basis of the combination of the number of the zero-crossing pulses appearing within a predetermined period of time and the phase angle of the sine-wave signal.
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申请公布号 |
US4839834(A) |
申请公布日期 |
1989.06.13 |
申请号 |
US19870002202 |
申请日期 |
1987.01.12 |
申请人 |
HITACHI, LTD. |
发明人 |
OMAE, TSUTOMU;MATSUDA, TOSHIHIKO;MIYAHARA, YOUJIROU;KAMIYAMA, KENZO |
分类号 |
G01P3/489;G01P3/42;G01P13/04 |
主分类号 |
G01P3/489 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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