发明名称 |
Linear power control for ultrasonic probe with tuned reactance |
摘要 |
A driver system for an ultrasonic probe using a tunable inductor in series with the piezoelectric crystal excitation transducer in the probe. The bias current through this flux moduation coil is controlled by the system such that the inductance of the tunable inductor cancels out the capacitive reactance of the load impedance presented by the probe when the probe is being driven by a driving signal which matches the mechanical resonance frequency of the probe. The resulting overall load impedance is substantially purely resistive. The system also adjusts the frequency of the driving signal to track changing mechanical resonance conditions for the probe at different power levels. This method of operation insures substantially maximum power transfer efficiency and substantially linear power control over a range of power dissipation levels. The system determines the mechanical resonance frequency by sweeping the drive frequency and monitoring the drive current to determine the frequency at which the drive current is a maximum.
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申请公布号 |
US4954960(A) |
申请公布日期 |
1990.09.04 |
申请号 |
US19870035128 |
申请日期 |
1987.04.06 |
申请人 |
ALCON LABORATORIES |
发明人 |
LO, YING-CHING;ZAMBRE, SAMUEL;ESCORCIO, TOLENTINO |
分类号 |
A61B17/00;A61F9/007;B06B1/02 |
主分类号 |
A61B17/00 |
代理机构 |
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主权项 |
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地址 |
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