Title:
COIL CIRCUIT FOR ELECTROMAGNETIC WAVE RESONANCE ABSORPTION MEASURING INSTRUMENT
Document Type and Number:
Japanese Patent JP3181076
Kind Code:
B2
Abstract:
PURPOSE: To quickly attenuate residual vibration after excitation, and to high sensibility execute reception by varying Q by providing a series-parallel resistance circuit between a switch for interrupting a high frequency power source at the time of reception and a high frequency power source.
CONSTITUTION: The coil circuit consists of a high frequency power source 3 for excitation, a resonance circuit 10 including the excitation and reception combined coil of an electromagnetic wave resonance adsorption measuring instrument, a first switch S1 which is provided between the high frequency measuring instrument, a first switch S1 which is provided between the high frequency power source 3 and the resonance circuit 10, and interrupts the high frequency power source 3 at the time of reception, and a second switch S2 which is provided between the resonance circuit 10 and a high frequency amplifier 4, and interrupts the high frequency amplifier 4 at the time of transmission. Also, between the high frequency power source 3 and the switch S1, a series-parallel resistance circuit consisting of resistances 20 (Rs), 21(Rp) is installed. In this case, Rs and Rp are the values of Rs=SRo and Rp=PRo, when the internal impedance of the high frequency power source 3 is Zo (Zo=Ro), and also, S and P are S=1/(P+1).
Inventors:
Yasuo Nagasawa
Application Number:
JP23110491A
Publication Date:
July 03, 2001
Filing Date:
August 20, 1991
Export Citation:
Assignee:
Hitachi Medical Co., Ltd.
International Classes:
A61B5/055; G01R33/36; (IPC1-7): A61B5/055; G01R33/36
Domestic Patent References:
| JP467844A | ||||
| JP1214355A |