| 摘要 |
<p>PURPOSE:To select the best internal circuit corresponding to an input signal and to obtain a wide-range high-sensitivity characteristic by providing a switching circuit which detects the amplitude of an input signal and selects the internal circuit consisting of an amplifying circuit and a peak sense circuit in combination according to the amplitude. CONSTITUTION:Amplifying circuits A1 and A2 amplify and send the signal from an input head H to peak sense circuits P1 and P2, which detect its peak. Further, the signal is processed by an arithmetic circuit M1 and its output signal is outputted from a terminal 6. An internal circuit switching circuit CH slices the level of the input signal with a certain voltage and performs switching to the best combination of the circuits A1 and P1 or A2 or P2 according to whether or not the voltage is exceeded or not. The signal from the head H is normally larger and larger in amplitude as the frequency is higher and higher, but the optimum circuit can be selected by providing the circuit CH. Consequently, the high-sensitivity characteristics can be obtained over the wide range of the input signal frequency.</p> |
