| 摘要 |
PURPOSE:To prevent a pulse width of a line signal from being made narrow by employing a diode biased forward as a generating element of a control voltage controlling a transistor(TR) interposed between choke terminals. CONSTITUTION:A TR interposed between choke terminals is operated in an active region with respect to a DC and even when an AC signal is superimposed onto the DC, the TR is controlled so as not to give effect onto a collector current of the TR. A diode D biased forward is employed for a control voltage generating element 1 to generate a control voltage controlling the TR. With a DC applied to the electronic choke circuit, a voltage VD across the diode D is inputted to a noninverting terminal of a differential amplifier circuit 20 and fed to a base of the TR in a voltage follower as a control voltage Vb. Captions R1, R2 are resistors. Since no capacitive element is employed in this circuit, the width of the line signal is not made narrow. |
