| 摘要 |
PURPOSE:To apply a wide-band signal transmitting circuit to a digital VTR, etc., which records and reproduces high-resolution video signals, by using an amplifier whose input impedance becomes almost zero on the secondary side of a rotary transformer. CONSTITUTION:When the 2nd amplifier 7 whose input impedance becomes almost zero is connected between a rotary transformer T and rotary magnetic head H, no resonance occurs, because a short-circuited condition is produced due to the existence of the 2nd amplifier 7 even if the floating capacity C of the transformer T exists. Since a treble cut-off frequency is determined by the impedance of a signal source, therefore, the frequency becomes far higher than the highest frequency to be handled and the treble cut-off frequency is practically nothing. When the 2nd impedance is almost zero, a bass cut-off frequency also becomes very low because of the low impedance and it is easy to lower the frequency below the lowest frequency to be handled. Therefore, a circuit which satisfies the frequency characteristic required to the signal transmitting system of a digital VTR can be realized easily. |
