| 摘要 |
PURPOSE:To supply operating power for a head amplifier for a monitoring playback head in a rotary drum, by obtaining electric power from the rotation motion energy of the rotary drum by an AC generator. CONSTITUTION:A rotary drum 2 having a rotating shaft 14 pivoted on a guide drum 13 by a ball bearing 15 is driven by a driving motor 16 to rotate. The rotary drum 2 is incorporated with a monitoring playback head and its head amplifier 12 in addition to a recording and playback head, and the signals of the recording and playback head and head amplifier 12 are coupled with external equipments through rotary transformers 6-8. The output of an AC generator 21 which has an armature fitted to the rotary shaft 14 and a field system fitted to a fixed member is supplied to the head amplifier 12 through a rectifying circuit and a voltage stabilizing circuit on the same substrate with the head amplifier 12 by a lead wire 20. |
