| 摘要 |
PURPOSE:To eliminate completely the magnetized phenomenon of a control track head, by supplying a recording current having the attenuation of oscillation to record a signal, and to have the own AC demagnetizing effect. CONSTITUTION:When a negative pulse of input is supplied, a TR1 is turned off through a C1. A bias current flows to a TR2 through an R2 to turn on the TR2 just for a period equivalent to the width gamma of an input pulse. The collector of the TR2 is set at about -12V to charge a resonance circuit C2 and an L1. When the negative pulse period gamma is over, the TR2 is turned off with the area between the emitter and the collector of the TR2 set in an open state. Then the electric charge stored to the circuit C2 and the L1 cause the attenuated vibration in response to the own resonance frequency and the value of Q. Thus a signal having the burst type attenuation characteristics is obtained to be supplied to a control track head 5 in the form of a recording signal through coupling capacitors C3 and C4 in a recording mode. |
