| 摘要 |
PURPOSE:To switch a magnetic head by conducting the 2nd common contact and the 3rd independent one when a group of the fourth independent contact and the 2nd common contact and that of the 1st common contact and the 1st independent one are conductive with the conduction of the 1st common contact and the 2nd independent one. CONSTITUTION:Since transistors Q2 and Q1 are interrupted and a transistor Q3 is conductive at recording, the plus side of the coil L2 at the other side of a rotary transformer RT1 is grounded through a resistance R6 and the transistor Q3. On the other hand, since the transistor Q1 is interrupted, a relay coil L5 will not be excited, and accordingly the common contact P1 of the 1st changeover switch SW1 is conducted to the 1st independent contact q1. Moreover the 2nd common contact P2 of the 2nd changeover switch SW2 is conductive to the fourth independent contact q4. At reproduction, the transistor Q2 is conductive, whereas the transistors Q3 and Q1 are interrupted. The attitudes of the 1st and 2nd changeover switches are the same as the recording. |
