| 摘要 |
PURPOSE:To prevent an error at reproduction from being increased by connecting an input to a circuit detecting whether or not a magnetic head is selected correctly not to a center tap of each magnetic head but to a connecting point between an electronic switch turned on at the reproduction and a resistor the other terminal of which is connected to the center tap via a resistor. CONSTITUTION:When a magnetic head coil is selected correctly at the write, one of two center tap voltages is O(v) and the other is +Vc(v). A voltage V1 at a connecting point between a resistor 22 and the electronic switch 9 is O(v) and a voltage V2 at a connecting point between a resistor 23 and the electronic switch 11 is +Vc(v). Thus, a voltage V0 at a connecting point 19 between resistors 15 and 16 is +Vc/2(v). Since the V0 with the magnetic head coil selected correctly is large and the V0 with >=2 magnetic head coils selected is small, whether or not the magnetic head coil is selected correctly is detected by setting properly VH and VL properly. |
