| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to drive a coil with a current without creating distortion to signal, by applying currents of an almost identical value in forward direction to a first and a second current passages of an output circuit. SOLUTION: Emitters of a PNP type transistor 51 and an NPN type transistor 52 are connected in an input portion of an output circuit 2, and diodes 54 and 55 are connected in series between the bases of both the transistors 51, 52. A current of a current source 56 is supplied to the diodes 54, 55, and a voltage of a voltage supply 53 is supplied to the base of the transistor 51. By doing this, a current equal to a current value of a current source 56 can be always applied from the collector of the transistor 52 to the collector of transistor 51. Also, by connecting the collector of the transistors 11, 14 to the collector of the transistor 41 in series, the frequency characteristics of the coil drive equipment can be adjusted and a current drive to the coil can be performed without distortion to signal. |
