| 摘要 |
PURPOSE:To lower a power level in a circuit and to facilitate the integration of the circuit, by connecting one constant-current circuit serially to a bridge consisting of four constant-current circuits. CONSTITUTION:Resistors in each component of a bridge of a magnetization compensating circuit of a magnetic head 1 are replaced by constant-current circuits 15-18, and one constant-current circuit 20 is connected to one input terminal of the bridge. Two constant-current circuits 16 and 18 connected to a lower-side input terminal D are variable and constituted so that current values thereof vary differentially, while two contant-current circuits 15 and 17 connected to an upper-side input terminal C are set to make equal current I flow respectively. Accordingly, the circuit current totals 2I. So as to obtain the maximum value DELTAIBm of a bias current flowing through the signal winding 3 of the magnetic head 1, it suffices that I is made to be equal to DELTAIBm and thus the bridge can be made effective with the circuit current twice as large as the maximum value of a required bias current. By this constitution, the power level of the circuit can be lowered and the integration of the circuit is facilitated. |
