| 摘要 |
PURPOSE:To obtain accurate constant current characteristics and to enable stable operation by eliminating the actual load current itself through a filter circuit by comparing it with a reference voltage. CONSTITUTION:There are provided a resistor Rf which generates a voltage Vs proportional to the current flowing through loads L1, L2, means (voltage comparator COP2, resistors R1-R3) for varying the voltage Vs to the feedback voltage Vf relative to the degree of the electromagnetic coupling between the loads L1 and L2, and means (TR1, TR2) for switching a load current in accordance with the compared result by the COP1 between the voltage Vf and the reference voltage Vi in a circuit for driving under constant current the loads L1, L2 electromagnetically coupled with one another by switching means TR1, TR2. Then, AVsu>Vsl, where a is the constant determined by the degree of the electromagetic coupling between the loads of 1>a>0, is satisfied between the maximum value Vsu and the minimum value Vsl of the voltage Vs. Accordingly, since the comparator COP1 alters from ON to OFF after it reaches the level of the comparator COP1, it can accurately control under constant voltage. |
