| 摘要 |
PROBLEM TO BE SOLVED: To provide an inductive load drive circuit that can completely compensate the induced counter electromotive force produced when the circuit starts or terminates the drive of an inductive load or does not radiate at least the noise caused by the induced counter electromotive force to the outside. SOLUTION: Connecting terminals T1 and T2 for inductive load ZL upon which a positive induced counter electromotive force is impressed are connected to the negative electrode of a power source E through PNP transistors Q3 and Q4. Connecting terminals T2 and T1 upon which a negative induced counter electromotive force is impressed are connected to the positive electrode of the power source E through NPN transistors Q1 and Q2. Under this condition, a voltage having the same magnitude as the induced counter electromotive force has and a polarity opposite to that of the force is supplied to the connecting terminals T1 and T2 from the power source E. Since these actions occur in a moment, the voltages at the terminals T1 and T2 do not change and the induced counter electromotive force produced when the drive of the inductive load is started or terminated is compensated completely.
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