| 摘要 |
PURPOSE:To increase the switching speed of an output stage, and to improve servo response by using an FET as the output stage. CONSTITUTION:The drive circuit for the DC motor 21 is constituted by forming N type power FETS 22-25 in bridge shape, and each FET22-25 is driven by outputs from gate drive circuits 26-29. When the primary side currents of a photo coupler 30 are brought to an ON state in the gate drive circuit 26, a drive FET31 is turned ON and 32 is turned OFF, and the power FET22 is brought to an ON state. When the primary side currents of the photo coupler 30 are brought to an OFF state, the drive FET31 is turned OFF and 32 is turned ON, and the power FET22 is brought to an OFF state. The power FET22 is brought instantaneously to an OFF state because charges charged to the input capacity of the power FET22 pass through the drive FET32 and are discharged at that time. |
