| 摘要 |
PURPOSE:To reduce noise of the power source by making the energized current waveform of a DC motor correspond to the waveform of the voltage by half-wave or full-wave rectification of an AC power source voltage. CONSTITUTION:Current flowing through a DC motor 5 is detected with a resistance 6. As the output detected rises beyond the upper slice level of a Schmitt trigger circuit 13, it shuts off transistors 14 and 3. This reduces the armature current. As the output voltage of the resistance 6 falls below the lower slice level of the Schmitt trigger circuit 13 with an decrease in the armature current, the transistors 14 and 3 conduct causing the armature current to increase again. An energized current value of the DC motor 5 can be altered with a variable resistance 8. This can reduce noise of the power source to check the generation of noise, vibration or the like. |
