JPH0488397U

JPH0488397U -

Info

Publication number: JPH0488397U
Application number: JP1990130469U
Authority: JP
Priority date: 1990-11-30
Filing date: 1990-11-30
Publication date: 1992-07-31

Description

[Brief explanation of the drawing]

第１図は本考案の実施例のブラシレスモータの
駆動回路を示す線図、第２図Ａ〜Ｂ３は本実施例
の通電回路内のＡ点〜Ｂ３点における電圧波形を
示す線図、第２図Ｃは本実施例の巻線Ｌ１の他端
のＣ点におけるサージ電圧発生時点での電圧波形
を示す線図、第２図Ｃ′は本実施例の巻線Ｌ１の
他端のＣ点におけるサージ電圧吸収後の電圧波形
を示す線図、第２図Ｄは本実施例のロータ位置検
出回路の出力端における電圧波形を示す線図、第
３図は本実施例の電界効果トランジスタのドレイ
ンにおける電圧波形を示す線図、第４図は従来の
ブラシレスモータの駆動回路を示す線図、第５図
Ａ〜Ｄは従来のブラシレスモータの駆動回路の通
電回路内のＡ〜Ｄ点における波形を示す線図、で
ある。ＩＣ１〜ＩＣ３……モノマルチバイブレイタ、
ＴＲ１〜ＴＲ９……トランジスタ、ＦＥＴ１〜Ｆ
ＥＴ３……電界効果トランジスタ、ＣＰ１〜ＣＰ
３……コンパレータ。 FIG. 1 is a diagram showing a drive circuit of a brushless motor according to an embodiment of the present invention, FIGS. Figure C is a diagram showing the voltage waveform at point C at the other end of the winding L1 of this embodiment at the time of occurrence of the surge voltage, and Figure 2 C' is a diagram showing the voltage waveform at point C at the other end of the winding L1 of this embodiment. A diagram showing the voltage waveform after absorbing the surge voltage, FIG. 2D is a diagram showing the voltage waveform at the output end of the rotor position detection circuit of this embodiment, and FIG. A line diagram showing voltage waveforms, Fig. 4 is a line diagram showing a conventional brushless motor drive circuit, and Figs. 5 A to D show waveforms at points A to D in the energization circuit of the conventional brushless motor drive circuit. It is a line diagram. IC1~IC3...Mono multivibrator,
TR1~TR9...transistor, FET1~F
ET3...field effect transistor, CP1~CP
3... Comparator.

Claims

[Claims for Utility Model Registration] A rotor having a magnet around a shaft and rotatably arranged around the shaft, and a plurality of windings arranged around the rotor and having one end connected to a power source. A drive circuit for a brushless motor, comprising: a rotor position detection means for detecting the position of the rotor from a voltage induced in the winding by the rotor; control means for outputting a control signal for sequentially exciting each of the windings based on the position of the rotor; a first switching means that turns on and off the windings when the windings are on, and cuts off the electricity to the windings when the windings are turned off; a second switching means for turning on the first switching means by a voltage induced in each of the windings;
A brushless motor drive circuit equipped with switching means and.