JPH0454499U

JPH0454499U -

Info

Publication number: JPH0454499U
Application number: JP1990095244U
Authority: JP
Priority date: 1990-09-11
Filing date: 1990-09-11
Publication date: 1992-05-11

Description

[Brief explanation of the drawing]

第１図は本考案に係るブラシレスモータの回転
数検出装置の一例の構成図、第２図は同各部波形
、第３図は従来のブラシレスモータの回転数検出
装置の一例の構成図、第４図は同各部波形である
。１……ブラシレスモータの回転数検出装置、２
……逆起電圧波形整形回路、３……位置信号波形
整形回路、３ａ……シユミツトトリガ回路、４…
…演算回路、４ｂ……Ｄフリツプフロツプ回路。 FIG. 1 is a configuration diagram of an example of a rotation speed detection device for a brushless motor according to the present invention, FIG. 2 is a waveform of each part of the same, FIG. 3 is a configuration diagram of an example of a conventional rotation speed detection device for a brushless motor, The figure shows the waveforms of the same parts. 1...Brushless motor rotation speed detection device, 2
... Back electromotive voltage waveform shaping circuit, 3... Position signal waveform shaping circuit, 3a... Schmitt trigger circuit, 4...
...Arithmetic circuit, 4b...D flip-flop circuit.

Claims

[Scope of utility model registration request]

A multi-polar magnetized rotor and this
The rotational speed of a brushless motor, which is composed of a plurality of drive coils and a plurality of position detection elements provided facing a magnetic rotor, and detects the rotational speed based on the alternating frequency of a back electromotive force generated in the drive coil. In the detection device, the rotation speed detection device includes a back electromotive voltage waveform shaping circuit that shapes the waveform of the back electromotive voltage, and a rise of the back electromotive voltage component from the rise of the noise component of the output of the back electromotive voltage waveform shaping circuit. a position signal waveform shaping circuit that shapes the waveform of the position signal using a threshold value set so that the position signal detected by the position detection element falls and then rises after a certain period of time; Outputting a signal of the same high or low level as the output signal of the position signal waveform shaping circuit at the rise or fall of the output signal of the shaping circuit, and when the output signal of the position signal waveform shaping circuit becomes high level; A rotation speed detection device for a brushless motor, characterized in that it is equipped with an arithmetic circuit that outputs a high-level signal unconditionally.