JPH0416364U

JPH0416364U -

Info

Publication number: JPH0416364U
Application number: JP5790290U
Authority: JP
Priority date: 1990-05-30
Filing date: 1990-05-30
Publication date: 1992-02-10

Description

[Brief explanation of drawings]

第１図は本考案の第１実施例に係る車輪速検出
器の一部断面概略図、第２図は第１実施例の回路
部の回路図、第３図は感磁素子が出力するアナロ
グ信号を示す波形図、第４図はオフセツト除去回
路が出力するアナログ信号を示す波形図、第５図
はしきい値回路におけるアナログ信号のデジタル
信号への変換を示す波形図、第６図は本考案の第
２実施例を示す回路図、第７図は従来の感磁素子
を使用するタイプの車輪速検出器におけるアナロ
グ信号のデジタル信号への変換を示す波形図であ
る。１……車輪速検出器、２……ケース、３……セ
ンサロータ、４……感磁素子、５……磁石、６…
…回路部、１０……オフセツト除去回路、２０，
２０′……しきい値回路、Ｖｔｈ……しきい値電
圧。 Fig. 1 is a partial cross-sectional schematic diagram of a wheel speed detector according to the first embodiment of the present invention, Fig. 2 is a circuit diagram of the circuit section of the first embodiment, and Fig. 3 is an analog output from the magnetic sensing element. Figure 4 is a waveform diagram showing the analog signal output by the offset removal circuit. Figure 5 is a waveform diagram showing the conversion of the analog signal into a digital signal in the threshold circuit. A circuit diagram showing a second embodiment of the invention, and FIG. 7 is a waveform diagram showing conversion of an analog signal into a digital signal in a wheel speed detector of a type using a conventional magnetic sensing element. DESCRIPTION OF SYMBOLS 1...Wheel speed detector, 2...Case, 3...Sensor rotor, 4...Magnetic sensing element, 5...Magnet, 6...
...Circuit section, 10...Offset removal circuit, 20,
20'...Threshold circuit, Vth...Threshold voltage.

Claims

[Claims for Utility Model Registration] 1. A magnetic sensing element that magnetically detects the motion of the rotating body and outputs an analog signal, in a case disposed close to a rotating body to be detected that is interlocked with the wheels. ,
The wheel speed detector includes a circuit section having a threshold circuit for converting an analog signal from the magnetic sensing element into a digital signal, and an offset voltage of the analog signal output from the magnetic sensing element is installed in the circuit. A wheel speed detector characterized in that an offset removal circuit comprising a high-pass filter is provided to remove the offset and output it to the threshold circuit. 2. The circuit section including the threshold circuit and the offset removal circuit and the magnetically sensitive element are housed separately in the case, and the magnetically sensitive element is arranged on the front side of the case on the side facing the rotating body. 2. The wheel speed detector according to claim 1, wherein the circuit section is disposed at a rear part of the case behind the magnetic sensing element. 3 The high-pass filter of the offset removal circuit described above has a cutoff frequency of 0.1 km/h to 0.1 km/h.
3. The wheel speed detector according to claim 1, wherein the wheel speed detector is set to a frequency corresponding to a wheel speed of 5 km/h.