JPH033014U

JPH033014U -

Info

Publication number: JPH033014U
Application number: JP1989063636U
Authority: JP
Priority date: 1989-05-31
Filing date: 1989-05-31
Publication date: 1991-01-14

Description

[Brief explanation of drawings]

第１図は回転速度低下検出回路の一実施例の説
明図、第１図ａは回路図、第１図ｂは回転速度が
正常な場合の回路図中の各点の波形を示す波形図
、第１図ｃは回転速度が低下した場合の各点の波
形を示す波形図、第２図は、回転速度上昇検出回
路の一実施例の説明図、第２図ａは回路図、第２
図ｂは回転速度が正常な場合の回路図中の各点の
波形を示す波形図、第２図ｃは回転速度が上昇し
た場合の各点の波形を示す波形図、第３図は回転
速度低下・上昇検出回路、第４図は回転速度変化
検出回路の出力信号の利用例の説明図、第４図ａ
は回転速度変化検出時に装置全体の電源を遮断す
る回路図、第４図ｂは回転速度変化検出時に警報
音を鳴らす回路図、第５図ａは従来の換気用フア
ンを示す斜視図、第５図ｂは従来の他の換気用フ
アンを示す斜視図、第５図ｃは回転速度パルスを
示す波形図である。１１，２１……基準パルス発生回路（単安定マ
ルチバイブレータ）、１２……ＡＮＤゲート回路
、１３，２３，３３，４３……パルス幅比較回路
（ＲＳフリツプフロツプ）、１４，２４，３４…
…リセツト回路、２２……ＮＯＲゲート回路、３
５……ＯＲゲート回路、４６……プラグ、４７…
…電源回路、４８……リレー、４９……ブザー、
Ｒ１，Ｒ２……抵抗、Ｃ１，Ｃ２……コンデンサ
。 FIG. 1 is an explanatory diagram of one embodiment of the rotational speed drop detection circuit, FIG. 1a is a circuit diagram, and FIG. 1b is a waveform diagram showing waveforms at each point in the circuit diagram when the rotational speed is normal. Fig. 1c is a waveform diagram showing the waveform at each point when the rotational speed decreases, Fig. 2 is an explanatory diagram of an embodiment of the rotational speed increase detection circuit, Fig. 2a is a circuit diagram, and Fig. 2a is a circuit diagram.
Figure b is a waveform diagram showing the waveform at each point in the circuit diagram when the rotation speed is normal, Figure 2 c is a waveform diagram showing the waveform at each point when the rotation speed increases, and Figure 3 is a waveform diagram showing the waveform at each point in the circuit diagram when the rotation speed is increased. Decrease/increase detection circuit, Fig. 4 is an explanatory diagram of an example of the use of the output signal of the rotational speed change detection circuit, Fig. 4a
4 is a circuit diagram that cuts off the power to the entire device when a change in rotational speed is detected, FIG. 4b is a circuit diagram that sounds an alarm when a change in rotational speed is detected, and FIG. FIG. 5b is a perspective view of another conventional ventilation fan, and FIG. 5c is a waveform diagram showing rotational speed pulses. 11, 21... Reference pulse generation circuit (monostable multivibrator), 12... AND gate circuit, 13, 23, 33, 43... Pulse width comparison circuit (RS flip-flop), 14, 24, 34...
...Reset circuit, 22...NOR gate circuit, 3
5...OR gate circuit, 46...Plug, 47...
...power supply circuit, 48...relay, 49...buzzer,
R1, R2...Resistor, C1, C2...Capacitor.

Claims

[Scope of utility model registration request]

Rotation detection means for detecting rotation of a ventilation fan and outputting a first pulse having a width corresponding to the rotation of the ventilation fan; and outputting a second pulse according to the width of the first pulse. and a pulse width comparison circuit that outputs a signal according to the result of comparing the width of the second pulse with a predetermined pulse width set in advance. .