【正文】 itch, S2 switch method for the speed selection key。機械式轉速表在測量轉速時，必須將轉軸接觸被測物體，以獲得同步轉速，通過內(nèi)部齒輪變速后用表頭指針指示轉速大小。轉速脈沖信號送入 8032 單片機的定時 /計數(shù)器，經(jīng)過單片機的軟件處理計算出轉速。本系統(tǒng) T2 用于定時，即計取定時脈沖信號，定時脈沖信號直接從 8032 芯片的地址鎖存信號端 ALE 引出，并經(jīng)過 74LS74 雙 D觸發(fā)器兩分頻后獲得。 S3為轉速 /頻率選擇開關，用來選擇測轉速還是測頻率。在中斷程序中， 8032 的 端輸出停止脈沖信號，置位觸發(fā)器 DFF2， Q2 端輸出低電平，封鎖門 4， T0、 T1同時停止計數(shù)?？梢姴捎?8032 中的 T2 計數(shù)器定時是本系統(tǒng)一個特點，它能顯著提高測速精度。 /頻率選擇開關 S3，當 ，表示 測頻率。 在定時法測速時，當不進行 n=60m1/p 的運算，直接將 1 s 內(nèi)的轉速脈沖數(shù)m1 變換為 BCD 碼顯示，所得的數(shù)值顯然就是輸入脈沖信號的頻率。而如果采用沒有重載功能的定時器如 T0 或 T1，則當定時器溢出時，須在響應中斷后，在中斷程序中重置定時器初值。當接受到轉速脈沖信號 fp 的上升沿時，觸發(fā)器 DFF1 翻轉， Q1為低電平，封鎖門 1，Q1為高電平，打開門 4，從而使 T2 開始定時， m1， m2 同時開始計數(shù)。 、 接 S1 和 S4開關， S1為極數(shù) P設定選擇開關， S4為極數(shù)輸入脈沖鍵。 2 轉速測量儀的硬件結構 圖 2 為由 8032 單片機構成的轉速測量儀電路圖。 光電轉換原理見圖 1。文中詳細介紹了該儀表的工作原理，給出了它的硬件原理圖和軟件流程圖。 singlechip microputer The rotor speed control system of industry is one of the important parameters. Mechanical tachometer measuring speed, the rotor contact with the measured object must be to get the synchronous speed, through the internal gear shift instruction after the pointer speed with the size of the header. Use of mechanical tachometer measured object can interfere with movement, especially when measured rotor mass is very small, speed tables on the rotor pressure is not a small additional load, which affects the measurement accuracy. This paper describes a 8032 singlechip microputer as the core to the noncontact Digital Tachometer. 1 speed measuring principle The gun speedsensitive devices with infrared sensors, launched by the specialized infrared detection devices, while receiving reflected back from the measured object infrared, photoelectric conversion into electrical pulses through the signal, does not affect the rotation of the object. Tubes and pipes are fixed in the detection of acceptable shelf, through the lens focus, semitransparent film not only to the reflected infrared light fired rotating objects, they can rotate the object by the reflected infrared light through the translucent membrane back fired for management. Along the circumference of a rotating body even paste some reflection paper, it directed reflection infrared to receive the reflected acceptance of the infrared control. Photovoltaic conversion shown in Figure In the optical triode 3DU5C adding an appropriate bias, when 3DU5C by infrared irradiation, at the conduction state, A point for the low level, 3DG6 end, B point is high。 select the use of M / T method speed, or velocity measurement with time. S3 for the speed frequency select switch, to select the measuring speed or frequency measurements. When using regular method to measure the speed, the system can be easily measured by measuring the frequency. 3 software design and anti