【正文】 ke the next level 1 transistor have larger current output, so must add positive bias, as shown in figure 9 (a) below. In order to reduce the transistor circuit impedance variations, base sibased ones to reduce as much as possible without light, when the reverse bias inherit in parallel a resistor sibased ones at both ends. Or like figure 9 (b) as shown by the positive ge diode produces pressure drop and test the voltage produced when exposed to light, make silicon tube e stack, b the voltage between actuators than V, and conduction work. This kind of circumstance also can use silicon light batteries, as shown in figure 10 (c) below. Semiconductor photoelectric element of photoelectric circuit can also use integrated operational amplifier. Silicon photosensitive diode can be obtained by integrating opamp larger output amplitude, as shown in figure 11 (a) below. When light is produced, the optical output voltage in order to guarantee photosensitive diode is reverse biased, in its positive to add a load voltage. Figure 11. (b) give the photocell transform circuit, because the photoelectric sibased ones shortcircuit current and illumination of a linear relationship between, so will it up in the opamp is, inversephase input, using these two potential difference between the characteristics of close to zero, can get better effect. In the picture shows conditions, the output voltage The photoelectric element by flux the role of different made from the principle of optical measurement and control system is varied, press the photoelectric element (optical measurement and control system) output nature, namely, can be divided into second analog photoelectric sensor and pulse (switch) photoelectric sensor. Analog photoelectric sensors will be converted into continuous variation of the measure, it is measured optical with a single value relations between analog photoelectric sensor. According to be measured (objects) method detection of target can be divided into transmission (absorption) type, diffuse type, shading type (beam resistance gears) three categories. Socalled transmission style means the object to be tested in optical path in constant light source, the light energy through things, part of being measured by absorption, transmitted light onto photoelectric element, such as measured liquid, gas transparency and photoelectric BiSeJi etc。s photoelectron effect, photon is moving particles, each photon energy for hv (v for light frequency, h for Planck39。s constant, h = * 1034 J/HZ), thus different frequency of photons have different energy, light, the higher the frequency, the photon energy is bigger. Assuming all the energy photons to photons, electronic energy will increase, increased energy part of the fetter, positive ions used to overe another part of converted into electronic energy. According to the law of conservation of energy: Type, m for electronic quality, v for electronic escaping the velocity, A microelectronics the work done. From the type that will make the optoelectronic cathode surface escape the necessary conditions are h A. Due to the different materials have different escaping, so reactive to each kind of cathode materials, incident light has a certain frequency is restricted, when the frequency of incident light under this frequency limit, no matter how the light intensity, won39。 The socalled diffuse style means the constant light by the light onto the analyte from the object to be tested, and projected onto surfaces reflect on after optoelectronic devices, such as photoelectric colorimetric thermometer and light gauge etc。m the idea of photoelectric sensor With the development of science and technology people on measuring accuracy had the higher request, this has prompted the pace with The Times photoelectric sensor have updated, improve the main means photoelectric sensor performance is the application of new materials, new technology manufacturing performance is more superior photoelectric element. For example, today the prototype of the photoelectric sensor is a small metal cylindrical equipment, with a calibration lens, transmitter into receiver focused light, the receiver out of cable to the device got a vacuum tube amplifiers in metal cylinder on the incandescent light bulb inside a small as the light source a strong incandescent lamp sensor. Due to the sensor various defects existing in the fields, gradually faded. To appear, because of it of fiber of excellent performance, then appeared with sensors supporting the use of optical passive ponents, another fiber without any interference of electromagnetic signal, and can make the sensor of the electronic ponents and other electrical disturbance in isolation. Have a piece of plastic optical fiber core or glass light core, light outside a metallic core skins and bread this layer metal cortical density lower than light core, so low, the beam refraction in the two materials according to the border (incident Angle within a certain range, reflected), is all. Based on optical principle, all beams can be made by optical fiber to transmission. Two incident beam Angle in an Angle (along the fiber length direction within) by multiple reflections from the other end after injection, another incident angles than accept the incident light in metal skin, loss. This accept Angle within the biggest incident Angle than two times, this is because fiber slightly larger from air into density larger fiber materials hitting may have a slight refraction. In light of the optical fiber transmission from inside the influence of fiber bending (whether more than bending radius minimal bending radius). Most optical fiber is flexible, easy to install in the narrow space. Photoelectric sensor is a kind of noncontact measurement small electronic measurement equipment, rely on detect its receives the light intensity change, to achieve measurement purposes, and it39。這種傳感器具有結(jié)構(gòu)簡(jiǎn)單、非接觸、高可靠性、高精度、可測(cè)參數(shù)多、反應(yīng)快以及結(jié)構(gòu)簡(jiǎn)單,形式靈活多樣等優(yōu)