The choice of optical relays is based on principles and methods. For beginners who are not too knowledgeable about this aspect, they cannot be chosen indiscriminately. The following article introduces this point of knowledge.
Three principles and methods for selecting a diaphragm relay
First of all, it must be carefully investigated and thoroughly understood about the nature of the controlled loop, the characteristics of the controlled loop, and the requirements for the diaphragm relay. Secondly, the various characteristics of the diaphragm relay itself, the use conditions, technical parameters, structural process characteristics and specifications and models, etc., to achieve a comprehensive grasp and careful analysis; from the advanced, rational, usable, economical comprehensive Consider making the correct choice and use of the iris relay. The principle of correctly selecting the diaphragm relay should be: (1) The main technical performance of the diaphragm relay, such as contact load, operating time parameters, mechanical and electrical life, etc., should meet the requirements of the whole system; (2) The structure type (including the installation method) and the external dimensions of the diaphragm relay should be suitable for the needs of the use conditions; (3) economical and reasonable.
As the first step in the selection of the diaphragm relay, it is to determine the classification of its application. Therefore, a type of diaphragm relay that has been successfully applied under given conditions is selected, and then the following steps are used to make the selected diaphragm relay the most. Suitable for specified applications. How to choose a diaphragm relay?
(1) Determine the type of diaphragm relay according to the input signal
A diaphragm relay of different action principle or structural characteristics requires that the nature of the input signal is different. For example, a thermo-optical relay is a diaphragm relay that operates by a thermal effect; an acousto-optic relay uses an acoustic effect; and an electromagnetic diaphragm relay activates and closes a contact by controlling an electromagnetic attraction generated by a current through a coil. This requires the user to first select the type of diaphragm relay according to the nature of the input signal. For example, when reacting voltage, current or power signals, select the voltage,
Current or power diaphragm relay; reactive pulse signal or polarity requirement
Pulse, polarized diaphragm relays, etc. should be used.
(2) Here, briefly introduce the difference between voltage and current diaphragm relays for the user to choose correctly. In terms of working principle, both of them belong to the electromagnetic diaphragm relay, and there is no difference. But from the design of the diaphragm relay, there is a difference between the two. The current diaphragm relay magnetic circuit system is considered according to IW=C, that is, when the inductance of the coil changes due to the action of the armature during the operation of the diaphragm relay, the loop current value is not affected. This current is determined by the large impedance of other circuit components in the loop, and the effect of the current diaphragm relay coil impedance on the overall loop impedance is negligible. Therefore, in general, the current aperture relay coil has a small number of turns, and the inductance and the resistance are small, so that the coil current is large. Supplying the current diaphragm relay coil is a constant current value. The signal input by the voltage stop relay coil is a relatively constant voltage value, typically the power supply voltage is applied directly to the coil or distributed to it via the network at a constant voltage value. Therefore, the loop current is mainly dependent on the coil impedance and generally does not involve other loop components. In order to minimize the shunting effect on other branches, the wire is generally thin, the number of turns is large, the inductance and resistance are large, and the coil current is not large.
(3) When selecting a current or voltage diaphragm relay, there must be relative circuit conditions. The current diaphragm relay requires a constant current source circuit condition, that is, the loop has a large impedance in series with it, and its own impedance has little influence on the loop current. Voltage stop relays require a constant voltage. The current diaphragm relay is used as a voltage diaphragm relay. Because of its small coil resistance, it is easy to burn the coil and even cause a short circuit in the power supply. If the voltage diaphragm relay is used in series with the current diaphragm relay, the large loop impedance will obviously change the original loop parameters, and the coil will not get enough current and the diaphragm relay will not operate.
It is worth noting that AC-iris relay coils typically have the ability to withstand overvoltages that are worse than DC-iris relays. In a DC diaphragm relay coil, the rate at which the current is increased due to an increase in the applied voltage is low. This is because the temperature rise of the coil causes the coil resistance to rise. However, in the AC diaphragm relay, an increase in the applied voltage causes an increase in the current, which also causes an increase in the coil resistance, which causes the magnetically permeable member to further saturate, so that the inductance is further reduced. As a result, the rate of increase of the coil current is faster than the rate at which the applied voltage is increased. Therefore, overheating due to the applied overvoltage is more likely to occur than the DC stop relay.
Plano-convex cylindrical lenses feature a single plano and single convex cylindrical surface, while their focal length is positive. These lenses operate only in one dimension rather than two, compared to plano-convex spherical lenses.
Plano convex cylindrical lenses are utilized to compress light in 1 axis. In order to generate a line image from a point of light and to change the aspect ratio of an image, a positive (convex) Cylindrical Lens is used. It is also applied to focus collimated input light to a line. Plano convex cylindrical lenses are normally used for line detector arrays, anamorphic beam shaping, laser projection, laser line focusing, and illumination of slit.
Plano Convex Cylindrical Lens,Meniscus Lens,Optic Lens,Cylinder Lens
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