A processing, power factor

First of all, one of the factors to consider is the power handling capability of the device.Simply read the data sheet does not guarantee access to accurate comparative data.Engineers must understand the product performance data of the listed in the manualtest is how to determine the. At present, UL, IEC, CSA and DIN and other institutions indetermining the power and performance specifications of the terminal product and there is no uniform standard. Users need to understand the difference between UL and IEC specifications. Using the IEC standard in the making of Europe terminal productspecifications, and in USA manufacturing products using the standard UL. There are wide variations between the two criteria. Do not understand the determination method ofproduct specifications, engineers will take a considerable risk, because the selecteddevice may not reach the power level required, or use the device specifications far beyond the design needs. In Europe, the current rating devices by monitoring the current value is increased when the metal conductor temperature to be determined.When the metal pin temperature 45 C higher than the temperature of the environment,measuring staff will then current as the rated current of the device (or the value of the maximum current value). Another of the IEC specification is to allow the current value, it is the maximum current of 80%. In contrast, UL standard will make the metal conductor temperature of 30 C higher than the temperature of the environment when the currentvalue of 90% as the current value of the nominal device. Thus, the metal conductorportion of the temperature is a very important factor in all applications. This is more important for industrial equipment. Because industrial equipment often need to work in the environment of high temperature of 80 DEG C in. If the terminal temperature higher than the temperature of 30 DEG C or 45 DEG C, then the temperature will exceed 100degrees C terminal. According to the nominal value types and the insulating material is selected by the devices, products must be lower than the current work of the rated value, so as to ensure that they can be at the desired temperature ranges work reliably.Sometimes, suitable for compact package device materials may not be good to meet thecooling requirements, so the current such terminal device when in use must besubstantially lower than the rated value.

In the choice of devices, another factor is often ignored is the use of the products of thetermination technique. Most of the power connecting terminal products are still in useconnection through hole. This method can provide the required mechanical support,and can guarantee the power supply and embedded in the multi-layer circuit boardlayer to keep solid electrical contact. But to the wiring terminals are connected to the circuit board of the pin has a variety of different types of. Some companies only provide single pin type, others provide multi pin products. In the multi pin product advantages: itcan make the current distribution to the circuit board more evenly to walk the line,provide mechanical stability more reliable and improve the firmness of welding.

Two, appearance factors

Although "the sound of the name of a power supply terminal" is not beautiful, but manycompanies consider it and aspects of the affinity of the user in the appearance of the product have played an important role in. Power supply terminal must be convenientfield installation, because they are often installed in the front panel is easy to see theproduct. Thus, marketers often wish to have a certain right to speak to the power supply terminal product appearance. But often encounter this situation: the engineer to designproducts to meet the requirements of all mechanical and electrical parameters, but not satisfied with sales requirements and have to change. Finally, if this happens in the design cycle (often is the marketing department first saw the prototype time), then a fierce argument would be difficult to avoid, and is likely to lead to rising costs and delay in delivery. In many industrial control system, terminal is often one of the technical staffneed to pay attention to several parts of the few. Although the user interface is relatively simple (mainly screw), but for the normal operation of the equipment is veryimportant.

In general, as the current increases, the wire becomes more coarse, but these coarsewire fastening required in terminals also need to increase the torque. Therefore, the power supply terminals need more and more solid insulating casing screw. Sometimes small screws will be used to save space. So often in the terminal product is verycompact in. Some wire diameter of 1/4 inch above, so the small screw is difficult to deal with. When the technical personnel and repair staff need to install multiple lines, usinglarge enough to simplify the connection screw work can greatly save time.