First the important factors of the terminal selection is the power handling device. Simply read the data sheet does not guarantee access to accurate comparative data. Engineers must understand the manuals listed in the product performance test data is how to determine the.

Currently, UL, IEC, CSA and DIN mechanism have no uniform standard in determining the terminal product power and performance specifications. Users need to understand the differences between UL and IEC specifications. On the making of Europe terminal product specifications using the IEC standard, while in the United States of America manufacturing products using the standard UL.

The two differences between standard is very large. Do not understand the product specification method for the determination of the engineer will take a considerable risk, because the device may not reach the required power level, or use the device specifications far beyond the design needs. In Europe, the device current rating is by monitoring the current increases when the metal conductor temperature to determine. When the metal pin temperature higher than ambient temperature above 45 DEG C, measuring staff will then current as the device of the rated current value ( or the maximum current value ). The IEC specification of another is to allow the current value, it is the maximum current of 80%. In contrast, UL standards will enable the metal conductor temperature higher than ambient temperature of 30 DEG C when the current value of 90% as the device's current nominal value. Thus, the metal conductor portion of the temperature in all applications are very important factors. It is more important for industrial equipment. Because industrial equipment usually requires high temperatures up to 80 degrees in the work environment. If the terminal temperature than the high temperature of 30 DEG C or 45 degrees C, the temperature on the terminals will be more than 100 DEG c.. According to the choice of devices using nominal value types and insulating materials, products must be lower than the rated value of the current work, so as to ensure that they can be at a desired temperature range and reliable work. Sometimes, suitable for compact packaging materials may not be well meet the requirement of heat dissipation, so this kind of terminal device using the current must be substantially lower than the rated value. So, how to choose the terminal reflects the importance of.

With the globalization, the need design is in a global sales system, so the system designers have become more and more frequent use of produced in other countries the power terminal product. Since the European nominal value measurement method, therefore the device in the design below the nominal value in use in Europe is common practice. However, many American designers are not familiar with this concept, if not understand the differences between standard, in the design process will be difficult.

In the choice of devices, often be overlooked is another factor to products used by the terminal technology. Most power terminal products are still in use through hole connections. This method may be needed to provide mechanical support, and can ensure that the multilayer circuit board with embedded in the power supply layer remains solid electrical contact. And to be used for terminal connected to the circuit board pin has a variety of different types of. Some companies provide only a single pin type, others provide multiple pin product. Multiple pin product advantages: it can make the current more evenly distributed to the circuit board wiring, provide more reliable mechanical stability and improve welding firmness.