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EETE NOV 2014 High-Performance, high reliable Power Supplies 15 W to 12 kW+ adapted to your challenging projects l AC/DC Power Supplies l Rectifiers and Battery Chargers l DC/DC Converters l Sine-Wave Inverters l Phase and Frequency Converters l AC- Input, DC-output UPS systems l Open Frame l Wall mount l 19” Cassettes l DC-input dimmable back-light inverters for LCD displays l Complete Power Systems in 19" and 23" Racks ABSOPULSE Marketing Europe GmbH PoBox 1501 8620 Wetzikon CH Tel. +41 78 896 50 49 Fax +41 44 944 38 44 Write us: See us: Fig. 2: Thermal results using different Infineon IGBT families on the 4.5 kW welding machine demonstrator introduced. The stray inductance reduction enables systems to run at switching frequency exceeding 100 kHz, which implies the possibility to use a single heat sink to increase the power density and reduce the transformer size along with the number of DC-Link capacitors needed. Improvements in full bridge topology Another design example, a 3.5 kW Full-Bridge high frequency welding machine, is illustrated in Figure 4. Here, the purpose of the design is to showcase Trenchstop 5 in full bridge topology replacing conventional MOSFETs for lower cost, better manufacturability as well as higher reliability. Once again the low turn-off losses of the Trenchstop 5 IGBT technology are the key enabler of the system architecture improvements achieved thanks to the new design. This feature, along with the higher current carrying capability of IGBTs compared to MOSFETs, allows replacing three conventional HVMOSFETs with one single IGBT device. Due to a lower number of devices required, the power- and driving-stage can be easily integrated on a smaller board instead of having a driver board on top of a power board. Compared to this common approach, the total board area needed for the new approach is one third smaller than the former version. Moreover, the significant reduction of parasitic inductance in the power loop allows turning off the Trenchstop 5 at higher di/dt, still maintaining the voltage overshoot within the recommended specification. The demonstrator was developed to simplify the architecture, as well as to increase power density. With this hardware, it is possible to show how to reduce the effort for the assembly Fig. 3: Second 4.5 kW Half-Bridge welding machine demonstrator 32 Electronic Engineering Times Europe November 2014

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