MTM Power, the specialist for individual power supplies, has released primary switched DC/DC converters with 400W output power especially designed for automotive applications. They operate according to the push-pull principle; i.e. the input DC-voltage is chopped by two push-pull working transistors with a frequency of approximately 60kHz. With the help of a transformer and a secondary linear choke, a galvanically isolated output voltage (12V or 24V) is produced, which is adjusted by pulse-width modulation according to the current mode principle.
The series PCMD400W is available with input voltages of 36VDC, 72 VDC, 80VDC and 110VDC and can be connected via screw connectors. The dimensions of the devices, which are available in an aluminium case, are 150mm (length) x 86mm (width) x 55mm (height). Due to this compact design, they are also suitable for applications where only a little space is available.
The converters need no ground load, are maintenance free, and are short-circuit protected by primary and secondary power limitation. They are vacuum potted, prepared for use in devices with Protection Class II and fulfil the low voltage directive. They can be optionally constructed for use in railway applications. Further features are a mechanically and electrically rugged design using SMD-technology and an automatic piece-by-piece test. To ensure a smooth operation, it is necessary to mount the converters on a heat-dissipating surface.