In critical applications where failure of the 24V power supply is not tolerable, redundancy – where two or more supplies are paralleled – is the preferred fail-safe solution. In many conventional systems, diodes at the output of each supply ensure decoupling and isolation but suffer the problem of high inherent loss. At 20A load the loss per diode is around 10W in turn producing significant heat.
PULS has implemented a completely new technology in its YR-series of redundancy modules for load currents of 20-80A and input voltages from 12-60V where MOSFETs undertake the task of decoupling and significantly reduce this loss.
The figure below compares the losses in a conventional solution using decoupling diodes and PULS MOSFET technology. At a load current of 40A, losses are reduced to just 3W in the MOSFET module. Thus a compact DIN rail module only 36mm wide is possible. The user connects the outputs of the two power supply units to the inputs of the redundancy module and the safe supply voltage is available on the other side.
PULS MOSFET technology overcomes losses in output diodes
Additionally, when power supplies need to be operated in parallel, the load current must be distributed evenly over the individual power supplies to ensure thermal equilibrium and high reliability. PULS power supplies now have a selectable “parallel use” mode for this application to provide automatic current distribution between the units. With this feature current distribution is loss-free and therefore does not affect the redundancy concept.
The YR series is fully protected against short circuit or even reverse polarity, is covered by a portfolio of international standards, hot swapping capability and is housed in a compact and rugged housing to conserve space on the DIN rail.
About PULS
The PULS group is the world’s technological market leader in the field of industrial and DIN-rail power supplies, DC UPS, buffer modules and redundancy modules. The privately owned company headquartered in Munich is globally represented through its own subsidiaries and distribution partners. The units are developed in Germany and produced in Europe and Asia in its own environmentally friendly production plants.
