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Power inverters

When designed as isolating converters, DC/DC converters can be used to invert voltage - that is, turn a positive input voltage into a negative output voltage. Connecting the input pin to the pin on the output side with the opposite pole turns a DC/DC converter into a power inverter. Since the transformer used in the DC/DC converter ensures complete electrical isolation between the input and output side, this will place the ground potential on the input side onto the positive terminal on the output side, giving the negative pole on the output side negative potential against ground. This means that the DC/DC converter acts as a polarity or power inverter. It is possible to connect one pin on the input side to one pin on the output side in all isolated RECOM converters; all ECONOLINE, POWERLINE and isolated INNOLINE converters can be used as power inverters.

A typical example of where these power inverters are used is where a negative reference voltage is needed - for example, in dual-slope A/D converters. Otherwise, two single-output DC/DC converters can be connected with one producing a positive voltage and the other - acting as a power inverter - producing a negative voltage. The easiest way of achieving this is to place ground potential onto the connecting point of the two converters, with the negative output of the second converter against the positive pole connected to ground yielding a negative voltage. Connecting -Vin to +Vout in the power inverter circuit layout described above is no longer necessary, since ground potential is only defined on the output side of the DC/DC converter and power inverter, independently of each module's input side. Power inverters not only help alter the level of input voltage on the output side, they can also reverse the polarity when correspondingly connected.