For this purpose, the current adding transformers offer an easy solution. These devices have several input windings In/5 and an output winding which gives a value proportional to the sum of the input currents with a full of 5 A (see fig. 2).
The output current of the adder transformer is obtained by means of the following expression:
where n is the input number of the transformer and I1, I2, ..., In are the current of each input. The addition is only possible when the input currents come from transformers having the same current ratio. Current adders for different ratio inputs can be supplied on request.
Fig 3.
Fig 2.
