# Total current used by a brushless DC motor

Is it correct to say that 'the current' drawn by a BLDC motor is the same as the current from any single phase at a given time (assuming they are all balanced/equal in magnitude)?

I came across this diagram describing the characteristic shape of a BLDC current waveform:

From this diagram, it seems that the current is roughly flowing through one phase at a time, with only a tiny amount of overlap. What this doesn't look like is three sinusoidal waveforms 120° out of phase - a situation where the total current is more easily understood and calculated.

What is convention here?

• if you invert all the negative currents, and add up the three phases, you will see that the total current is a sawtooth waveform that alternates between the + value and 2x the + value – jsotola Feb 6 '18 at 18:21