exceeding a predetermined threshhold q13 is switched off while q1 remains on the current path for u03c6 1 now becomes throiugh the collector emitter of q1 via winding 102 and diode d5 back to source v 1 hence u03c6 1 current will decay slowly because both sides 151 and 152 of u03c6 1 winding 102 are at substantially equal potentials such slow current decay permits a relatively low chop frequency and results in reduced heat dissipation in q13 during chopping as compared to prior art chopping arrangements as an example of current switching or translation between stator phase windings assume u03c6 1 current is flowing and we wish to switch stator winding current to u03c6 2 winding 103 to translate the enable signal is removed from path 111 and a new enabling logic one signal is applied to path 112 by translator 110 fig1 as q1 is switched off the current path for u03c6 1 winding 102 to the negative voltage supply v 2 via diode d7 causes u03c6 1 current to decay rapidly allowing fast commutation to phase u03c6 2 diode d2 in functional block 202 corresponding to diode d1 of block 201 serves to protect phase enabling transistor q2 of block 202 from.