powered by va 2r 2 u00d7 r watts or va 2 4r watts this method establishes a 4 to 1 power ratio between selected and unselected nibs a ratio that might be insufficient for high contrast printing referring to fig2 if phase b is maintained at some other voltage e g vx while phase a is powered by va the power distribution can be altered the selected nibs in all nib sets i viii of phase a continue to be powered by va 2 r watts the phase b nibs associated with selected phase a nibs will be powered by vx 2 r watts the remaining unselected nibs in both phases will be powered by va vx 2r 2 u00d7 r or va vx 2 4r watts thus vx can be used to lower the power dissipation in the unselected nibs at the expense of increasing the power dissipation in the phase b nibs associated with selected phase a nibs the preferred overall power ratio is obtained when the two spurious responses are equal that is when vx 2 r vavx 2 4r or vx va 3 the use of vx va 3 results in each unselected nib being powered by va.