After the set start time (tStart) has timed out, the thyristors are
fully controlled (full sinusoidal half wave => Top Of Ramp: TOR).
As the thyristors are only active during the acceleration phase
or during the deceleration phase, they can be bypassed by socalled
bypass contacts during continuous operation. The losses
on the soft starter can be reduced by the considerably lower
contact resistance of the mechanical switching contacts.
On soft starters, a differentiation is made today between two
principle variants in the configuration of the power sections (figure
8).