
48 Electric Motors and Drives
the collector of the transistor is only 0.7 volts above the
battery voltage. This 'clamping' action therefore limits the
voltage across the transistor to a safe value, and allows
inductive loads to be switched without damage to the switch-
ing element.
Features of power electronic converters
We can draw some important conclusions which are valid
for all power electronic converters from this simple
example. Firstly, efficient control of voltage (and hence
power) is only feasible if a switching strategy is adopted. The
load is alternately connected and disconnected from the
supply by means of an electronic switch