Controller for commutator motor for electric hand tools , divides direct voltage into first and second ranges with fixed sectional height in second range during operation of motor without changeover processes

摘要

The controller has first and second control devices (4,5) associated with a pulse width modulator (3) for first and second frequency sections of a direct voltage. The direct voltage is divided into first and second sections with a fixed D.C. level in the second sections during the operation of the motor (1) without changeover processes and for a smooth transition from steady to increasing rotary characteristic.