Portable electric tool

A portable electric tool comprising:

• a. a handle;
• b. casing for a motor;
• c. a non-drive end cover having a bearing at its center for the said motor;
• d. a heat sink provided either integrally, or separately on the covers;
• e. a PWM bridge inverter consisting of power transistors with corresponding;
• gates, the output of the said PWM bridge inverter is connected to said motor;
• f. power transistors connected to a printed circuit board (PB) and mounted on said heat sink;
• g. a controller unit having a software program of short code length and a driver IC for driving said gates are further connected to a printed circuit board (CB) for driving said gates;
• h. two printed circuit boards (PB & CB), that are inter-connected for determining timing sequences for generating signals for switching ON/OFF said gates of said power transistors of said PWM bridge inverter in order to produce variable voltage variable frequency, sinusoidal wave forms for controlling the speed of the motor by using space vector pulse width modulation or sinusoidal pulse width modulation technique, and said printed circuit boards are mounted through mounting means to the heat sink;
• i. a cooling means mounted on a shaft of the motor to first cool the PB & CB printed circuit boards that are mounted on said heat sink and thereafter cool said motor;
• and
• j. an input rectifier and filter capacitors connected to said PWM bridge inverter, and an auxiliary power supply, which provides the power supply to said controller unit and said driver IC which are housed in said handle of said portable tool.