Patent ID: 7839112
Filing Date: 2010-11-23
Classification: H02P

Abstract:
1. A torque control circuit of impact tool characterized by comprising an electric motor driving circuit, an electric motor operating current detection circuit, a reference voltage generation circuit, a maximum electric motor current setting circuit, an electric motor impedance torque setting circuit, an information output circuit, a regulated-voltage power supply circuit, and a control circuit, wherein the regulated-voltage power supply circuit supplies power supply voltage and the control circuit comprises an integrated circuit to carry out functions of reading information detection sources, processing, and instruction for execution of torque control, output terminals of the reference voltage generation circuit, the maximum electric motor current setting circuit, and the electric motor impedance torque setting circuit being respectively connected to corresponding input terminals of the integrated circuit, the integrated circuit signaling and controlling the electric motor driving circuit and the reference voltage generation circuit respectively and outputting an instant electric motor torque value to the information output circuit, the electric motor driving circuit being connected to an electric motor and connected in serial to the electric motor operating current detection circuit, an input terminal of the maximum electric motor current setting circuit being connected to connection between the electric motor operating current detection circuit and electric motor driving circuit, an output terminal of the maximum electric motor current setting circuit other than that connected to the integrated circuit being connected to a gate control terminal of the electric motor driving circuit.