The invention discloses an electrical device for opening and closing a door or window, which consists of an
electrical mechanism and a
control circuit, and is characterized in that: the
electrical mechanism mainly comprises a motor, an
electromagnetic clutch, a counterweight, a transmission wheel and a
transmission belt, wherein the transmission wheel is mounted at a corner part of the upper partof a door or window frame, the
transmission belt goes around the transmission wheel and forms antiskid transmission fit, one end of the
transmission belt is connected with a door or
window opening and closing driving point, the other end of the transmission belt is connected with the counterweight, the motor is in transmission connection with the transmission input end of the
electromagnetic clutch, and the transmission output end of the
electromagnetic clutch is in transmission connection with the transmission wheel; and the
control circuit comprises an electromagnetic
clutch coil and a motor coil, wherein the electromagnetic
clutch coil forms a first power supply circuit relative to a power supply, and the motor coil forms a second power supply circuit relative to the power supply. The device shifts between an electrical mode and a manual mode automatically as the working state of the switch or remote controller changes without interfering with the switch or remote controller mutually, thereby bringing a great convenience to a user.