Patent attributes
A height adjustable desk includes a worksurface, a first leg and a second leg connected to the worksurface. The first leg is provided with a first motor to drive a first lifting apparatus for telescoping the first leg, while the second leg is provided with a second motor to drive a second lifting apparatus for telescoping the second leg. Each of the first motor and the second motor is provided with a magnetic device and two sensors. The magnetic device has several N-pole sections and S-pole sections, and the sensor detect a change of a magnetic field when the motor is turning. A control unit receives the signals of the sensor, and changes a speed of at least one of the motors until the signals are synchronous again when the control unit found that the signals are not synchronous.