Vibration actuator with a unidirectional drive

A method of generating a haptic effect comprising:

• generating a unidirectional signal;
• applying the unidirectional signal to a linear resonant actuator;
• and
• based on the unidirectional signal, generating a vibration at the actuator;
• wherein said linear resonant actuator comprises a spring, a magnetic coil and a floater assembly;
• wherein the unidirectional signal is a sinusoidal signal with an amplitude that varies between a first voltage greater than or equal to zero and a second voltage greater than or equal to zero;
• wherein the unidirectional signal, when applied to the actuator, causes the magnetic coil to be energized and the floater assembly to move, wherein the movement of the floater assembly generates the vibration.

A portable device comprising:

• a linear resonant actuator;
• a drive circuit coupled to said linear resonant actuator, said drive circuit adapted to output a unidirectional signal;
• and
• a processor coupled to said linear resonant actuator;
• wherein said linear resonant actuator comprises a spring, a magnetic coil and a floater assembly;
• wherein the unidirectional signal is a sinusoidal signal with an amplitude that varies between a first voltage greater than or equal to zero and a second voltage greater than or equal to zero;
• wherein the unidirectional signal, when applied to the actuator, causes the magnetic coil to be energized and the floater assembly to move, wherein the movement of the floater assembly generates a haptic force.