US Patent 10317999 Vibrotactile driver circuit for haptic devices

A haptic device comprises a wearable material configured to a portion of a user. A vibrotactile actuator is coupled to the wearable material and provides haptic feedback in accordance with a drive signal. A driver circuit is electrically coupled to the vibrotactile actuator and provides the drive signal to the vibrotactile actuator. The driver circuit includes an alternating current (AC) voltage source assembly that has a first AC voltage source and a second AC voltage source, each having a terminal. The terminal of the first AC voltage source is electrically coupled to the vibrotactile actuator. A capacitive element electrically is coupled to the terminal of the negative AC voltage source and a regulating element. The regulating element includes a first coupling point and a second coupling point. The first coupling point is electrically coupled to the capacitive element and the vibrotactile actuator, and the second coupling point is grounded.