摘要 |
<p>In one aspect, a handheld electric appliance includes: an oscillating electric motor or linear motor controlled by control circuitry; a battery connected to the oscillating electric or linear motor; and charge detection circuitry configured to determine a charging state of the battery. The charge detection circuitry is coupled to the control circuitry such that, in response to the charge detection circuitry determining that the charging state of the battery reaches a predetermined threshold, the control circuitry activates the oscillating electric motor or linear motor to cause noise generated by the motor to perceptibly change to indicate a threshold charging state.</p> |