Patent ID: 7455245

Claim:
A diffusion device, comprising: a housing having a battery disposed therein and adapted to receive a replaceable fluid reservoir for holding a fluid, the fluid reservoir including a wick for movement of the fluid to a discharge end thereof; a piezoelectric element energized by the battery for vibrating a perforated orifice plate disposed adjacent the discharge end of the wick, wherein the piezoelectric element develops vibratory movement to pump the fluid from the discharge end through the perforated discharge plate and into the atmosphere; and a control circuit and a light emitting diode (“LED”) disposed in the housing, wherein the control circuit rapidly switches the LED between on and off states in response to the operation of a switch that alternately connects and disconnects a current source to the LED when the piezoelectric element is energized and a voltage developed by the control circuit is above 3.0 volts such that the battery is prevented from cycling in and out of a low battery condition.