Patent ID: 8096445

Claim:
A battery-powered electric hand soap dispenser comprising: a housing; at least one battery supported by the housing; a reservoir configured to store liquid soap, the reservoir having an outlet, the reservoir being supported by the housing; a pump disposed in the housing, the pump having an inlet in fluid communication with the outlet of the reservoir; an electric motor supported by the housing for driving the pump, the electric motor being powered by the battery; a soap discharge nozzle in fluid communication with the pump with a soap conduit, the nozzle directed generally downwardly; a trigger sensor configured to detect the presence of an object, wherein the trigger sensor comprises a control routine configured to check whether a predetermined frequency of a plurality of reflected infrared light pulses has been received, and wherein the trigger sensor further comprises a light emitter device configured to emit the infrared light pulses at the predetermined frequency and a light receiver device, the trigger sensor being triggered when the light receiver device detects the plurality of the pulses of the reflected light at the predetermined frequency; an electronic control unit connected to the trigger sensor and to the electric motor, the electronic control unit configured to activate the light emitter device of the trigger sensor to generate the pulses of infrared light, the electronic control unit further configured to actuate the electric motor upon receiving a signal from the trigger sensor, until an amount of liquid soap has been ejected from the nozzle, the electronic control unit comprising: a light read module configured to read and store values corresponding to ambient light, the light read module comprising a routine that compares ambient light values to the reflected light pulses to diminish the risk of false triggers; a power supply sense module configured to sense a power Supply voltage and create a scaled motor drive time value; a fault detection module configured to stop operation of the motor and to provide an indication of a fault if the battery's power is below a predetermined level; wherein the electronic control unit is configured to dispense an amount of liquid soap only after a predetermined time period has elapsed from a previous ejection of liquid soap; and wherein the electronic control unit is configured to actuate the motor so as to drive the pump so as to dispense liquid soap in predetermined amounts.