The present invention relates to a portable adhesive dispensing appliance with
adjustable duty cycle. Rather than applying power continuously to the heating element,
the element power is intermittently switched over to a variable duty cycle. Savings
are gained in three areas: extended life of the element; less heat lost to thermal
radiation; and less adhesive waste due to dripping and overheating. The duty cycle
may be adjusted manually or automatically based on the temperature of the adhesive
in the melt chamber. Additionally, the voltage and/or current to the heating element
may be adjusted, either manually or automatically, for more rapid recovery during
high usage periods. Higher throughput is achieved by sensing the temperature, comparing
the temperature to a desired temperature, and then increasing the duty cycle by
either or both one of increasing the frequency of duty pulses and/or lengthening
the duration of the duty pulses.
