Control circuits for hot melt adhesive heater circuits and applicator heads

An electronic control circuit for use in connection with hot melt adhesive dispensing equipment, comprising:

• an electrical power source;
• a relatively large applicator head which is effectively divided into a plurality of zones;
• a plurality of heater assemblies distributed throughout said relatively large applicator head such that one of said plurality of heater assemblies is disposed within each one of said plurality of zones defined within said relatively large applicator head, wherein each one of said plurality of heater assemblies is operatively associated with each one of said plurality of zones defined within said relatively large applicator head so as to heat the hot melt adhesive material, being fluidically conducted internally within each one of said plurality of zones defined within said relatively large applicator head, to a predetermined temperature level;
• a plurality of temperature sensors distributed throughout said relatively large applicator head such that one of said plurality of temperature sensors is disposed within each one of said plurality of zones defined within said relatively large applicator head, wherein each one of said plurality of temperature sensors is operatively associated with each one of said plurality of zones defined within said relatively large applicator head so as to effectively sense the temperature level of the hot melt adhesive material being fluidically conducted internally within each one of said plurality of zones of said relatively large applicator head, and to effectively control the energization of each one of said plurality of heater assemblies disposed within each one of said plurality of zones defined within said relatively large applicator head so as to maintain the temperature level of the hot melt adhesive material, being conducted internally within each one of said plurality of zones defined within said relatively large applicator head, at said predetermined temperature level;
• switching means for selectively electrically connecting each one of said plurality of heater assemblies, disposed within each one of said plurality of zones defined within said relatively large applicator head, to said electrical power source;
• and
• means for controlling said switching means, in response to temperature levels respectively sensed by said plurality of temperature sensors, so as to selectively electrically connect particular ones of said plurality of heater assemblies to said electrical power source in order to selectively maintain each one of said plurality of zones of said relatively large applicator head at said predetermined temperature level.