Humidifier controller having automatic over-current correcting means

A controller for controlling the operaiton of a steam humidifier having an electrode boiler and a humidistat operable when actuated to actuate the electrode boiler, said controller comprising:

• first control means responsive to the electrode current drawn by the electrode boiler for automatically initiating a corrective cycle when the electrode current exceeds a predetermined thereshold indicative of an undesired over-current condition;
• counter means for counting successive intiations of said corrective cycle;
• second control means responsive to the count in said counter means for disabling operation of said electrode boiler when said count reaches a predetermined number;
• rest means responsive to actuation of the humidistat for resetting the count in said counter means to an initial count lower than said predetermined number in response to actuation of the humidistat and for resetting said second control means to enable operation of the electrode boiler;
• and
• third control means responsive to the electrode current for measuring the time required for the electrode current to decrease between an upper predetermined substantially constant current level and a lower predetermined substantially constant current level, and for providing a control effect when said time is less than a predetermined time period.

A controller for controlling the operation of an electronic stream humidifier system, including an electrode boiler, a plurality of electrodes in said electrode boiler, a humidistat, a source of alternating current, a power contactor for coupling the electrodes of the electrode boiler to the source of alternating current in response to actuation of the humidistat, a solenoid controlled drain fill valve for admitting water into the electrode boiler and a solenoid controlled valve for draing water from the electrode boiler, said controller comprising:

• current sensing means including a current transformer for providing a variable voltage indicative of the electrode current drawn by the electrodes of the electrode boiler;
• a voltage comparator for comparing said current indicative voltage aganist a predetermined reference voltage to generate a first control voltage when the electrode current exceeds a predetermined maximum electrode current;
• a timer rsponsive to generation of said first control voltage for developing a second control voltage of substantially constant finite duration upon each generation of said first control voltage;
• a drain valve solenoid driver coupled to said timer and operable to open the solenoid controlled drain valve upon development of said second control voltage to drain water from the boiler for a peirod of time substantially equal in duration to the duration of said second control voltage;
• a counter responsive to the generation of said first control voltage for counting successive occurrences of the electrode current exceeding said predetermined maximum electrode current;
• a power contactor driver coupled to the power contactor and responsive to he count in said counter for decoupling the boiler electrodes from the source of alternating current when said count reaches a dredetermined number;
• reset means responsive to actuation of the humidistat for resetting the count in said counter to an initial number lower than said predetermined count upon actuation of the humidistat such that said power contactor driver decouples the boiler electrodes from the source of alternating current when the count in said counter reaches said predetermined number between successive actuations of the humidistat;
• and
• means responsive to the electrode current for measuring the time required for said electrode current to decrease between an upper predetermined substantially constant current level and a lower predetermined substantially constant current level, and for providing a control effect when said time is less than a predetermined time period.