Millivolt damper control device

Abstract

A millivolt damper control device comprises a damper movable between a closed position where a flue is blocked and an open position, a thermoelectric device having an input voltage, a battery having a voltage, and a controller comprising a comparator circuit which compares the input voltage with a reference voltage based upon the voltage of the battery. When the input voltage is greater than or equal to the reference voltage, the comparator circuit transmits a damper signal to move the damper to the open position.

1 . A damper control device comprising, in combination: 
 a damper movable between a closed position and an open position;    a thermoelectric device;    a battery having a voltage; and    a controller comprising a comparator circuit which compares an input voltage from the thermoelectric device with a reference voltage based upon the voltage of the battery;    wherein when the input voltage is greater than or equal to the reference voltage, the comparator circuit transmits a damper signal to move the damper to the open position.    
   
   
       2 . The damper control device of  claim 1  further comprising 
 an electric motor having a rotatable shaft operatively connected to the damper which moves the damper between the open position and the closed position;    wherein the damper signal comprises application of the reference voltage across the motor.    
   
   
       3 . The damper control device of  claim 1  wherein the battery supplies electric power to a motor which moves the damper and to the comparator circuit.  
   
   
       4 . The damper control device of  claim 1  wherein the battery is mounted on a box which also houses the comparator circuit.  
   
   
       5 . The damper control device of  claim 1  wherein the comparator circuit applies a voltage to open a gas valve to initiate combustion when a fire is desired at a fireplace, and removes the voltage to close the gas valve and terminate combustion when a fire is no longer desired at the fireplace.  
   
   
       6 . The damper control device of  claim 5  wherein when the fire is desired at the fireplace, the comparator circuit opens the gas valve after receiving a damper status signal indicating that the damper is in the open position.  
   
   
       7 . The damper control device of  claim 1  wherein the comparator circuit maintains a predetermined time delay corresponding to a time between when the input voltage is removed from the comparator circuit and when the reference voltage is reapplied at the motor.  
   
   
       8 . A damper control device comprising, in combination: 
 a damper;    a motor which moves the damper between a closed position and an open position;    a thermoelectric device;    a battery having a voltage; and    a controller comprising a comparator circuit which compares an input voltage from the thermoelectric device with a reference voltage based upon the voltage of the battery;    wherein the comparator circuit maintains a predetermined time delay corresponding to a time between when the input voltage is removed from the comparator circuit and when the reference voltage is reapplied at the motor.    
   
   
       9 . The damper control device of  claim 8  wherein power to run the motor is supplied by the battery, and power to move the gas valve is supplied by the thermoelectric device.  
   
   
       10 . The damper control device of  claim 8  wherein power to run the comparator circuit is supplied by the battery.