Self-Configuring Ignition Controls

Abstract

A control for a gas fired heater is configurable to operate at either a first voltage or a second voltage higher than the first voltage. The control includes an input voltage measurement circuit and an automatic voltage select circuit. The input voltage measurement circuit is configured to be operable for measuring an input line voltage to determine whether the gas fired heater is connected with the first voltage or the second voltage. The automatic voltage select circuit is configured to be operable for configuring the control for the correct input line voltage as measured by the input voltage measurement circuit.

What is claimed is: 
     
         1 . A control for a gas fired heater that is configurable to operate at either a first voltage or a second voltage higher than the first voltage, the control comprising:
 an input voltage measurement circuit configured to be operable for measuring an input line voltage to determine whether the gas fired heater is connected with the first voltage or the second voltage; and   an automatic voltage select circuit configured to be operable for configuring the control for the correct input line voltage as measured by the input voltage measurement circuit.   
     
     
         2 . The control of  claim 1 , wherein the control is configured to be operable for automatically self-configuring itself for the correct input line voltage as measured by the input voltage measurement circuit. 
     
     
         3 . The control of  claim 2 , wherein the control is configured to be operable for automatically self-configuring itself for the correct input line voltage as measured by the input voltage measurement circuit without requiring manual input, without requiring a manual harness voltage selection and without requiring a PCB/edge connector jumper for the first and second voltages. 
     
     
         4 . The control of  claim 1 , wherein the control is configured to be operable for automatically routing a voltage output from a transformer of the gas fired heater based on the input line voltage as measured by the input voltage measurement circuit. 
     
     
         5 . The control of  claim 1 , wherein:
 the control is operable with a gas fired heater configurable to operate at either 120V or 240V;   the input voltage measurement circuit is operable for measuring input voltage level to determine whether the gas fired heater is connected with 120V service or 240V service; and   the automatic voltage select circuit is configured to be operable for automatically self-configuring the control correctly for the 120V service or 240V service based on the input line voltage as measured by the input voltage measurement circuit.   
     
     
         6 . The control of  claim 1 , wherein the control includes a transformer connector and a transformer voltage select relay, and wherein:
 the transformer connector and the input voltage measurement circuit are configured for connection with the transformer of the gas fired heater; and   the transformer voltage select relay is coupled with the transformer connector and the input voltage measurement circuit, the transformer voltage select relay operable for configuring transformer voltage output from the transformer connector based on the input line voltage as measured by the input voltage measurement circuit.   
     
     
         7 . The control of  claim 6 , wherein the control is configured such that the transformer voltage output from the transformer connector is automatically routed by the transformer voltage select relay based on the input line voltage as measured by the input voltage measurement circuit. 
     
     
         8 . The control of  claim 7 , wherein the control is configured such that the transformer voltage select relay is operable for automatically arranging two secondary 24V coils of the transformer of the gas fired heater:
 in parallel when 120V input line voltage is measured by the input voltage measurement circuit; and   in series when 240V input line voltage is measured by the input voltage measurement circuit.   
     
     
         9 . The control of  claim 8 , wherein the control includes a low voltage measurement circuit configured to confirm a 24VAC output of the two secondary 24V coils of the transformer of the gas fired heater. 
     
     
         10 . The control of  claim 6 , wherein the transformer voltage select relay is configured to be driven from the control voltage level thereby allowing for automatic self-reconfiguration when there is an incorrect configuration at startup. 
     
     
         11 . The control of  claim 1 , wherein the control is configured to be operable for automatically self-selecting a correct voltage level for the gas fired heater without manual intervention and to indicate when something is amiss including when there is an incorrect configuration at startup. 
     
     
         12 . The control of  claim 11 , wherein the control is configured to generate an alert or warning when something is amiss including when there is an incorrect configuration at startup. 
     
     
         13 . The control of  claim 1 , wherein:
 the gas fired heater comprises a burner coupled with a gas valve, a hot surface ignitor, an inducer fan for the burner, and a transformer;   the control comprises an inducer fan control relay and a flame sense;   the control is configured such that the input line voltage is operable for:   supplying a voltage power supply to the inducer fan control relay and to the transformer of the gas fired heater; and   driving the flame sense, the hot surface ignitor, and the inducer fan for the burner.   
     
     
         14 . The control of  claim 1 , wherein:
 the control includes a flame sense; and   the control is configured such that thresholds of the flame sense are configured to account for different input voltages.   
     
     
         15 . The control of  claim 1 , wherein:
 the control includes an ignitor circuit and a triac; and   the ignitor circuit is configured to modulate an effective RMS power to an ignitor of the gas fired heater by using the triac to remove a section of each half cycle, whereby an amount of on/off time for the triac is determinable via a lookup table based upon the input voltage level.   
     
     
         16 . The control of  claim 1 , wherein the control includes:
 a fan connector configured for connection with an inducer fan for a burner of the gas fired heater;   an inducer fan control relay electrically connected with the fan connector and the input voltage measurement circuit;   an ignitor triac wave chopper configured for connection with an ignitor of the gas fired heater; and   an inducer fan circuit including a voltage routing relay, the voltage routing relay is coupled with the inducer fan control relay, the ignitor triac wave chopper, an input voltage line, and the fan connector.   
     
     
         17 . The control of  claim 16 , wherein the control is configured such that:
 when 240V input line voltage is measured by the input voltage measurement circuit, a normally closed contact of the voltage routing relay is configured to route 240V voltage level; and   when 120V input line voltage is measured by the input voltage measurement circuit, the voltage routing relay is energized to route the inducer fan for 120V operation prior to energizing the inducer fan control relay.   
     
     
         18 . The control of  claim 1 , wherein the control is a 120V/240V automatic self-configuring combined ignition and controller for a hot surface ignition (HSI) system. 
     
     
         19 . A hot surface ignition (HSI) system for a gas fired heater, the hot surface ignition system comprising the control of  claim 1 . 
     
     
         20 . A gas fired heater comprising the control of  claim 1 , wherein the control includes a user interface including a display that allows a user to increase or decrease a temperature setpoint of the gas fired heater. 
     
     
         21 . A method for automatically self-configuring a control for a gas fired heater that is configurable to operate at either a first voltage or a second voltage higher than the first voltage, the method comprising:
 measuring an input line voltage via an input voltage measurement circuit to determine whether the gas fired heater is connected with the first voltage or the second voltage; and   automatically self-configuring the control via an automatic voltage select circuit for the correct input line voltage as measured by the input voltage measurement circuit.   
     
     
         22 . The method of  claim 21 , wherein the method includes automatically self-configuring the control via the automatic voltage select circuit without manual input to select the correct input line voltage. 
     
     
         23 . The method of  claim 21 , wherein the method includes automatically self-configuring the control via the automatic voltage select circuit for the correct input line voltage as measured by the input voltage measurement circuit without requiring a manual harness voltage selection, without requiring a PCB/edge connector jumper for the first and second voltages, and without requiring an installer or technician to manually select a correct multi-pin connector based jumper for the gas fired heated based on the specific incoming voltage level.