Method And Apparatus For Receiving A Universal Input Voltage In A Welding Power Source

Abstract

A method and apparatus for providing a welding current is disclosed. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A dc voltage stage converts the dc signal to a desired dc voltage and an inverter inverts the dc signal into a second ac signal. An output transformer receives the second ac signal and provides a third ac signal that has a current magnitude suitable for welding. The welding current may be rectified and smoothed by an output inductor and an output rectifier. A controller provides control signals to the inverter and an auxiliary power controller that can receive a range of input voltages and provide a control power signal to the controller.

1 . A welding power source capable of receiving a range of input voltages, comprising:
 an input rectifier configured to receive an ac input and providing a first dc signal;   a dc voltage stage configured to receive the first dc signal and providing a second dc signal;   an inverter configured to receive the second dc signal and providing a second ac signal and configured to receive at least one control input;   an output transformer configured to receive the second ac signal and providing a third ac signal having a current suitable for welding;   an output circuit configured to receive the third ac signal and providing a welding signal;   a controller configured to provide at least one control signal to the inverter; and   an auxiliary power controller configured to receive a range of input voltages and providing a control power signal to the controller.   
   
   
       2 . The apparatus of  claim 1 , wherein the auxiliary power controller is capable of providing the control power signal at a preselected control signal voltage, regardless of the magnitude of the ac input signal. 
   
   
       3 . The apparatus of  claim 2 , further including an auxiliary transformer with a plurality of primary taps, wherein the auxiliary power controller is in electrical communication with the plurality of primary taps. 
   
   
       4 . The apparatus of  claim 1 , wherein the dc voltage stage includes a boost circuit. 
   
   
       5 . The apparatus of  claim 1 , wherein the inverter includes a pulse width modulator. 
   
   
       6 . The apparatus of  claim 1 , wherein the range of input voltages is 230 volts to 575 volts. 
   
   
       7 . The apparatus of  claim 1  wherein the output circuit includes a rectifier. 
   
   
       8 . The apparatus of  claim 1  wherein the output circuit includes a cycloconverter. 
   
   
       9 . A method of providing a welding current from a range of input voltages, comprising:
 rectifying an ac input and providing a first dc signal;   converting the dc signal to a second ac signal;   transforming the second ac signal into a third ac signal having a current suitable for welding; and   receiving the ac input and providing an auxiliary power signal source at a preselected control power signal voltage, regardless of the magnitude of the ac input signal.   
   
   
       10 . The method of  claim 9 , wherein the step of converting the dc signal includes the steps of converting the dc signal to a second dc signal and inverting the second dc signal to provide the second ac signal. 
   
   
       11 . The method of  claim 9  further including the step of providing control signals to an inverter. 
   
   
       12 . The method of  claim 9 , wherein the step of providing the auxiliary power signal includes the step of transforming the ac input signal. 
   
   
       13 . The method of  claim 10 , wherein the step of converting the first dc signal to a second dc signal includes boosting the voltage of the first dc signal. 
   
   
       14 . The method of  claim 10 , wherein the step of inverting includes the step of pulse width modulating. 
   
   
       15 . The method of  claim 10  further including the step of rectifying the third ac signal. 
   
   
       16 . The method of  claim 10  further includes the step of cycloconverting the third ac signal. 
   
   
       17 . A welding power source for providing a welding current from a range of input voltages, comprising:
 rectifier means for receiving an ac input and providing a first dc signal;   converting means for converting the dc signal to a second ac signal;   transforming means for transforming the second ac signal into a third ac signal having a current suitable for welding;   output means for providing a welding current; and   auxiliary power means for receiving the ac input and providing an auxiliary power signal at a preselected control power signal voltage, regardless of the magnitude of the ac input signal.   
   
   
       18 . The apparatus of  claim 17 , wherein the means for converting includes means for converting the dc signal to a second dc signal and means for inverting the second dc signal to provide the second ac signal. 
   
   
       19 . The apparatus of  claim 17  further including means for providing control signals to an inverter. 
   
   
       20 . The apparatus of  claim 17 , wherein the means for providing the auxiliary power signal includes means for transforming the ac input signal into the auxiliary power signal. 
   
   
       21 . The apparatus of  claim 17 , wherein the means for converting the dc signal to a second dc signal includes means for boosting the voltage. 
   
   
       22 . The apparatus of  claim 17 , wherein the means for inverting includes means for pulse width modulating. 
   
   
       23 . The apparatus of  claim 17 , wherein the output means includes means for rectifying the third ac signal. 
   
   
       24 . The apparatus of  claim 17 , wherein the output means includes means for cycloconverting the third ac signal.