Device and method to control a power source
First Claim
1. A device for providing a voltage reduction capability in a welding power source, said device comprising:
- means for inducing an oscillating signal, from within a welding power source, in an output current path of said welding power source;
means for sensing said induced oscillating signal, from within said welding power source, to generate a sensed signal being indicative of a load condition or a no-load condition between an electrode output terminal and a workpiece output terminal of said welding power source;
means for detecting an RMS output voltage, from within said welding power source, being indicative of a low output voltage condition or a high output voltage condition across said electrode output terminal and said workpiece output terminal; and
means for disabling an input power side of said welding power source, from within said welding power source, when said sensed signal is indicative of a no-load condition and said RMS output voltage is indicative of a high output voltage condition,wherein said means for disabling said input power side of said welding power source is realized by automatically opening a VRD switch on said input power side that is in series with a main ON/OFF switch of said welding power source and a coil of an input power contact relay of said welding power source.
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Accused Products
Abstract
Apparatus, devices, and methods for providing a voltage reduction capability in a welding power source for safety purposes. The resistive load and the output voltage of the welding power source output are monitored and compared to predefined or preselected threshold values to generate a load condition signal and an output voltage condition signal (e.g., logic signals). The load condition signal and the output voltage condition signal serve as inputs to a voltage reduction device control logic which generates control signals to enable and disable the input and output of the welding power source according to the defined control logic. As a result, an extra measure of safety in preventing electrical shock is provided to users of the welding power source during hazardous operating conditions.
38 Citations
19 Claims
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1. A device for providing a voltage reduction capability in a welding power source, said device comprising:
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means for inducing an oscillating signal, from within a welding power source, in an output current path of said welding power source; means for sensing said induced oscillating signal, from within said welding power source, to generate a sensed signal being indicative of a load condition or a no-load condition between an electrode output terminal and a workpiece output terminal of said welding power source; means for detecting an RMS output voltage, from within said welding power source, being indicative of a low output voltage condition or a high output voltage condition across said electrode output terminal and said workpiece output terminal; and means for disabling an input power side of said welding power source, from within said welding power source, when said sensed signal is indicative of a no-load condition and said RMS output voltage is indicative of a high output voltage condition, wherein said means for disabling said input power side of said welding power source is realized by automatically opening a VRD switch on said input power side that is in series with a main ON/OFF switch of said welding power source and a coil of an input power contact relay of said welding power source. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An apparatus for providing a voltage reduction capability in a welding power source, said apparatus comprising:
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a tuned receiver circuit configured within said welding power source to receive an oscillating signal induced in a welding output current path within said welding power source and to generate a logical load condition signal therefrom; a voltage sensing circuit configured within said welding power source to detect a voltage between an electrode output terminal and a workpiece output terminal of said welding power source and to generate a logical output voltage condition signal; a voltage reduction device (VRD) switch in series with a main ON/OFF switch of said welding power source and a coil of an input power contact relay of said welding power source on an input power side of said welding power source; and a voltage reduction device (VRD) control logic circuit configured within said welding power source to open said VRD switch when said logical load condition signal indicates a no-load condition and said logical output voltage condition signal indicates a high output voltage condition. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method of providing a voltage reduction capability in a welding power source, said method comprising:
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sensing an induced signal, within a welding power source, to generate a sensed signal being indicative of a load condition or a no-load condition between an electrode output terminal and a workpiece output terminal of said welding power source; detecting an output voltage, within said welding power source, being indicative of a low output voltage condition or a high output voltage condition across said electrode output terminal and said workpiece output terminal; and disabling an input power side of said welding power source, within said welding power source, by automatically opening a VRD switch on said input power side that is in series with a main ON/OFF switch of said welding power source and a coil of an input power contact relay of said welding power source, when said sensed signal is indicative of a no-load condition and said output voltage is indicative of a high output voltage condition. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification