Thermistor protection for a wire feed motor
First Claim
1. A wire feeder for arc welding comprising:
- a wire feed motor;
a power supply, in electrical communication with the wire feed motor;
a PTC thermistor disposed electrically between the power supply and the wire feed motor.
1 Assignment
0 Petitions
Accused Products
Abstract
A system for arc welding includes a welding power supply and a wire feeder. The wire feeder includes a dc wire feed motor and a dc wire feed power supply in electrical communication with the wire feed motor. A PTC thermistor is disposed electrically between the power supply and the wire feed motor. Current flows from the power supply, through the PTC thermistor, and then to the motor. Under normal current conditions the PTC thermistor allows current to be provided to the wire feed motor from the power supply, but under excessive current conditions the PTC thermistor inhibits current from being provided to the wire feed motor from the power supply. A diode is connected in anti-parallel with the motor. A pulse width modulation switch control current delivered to the motor. A normally open relay is closed when welding is to be performed to provide current to the motor, and a normally closed relay, connected in parallel with and shunting the motor, is opened when welding is to be performed. The normally closed relay acts as a brake on the motor when it is closed. The PTC thermistor is not shunted by a resistor and/or a varistor, and/or is not in parallel with a relay.
27 Citations
32 Claims
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1. A wire feeder for arc welding comprising:
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a wire feed motor;
a power supply, in electrical communication with the wire feed motor;
a PTC thermistor disposed electrically between the power supply and the wire feed motor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A wire feeder for arc welding comprising:
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motor means for feeding wire;
power means for providing power to the motor means, wherein the power means is in electrical communication with the wire feed motor;
a PTC thermistor means for protecting the motor means, wherein the PTC thermistor means is disposed electrically between the power means and the motor means. - View Dependent Claims (14, 15, 16)
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17. A system for arc welding comprising:
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a welding power supply, disposed to provide power to an arc a wire feed motor, disposed to provide wire to an arc;
a wire feed power supply, in electrical communication with the wire feed motor;
a PTC thermistor disposed electrically between the wire feed power supply and the wire feed motor. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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29. A system for arc welding comprising:
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welding power means for providing power to an arc;
motor means for feeding wire to the arc;
wire feed power means for providing power to the motor means, wherein the wire feed power means is in electrical communication with the wire feed motor;
a PTC thermistor means for protecting the motor means, wherein the PTC thermistor means is disposed electrically between the wire feed power means and the motor means. - View Dependent Claims (30, 31, 32)
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Specification