TOC
TOC
.THEORY OF OPERATION | ||
| FIGURE E.4 – WIRE FEED SPEED CONTROL & FEEDBACK |
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ELECTRODE INPUT VOLTAGE
TOROID
ASSEMBLY
FULL
WAVE
BRIDGE
CONTACTOR
| FEED | WELDING | |
| PLATE |
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GAS | M |
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SOLENOID | O | HALL | |
T | |||
"ELECTRODE" | EFFECT | ||
O | |||
FEEDBACK | R | MODULE | |
VOLTAGE #67 |
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ARMATURE
RPM FEEDBACK
ON/OFF
SWITCH
MOV
WORK SENSING LEAD
BOOST POWER SUPPLY BOARD
FEED HEAD BOARD SUPPLY
DRIVE MOTOR SUPPLY
FEED HEAD
CONTROL BOARD
"WORK" VOLTAGE FEEDBACK #21
SPI COMMUNICATIONS
SHIELDED CABLE
COLD | WIRE | TRIGGER | TRIGGER | DISPLAY | |
INPUT & | INTERLOCK | ||||
INCH | FEED | BOARD | |||
PROCEDURE | SWITCH | ||||
SWITCH | SPEED |
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| CONTROL |
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WIRE FEED SPEED CONTROL AND | ule and the arc voltage. These three factors are com- | |
FEEDBACK | pared and the appropriate armature voltage is applied | |
to the wire feed motor to compensate for the varying | ||
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The combination of the Procedure Switch and the Wire | arc lengths and associated arc voltages. | |
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Feed Speed control provide a command voltage for |
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the Feed Head Control Board. The Hall Effect module |
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(Tach) monitors the motor RPM and outputs a digital |
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voltage frequency “feed back” that is delivered to the |
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Feed Head Board. |
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When operating in the constant voltage (CV) mode the |
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Feed Head Board monitors the feedback signal and |
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compares it to the command voltage and delivers the |
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appropriate armature voltage to the wire feed motor. |
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In this manner a constant wire feed speed is main- |
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tained. |
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When the
(CC)power source a variable wire feed speed is desir- able to compensate for the varying arc voltages asso- ciated with the constant current process. To accom- plish this the Feed Head Board monitors the command voltage, the feed back signal from the Hall Effect mod-
NOTE: Unshaded areas of Block Logic Diagram are the subject of discussion.
