Theory of operation, Power supply operation (continued), Wire drive motor and feedback – Lincoln Electric IDEALARC SP-250 Manuel d'utilisation
Page 44: E-4 idealarc sp-250
E-4
THEORY OF OPERATION
E-4
IDEALARC SP-250
WIRE DRIVE MOTOR AND FEEDBACK
The wire drive motor is controlled by the control board.
A motor speed feedback signal is generated at the
motor tach and sent to the control board. The control
board compares this feedback signal with the com-
mands set forth by the keypad (or the gun thumb
switch) and sends the appropriate armature voltage to
the wire drive motor. The drive motor speed is thus
controlled which in turn regulates the electrode wire
feed speed through the gun.
Figure E.5 - Wire Drive Motor and Feedback
POWER SUPPLY OPERATION (CONTINUED)
LINE
SWITCH
MAIN
TRANSFORMER
RECONNECT
FAN
MOTORS
SCR
RECTIFIER
C
A
P
A
C
I
T
O
R
S
SHUNT
CHOKE
WIRE
DRIVE
MOTOR
TACH
POSITIVE
TERMINAL
NEGATIVE
TERMINAL
GAS
SOLENOID
PIEZO
ALARM
KEYPAD
CONTROL BOARD
FEEDBACK
GUN TRIGGER AND THUMB SWITCH
F
E
E
D
B
A
C
K
G
A
T
E
I
G
N
S
A
L
LCD
DISPLAY
NOTE: Unshaded areas of Block Logic
Diagram are the subject of discussion