Miller Electric BLUE STAR 6000 TM-499C User Manual
Page 31
TM-499 Page 27
PART NAME
CIRCUIT SYMBOL
PICTURE
FUNCTION
MOTOR
A device that converts electrical energy into
mechanical energy. Typically used to feed
wire in a MIG welding system, or pump
coolant in a recirculating liquid-cooling
system.
M1
M1
= DC
= AC
OPERATIONAL
AMPLIFIER
Usually referred to as an “Op-Amp”, this IC
chip is very versatile and widely used on PC
boards. A typical use might be as a
“comparator”, comparing the command
signal to the feedback signal allowing the
welding output to be kept constant.
A1
+
_
OPTICAL
COUPLER
A device that uses “light” to get electrical
separation (isolation). This eliminates noise
that might be in one circuit from affecting
another circuit.
OC1
PILOT LIGHT
A light located on the front panel which
indicates if the machine is on or off.
PL
1
POTENTIOMETER
OR
RHEOSTAT
Both devices have a moveable brush that
makes contact along a resistor, allowing you
to easily change the resistance measured at
the brush (sometimes referred to as a wiper).
Their primary purpose is to give the operator
a way to adjust welding parameters such as
wire speed, preflow time, voltage,
inductance, etc.
CW = CLOCKWISE
R1
CCW =COUNTER-
CLOCKWISE
PLUG
A connection device that hangs loose with
wires coming out the back of it. Please note
that the plug terminals can be either male or
female.
PLG1
PLG =
LOOSE
MALE
FEMALE
RECEPTACLE
A connection device that is mounted or fixed.
Just like a plug, the terminals can be either
male or female.
RC1
RC =
MOUNTED
MALE
FEMALE
RELAY−−COIL AND
CONTACTS,
NORMALLY OPEN
AND NORMALLY
CLOSED
This is an electromechanical device whose
contacts change state (the normally open
points close and the normally closed points
open) when proper voltage is applied to the
coil. These contact points in turn may control
a fan motor, gas solenoid, contactor, etc.
Circuit diagrams (schematics) always show
the contact points in the power off state.
CR1
CR1
COIL
NRM OPEN
POINTS
NRM CLOSED
POINTS
CR1
RESISTOR
A device which resists the flow of electric
current. Uses include limiting the current for a
motor brake circuit in a wire feeder and for
discharging a capacitor.
FIXED
FIXED TAPPED
R1
R1
RIBBON CABLE
A connection device where the wires are laid
out flat. Usually to connect circuits from one
PC board to another PC board.
26-CONDUCTOR
CABLE
RC54
RC44