TABLE V. Functions of Electronic Components (Figs. 7 & 9)
Components
Symbol
Function
(.001 mf, 600 WVDC) thyratron g-rid capacitor prevents thyratron
C101
Capacitors
from firing due to undesirable voltages inthyratrongrid circuit.
(10 mf, 450 WVDC) filter capacitor for output of full-wave rectifier
C102
VI 02.
C103
(0.5 mf, 600 WVDC)used with resistors R108 and R109 to improve
C104
response of motor to sudden changes in load or wire feed speed.
(10-amp) in 115 V, 60 cps input lines to protect Control circuits
F101
Fuses
against overloading.
F102
(1/4-amp) protects full-wave rectifier V102.
F103
IL
Glows when main power switch SW101 is ON.
Indicator
(8 henrys) filters AC ripple from rectifier V102 output.
L101
Inductor
(Single-pole, double-throw) current relay, picks up at approximately
Relays
CR101
100 amperes when weld power source current flows in welding
circuit; energizes CR102 for "scratch-start".
(Double-pole, double-throw) picks up at about 11 volts to energize
CR102
C R 1 0 5 during "scratch-start" operation.
(Four-pole, double-throw) weld relay, energized when gun trigger
CR103
is depressed; energizes TDR101 for gas and water flow, WC relay
for weld current, and CR105 for operation of wire feed motor.
(Four-pole, double-throw) picks up when wire jog on gun is de-
CR104
pressed to energize CR105 to enable wire feed without gas and
water flow.
(Four-pole, double-throw) picks up when gun trigger or wire jog is
CR105
depressed to operate wire feed motor by placing motor armature in
series with field; when trigger or jog is released, places armature
in parallel with field for dynamic braking.
TDR101
(Single-pole, double-throw) pneumatic off-relay; energizes gas and
water solenoids in Wire Feeder to apply shielding gas and cooling
water at gun; also times and limits post-weld flow of gas and
water.
R101
(4000 ohms, 5 watts, fixed) In series with AC winding of saturable
Resistors
reactor SX101 to supply a phase-shifted voltage to thyratron V101.
Amount of phase-shift determines wire feed motor speed.
R102
(220, 000 ohms, 1 watt, fixed) Limits current to grid of thyratron
Viol.
(50
R103
watts, 125 volt, lamp bulb) Used in dynamic braking at end of
weld cycle when gun trigger is released.
72