-3-
ANALYSIS OFTHE BLOCK DIAGRAM
NOTE: Unless indicated otherwise, it should be assumed that
thecomponentsareassembledontheweldingmachine.
Consistingof:C3,R5,L1,C8,C9 .
Preventsnoisefromthemachinefrombeingtransmittedalong
themainpowerlineandviceversa.
Consistingof:Q1,Q2,Q3,Q4
Converts the continuous voltage from the filter into a high
frequency square wave capable of piloting the power
transformer.
Regulates the power according to the required welding
current/voltage.
Consistingof:T1 .
TheC.T.isusedtomeasurethecurrentcirculatinginthepower
transformer primary and transmit the information to block 14
(primarycurrentreaderandlimiter).
Consistingof:T1.
Adjusts the voltage and current to values required for the
welding procedure. Also forms galvanic separation of the
primary from the secondary (welding circuit from the power
supplyline).
Block 1
Block 2
Block 5
Block 6
Block 7
Block 8
EMC Filter
Chopper
Current transformer
Power transformer
(primaryboard)
Consistingof:D3,D5(primaryboard).
Converts the alternating mains voltage to continuous pulsed
voltage NoD3presentonTechnology150).
Consistingof:K1,K2,R1(primaryboard).
Prevents the formation of high transient currents that could
damage the main switch, the rectifier bridge and the
electrolytic capacitors.When the power source is switched on
relaysK1andK2arede-energised,capacitorsC2,C4,C5,C6,
C7 are therefore charged via R1. When the capacitors are
charged the relay will be energised. ( No K2 present on
Technology150).
Consistingof:C2,C4,C5,C6,C7(primaryboard).
Converts the pulsed voltage arriving from the rectifier bridge
to continuous voltage ( No C7 present on Technology
150).
(primaryboard).
(primaryboard)
Consistingof:D1,D2,D3,D5(secondaryboard).
- D1and D2 convert thecurrentcirculating in thetransformer
to a single direction, preventing saturation of the nucleus.
:NoD2onTechnology150).
Rectifier bridge
Pre-charge
Filter
Secondary diodes
(N.B.
N.B.
N.B.
(N.B.
Block 3
Block 4
- D3, D5 recirculate the inductance output current (block 9)
during the time when the IGBT's are not conducting,
bypassingthepowertransformer(block7).
Consistingof:L1,R1.
The inductance levels the output current from the secondary
boarddiodesmaking it practicallydirect.The shunt detects the
currentcirculatinginthesecondaryandsendsavoltagesignal
toblock16(adder),whichwillprocessit.
Inductance and Shunt
hybridboard.
block 14 (duty
cyclemaker).
Block 9
Block 10
Block 11
Block 12
Block 13
Block 14
Block 15
Block 16
Secondary EMC Filter
Flyback power supply
IGBT Driver
Primary current reader and limiter
Duty cycle maker
Adder
Alarm Block
Consistingof: CY1,CY2.
Prevents noise from the power source from being transmitted
throughtheweldingcablesandviceversa.
Consistingof:T2,U2(primaryboard).
Uses switching methods to transform and stabilise the voltage
obtained from block 4 (filter) and supplies auxiliary voltage to
powerblock12(driver)andthe
Consistingof:U1A,U1D(primaryboard).
Takes the signal from block 11 (flyback power supply) and,
controlled by block 14 (duty cycle maker), makes the signal
suitableforpilotingblock6(chopper).
Consistingof: R15(primaryboard).
Readsthesignalfromblock6(currenttransformer)andscales
itdownso it canbeprocessed and comparedin
Consistingof:U2(hybridboard).
Processes the information from block 15 (adder) and block 13
(primary current reader and limiter) and produces a square
wave with variable duty cycle limiting the primary current to a
maximumpre-setvalueunderallcircumstances.
Consistingof:U1A,U1D(hybridboard).
Gathers all the information from block 13 (primary current
reader and limiter), from block 16 (alarms) and from block 18
(current potentiometer), and produces a signal with a suitable
voltageforprocessingbyblock14(dutycyclemaker).
Consistingof:Q5,R11,R14,R17(controlboard).
When an alarm is detected the power source output current is
drastically reduced by making direct adjustments to block 14
(duty cycle maker) and directly changing the reference signal
obtainedfromblock18(currentpotentiometer).
TECHNOLOGY 150-170-200-186CE/GE
TECHNOLOGY 150-170-200-186CE/GE
