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Kemppi OY
5. SECONDARY CUT OFF CARD Z004
• Secondary cut-off card Z004 is used to make special welding characteristics. There is a need of a very quick current
cut-off in a certain stage in PipeRoot welding process
• Mosfets V6-V45 are controlled to non-conductive state while the certain very short time period
• In order to control those mosfets they need isolated voltage from secondary shunt-, because mosfets sources are
connected to main choke+. The isolated voltage +15Vdc in C7 is generated from +24Vdc by using forward converter
with V1 and T1. Control gate signal is generated in the processor card A002 isolated from the mosfet gates through an
optical driver H1
• A resistor R004 is used to reduce voltage spikes while those PipeRoot periods
• The whole secondary current goes through secondary profile between rectifier card Z003 and cut-off card Z004
5.1. Connectors
Connector Description
X1:1 Optical coupler anode
X1:2 Optical coupler cathode
X1:3 Not in use
X1:4 +24Vdc
X1:5 FET FAILURE signal
X1:6 GND
X5-X8 Secondary choke