ESAB Powercut 650 Especificações descarregar pdf (Página 58)

SECTION 5 MACHINE TESTING / TROUBLESHOOTING / SERVICE

5.8.9 Over / Under Voltage Fault Circuit

The PCB Control board has a voltage monitoring circuit and major fault logic built onto it.

IC3 is a voltage comparator circuit, which monitors the unregulated voltage that feeds the positive 12

and 15 volt supplies. If the voltage dips below 11.8VDC IC3 sends an error signal to IC2 pin 4 and this

signal sets the fault on IC2 pin 6 turning on Q5 and Q6. This turns on the under voltage/over voltage fault

LED on the front panel. This shows on the front panel as a ashing light.

From the same unregulated reference point on the positive 12 and 15-volt bias supplies, the over voltage

sense circuit is monitored. This involves the voltage being input on IC2 pin 17 where it is monitored and

when it reaches 25VDC this will set the fault on IC2 pin 6 turning on Q5 and Q6. This turns on the under

voltage/over voltage fault LED on the front panel. This shows on the front panel as a ashing light.

Lastly, IC2 monitors the state of the PCB itself and in the event of a major fault, it will initiate turning on

the fault by setting IC2 pin 6 high and turning on Q5 and Q6. This turns on the under voltage/over volt-

age fault LED on the front panel. This shows on the front panel as a steady light.

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ESAB Powercut 650 Especificações Página 58