Power Board_Pcb2 Relay Boost Circuit (0558038315) - ESAB Powercut 1600 Service Manual

SECTION 4 DESCRIPTION Of OPERATION
4.10.14

Power Board_PCB2 Relay Boost Circuit (0558038315)

The Relay Boost circuit provides a source of power to trip the source voltage relays in the event that the AC
three phase input voltage is below 210 VAC in the 230 VAC mode.
In the event that the input power is low Q7 is turned on and conducts sending source voltage down to Q8.
The microcontroller gates on Q8 with a series of pulses that charge C84 to approximately 14 VDC. This al-
lows the 12 VDC relays to close in the voltage protection circuit.
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