A DC welding power source has a linear voltagecurrent (V-I)

A DC welding power source has a linear voltagecurrent (V-I) characteristic with open circuit voltage of 80 V and a short circuit current of 300 A. For maximum arc power, the current (in Ampere) should be set as______.

Constant Voltage characteristics

150A = v_ocV −		v_ocV		I
		1_scc

V = 80 −		80		I
		300

P = V I

=		80 −		80		I		I
				300

For Maximum Power

dP	= 0
dI

80 – 2 × 0.666 I = 0
I = 150A