Question

The specification for a very large DC power supply is 2.18 megavolts at 0.18 amperes with a ripple factor of 0.1% and a regulation of 0.05%. Assuming any ripple is due solely to a 400 Hertz sinusoid, calculate: a. The maximum RMS value of the ripple voltage, VAC b. The No-Load voltage of the power supply

Answer 1

Given Information:

Vdc = VF-L = 2.18x10⁶ V = 2,180,000 V

VF-L = voltage at full load

Ripple factor = r = 0.1 %

Voltage Regulation = VR = 0.05 %

Required Information:

Ripple voltage = Vr = ?

No-Load Voltage = VN-L = ?

Answer:

a. Ripple voltage = Vr = 2,180 V

b. No-Load Voltage = VN-L = 2,181,090 V

Solution:

a. Ripple Voltage Vr

The ripple factor is a measure of effectiveness of the rectification (the conversion of AC to DC) and it should be as low as possible.

The ripple factor is given by

r = Vr/Vdc

Re-arranging the formula to find ripple voltage Vr

Vr = Vdc*r

Vr = (2.18x10⁶)*0.001

Vr = 2,180 V

b. No-Load Voltage VN-L

Voltage regulation is given by

VR = (VN-L - VF-L)/VF-L

Re-arranging the formula to find the no-load voltage VN-L

VN-L = VR*VF-L + VF-L

VN-L = 0.0005*2.18x10⁶ + 2.18x10⁶

VN-L = 1090 + 2.18x10⁶

VN-L = 2,181,090 V

VN-L = 2.181x10⁶ V