Question
Download Solution PDFA voltage regulator gives 5 V output when 10 V is applied to input. What is the input current when the load current of 0.75 A flows assuming an efficiency of 75% ?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFExplanation:
The efficiency of a voltage regulator is defined as the ratio of output power to input power, expressed as a percentage:
Efficiency (%) = (Output Power / Input Power) × 100
Rearranging this formula, we can calculate the input power:
Input Power = Output Power / Efficiency
Next, we use the relationship between power, voltage, and current to determine the input current:
Power = Voltage × Current
Rearranging this, the input current can be calculated as:
Input Current = Input Power / Input Voltage
Solution:
The output power is the product of the output voltage and the load current:
Output Power = Output Voltage × Load Current
Here, the output voltage is 5 V, and the load current is 0.75 A.
Output Power = 5 × 0.75 = 3.75 W
Using the efficiency formula, we calculate the input power. The efficiency is given as 75%, or 0.75 in decimal form:
Input Power = Output Power / Efficiency == 3.75 / 0.75 = 5 W.
Using the relationship between power, voltage, and current, we find the input current. The input voltage is 10 V:
Input Current = Input Power / Input Voltage = 5/10 = 0.5 A
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