Thepry - 30 :- Specifications of a regulated power supply and testing a power supply for its specifications.

A Regulated Power Supply is designed to provide a constant DC output voltage (or current) regardless of variations in the AC input (line) voltage or changes in the output load current. This stability is critical for reliably powering sensitive electronic circuits and devices. 

1. Specifications of a Regulated Power Supply

The quality and performance of a regulated power supply are defined by several key specifications.

A. Voltage Stability

• Nominal Output Voltage and Maximum Current: The specified DC voltage (e.g., 5V, 12V) and the maximum current (e.g., 1 A, 5 A) it can reliably deliver.

• Load Regulation (LR): A measure of the power supply's ability to maintain a constant output voltage despite changes in the load current (from no-load to full-load). An ideal power supply has 0% load regulation.

C. Testing Line Regulation

1. Set the output load to the nominal load (usually full-load or a specific percentage).

2. Set the AC input voltage to its maximum operating value, measure and record the output voltage $V_{\text{HL}}$.

3. Set the AC input voltage to its minimum operating value, measure and record the output voltage $V_{\text{LL}}$.

4. Calculate the percentage line regulation using the formula:

D. Testing Ripple and Noise (PARD)

1. Set the input voltage and output load to the conditions specified in the datasheet (e.g., full-load, nominal line).

2. Connect an oscilloscope (usually set to a 20 MHz bandwidth limit) across the output terminals.

3. Measure the peak-to-peak voltage (mVp-p) of the AC component observed on the DC output. Use short measurement leads or specialized probe techniques to minimize induced noise.