Which of the following is characteristic of a switchmode power supply as compared to a linear power supply?
The correct answer is C: High-frequency operation allows the use of smaller components. A characteristic of a switchmode power supply as compared to a linear power supply is that high-frequency operation allows the use of smaller components. Switchmode supplies operate at high frequencies (kHz to MHz), allowing smaller transformers and capacitors. For amateur radio operators, this makes switchmode supplies more compact. Understanding this helps when selecting power supplies.
Exam Tip
Switchmode advantage = high-frequency operation allows smaller components. Think 'S'witchmode = 'S'maller components at 'S'witching frequencies. High-frequency operation (kHz-MHz) allows smaller transformers and capacitors. Not higher voltage, not fewer components, not more stable - just smaller components.
Memory Aid
"Switchmode advantage = high-frequency operation allows smaller components. Think 'S'witchmode = 'S'maller components. High-frequency operation (kHz-MHz) allows smaller transformers and capacitors. Makes switchmode supplies more compact."
Real-World Application
A switchmode power supply operates at 100 kHz, while a linear supply operates at 60 Hz. The high-frequency operation allows the switchmode supply to use much smaller transformers and capacitors for the same power output. This makes switchmode supplies more compact and lighter than linear supplies.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Faster switching doesn't make higher output voltage possible - voltage is determined by design, not switching speed. Higher voltage isn't the advantage.
Option B: Incorrect. Switchmode doesn't require fewer components - it often requires more components (switches, control circuits). Fewer components isn't the advantage.
Option D: Incorrect. Switchmode isn't inherently more stable - linear supplies are often more stable. Stability isn't the advantage.
题目解析
The correct answer is C: High-frequency operation allows the use of smaller components. A characteristic of a switchmode power supply as compared to a linear power supply is that high-frequency operation allows the use of smaller components. Switchmode supplies operate at high frequencies (kHz to MHz), allowing smaller transformers and capacitors. For amateur radio operators, this makes switchmode supplies more compact. Understanding this helps when selecting power supplies.
考试技巧
Switchmode advantage = high-frequency operation allows smaller components. Think 'S'witchmode = 'S'maller components at 'S'witching frequencies. High-frequency operation (kHz-MHz) allows smaller transformers and capacitors. Not higher voltage, not fewer components, not more stable - just smaller components.
记忆口诀
Switchmode advantage = high-frequency operation allows smaller components. Think 'S'witchmode = 'S'maller components. High-frequency operation (kHz-MHz) allows smaller transformers and capacitors. Makes switchmode supplies more compact.
实际应用示例
A switchmode power supply operates at 100 kHz, while a linear supply operates at 60 Hz. The high-frequency operation allows the switchmode supply to use much smaller transformers and capacitors for the same power output. This makes switchmode supplies more compact and lighter than linear supplies.
错误选项分析
Option A: Incorrect. Faster switching doesn't make higher output voltage possible - voltage is determined by design, not switching speed. Higher voltage isn't the advantage. Option B: Incorrect. Switchmode doesn't require fewer components - it often requires more components (switches, control circuits). Fewer components isn't the advantage. Option D: Incorrect. Switchmode isn't inherently more stable - linear supplies are often more stable. Stability isn't the advantage.
知识点
Switchmode power supply, High-frequency operation, Smaller components, Linear vs switchmode
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.