Switching power supplies are used as replacements for linear regulators when higher efficiency, smaller size, or lighter weight are required. The main advantage of a switching power supply is greater efficiency than linear power supplies because the switching transistor dissipates little power when acting as a switch. Switching power supplies are better suited for handheld devices when battery life and efficiency are important.
A switching power supply can be used:
- For transforming high voltage to lower voltage (typically 120 VAC to lower voltage DC power)
- When a smaller footprint and lighter weight is needed or required
- When low cost and low heat output is desired
- When high efficiency is required
- When wireless door controller devices are not being utilized. (Switching power supplies emit EMI noise.)
- When step-down power regulation is required
A linear power supply requires larger semiconductor devices to regulate the output voltage and therefore generates more heat, resulting in lower energy efficiency. A linear power supply normally operates around 60% efficiency for 24V outputs. A switching power supply operates at 80% efficiency or more.