Linear power supplies first reduce the amplitude of alternating current through a transformer, then rectify it through a rectifying circuit to obtain pulse direct current, which is subsequently filtered to produce a direct current voltage with minor ripple. To achieve high-precision direct current voltage, it must pass through a voltage regulation circuit for stabilization. Advantages of linear power supplies: stable performance with no high-frequency ripples or other interferences. Disadvantages of linear power supplies: heat generation and low energy utilization efficiency. Aeronautical Power Supply
Switched-mode power supplies, without the need for high-power sources, utilize modern power electronics technology to control the on-off time ratio of switching transistors, maintaining a stable output voltage. These power supplies are typically composed of pulse-width modulation (PWM) control ICs and MOSFETs. 400Hz power supply
Key Features:
1. Compact and Lightweight: Due to the absence of a power transformer, the size and weight are only 20-30% of that of a linear power supply. 2. Low Power Consumption and High Efficiency: Power transistors operate in a switching state, resulting in low power consumption on the transistors and high conversion efficiency, typically 60-70%, compared to only 30-40% for linear power supplies.
Switching Power Supply Operating Conditions:
1. Switching: Power electronic devices operate in a switching state rather than a linear state. 2. High-frequency: Power electronic devices operate at high frequencies rather than near the low-frequency industrial frequencies. 3. DC: Switched-mode power supplies output DC rather than AC. The voltage feedback circuit of a linear power supply operates in a linear (amplification) state, while a switched-mode power supply refers to tubes working in the saturation and cutoff regions, i.e., in the switching state. 36V Avionic Power Supply
