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All colleagues unite and focus their efforts to write a new chapter of developmentWhat is the structure of a power adapter?
所属分类： Industry News
发布时间：2020-06-15
Everyone is surely well aware that what we often talk about is…
Power adapter There are two main categories: linear power adapters and switching power adapters. Linear power adapters are relatively simpler, typically consisting of a single low‑frequency transformer; however, this configuration only steps down the voltage and still outputs AC. By contrast, a typical switching power adapter comprises several key modules: rectification, filtering, PWM control, voltage transformation, rectification, sampling, and additional filtering. Of course, numerous smaller components are also integrated into the design. Now that you’re familiar with the basic classification of power adapters, let’s take a closer look at their internal structure.
Power adapters used in electronic devices primarily serve to convert input voltage into various output levels, thereby supporting the proper operation of different circuits; they provide electrical isolation between circuit sections operating at different potentials; they present high impedance to alternating current while offering low impedance to direct current; and they maintain or shape waveform characteristics and frequency response across differing potential levels.
1. The switching transformer is one of the core components in a switch-mode power supply.
2. A temperature probe is used to monitor the internal temperature of the power adapter. When the temperature exceeds a preset threshold—slightly varying among different brands—the protection circuitry will shut off the adapter’s voltage output, thereby preventing damage to the adapter.
3. Fuse, rated at 2.5 A/250 V; when the current in the circuit exceeds the limit, the fuse will blow to protect other components.
4. The rectifier bridge, rated D3SB, converts 220 V AC into DC.
5. Operational amplifier ICs (integrated circuits) are essential components for protection circuits and voltage regulation.
6. An inductor coil (also known as a choke) primarily serves to reduce electromagnetic interference.
7. Filter capacitor, rated at 180 μF/400 V, serves to eliminate AC ripple from the DC supply, ensuring more reliable circuit operation.
8. High-power switching transistors are among the core components of switch-mode power supplies; their indispensable role enables these supplies to operate in a “on-off” manner.
9. A varistor functions by rapidly reducing its resistance when the external voltage exceeds a certain threshold, causing the fuse connected in series with it to blow and thereby protecting the rest of the circuit from damage.
10. The secondary rectifier diode functions to convert low-voltage AC into low-voltage DC. In IBM power adapters, the rectifier diodes are often configured as two high-power units operating in parallel to achieve a higher current output.