FAQ

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Q

What is a switching power supply in FA1029?


A

Switching power supply is a type of power supply that utilizes modern power electronics technology to control the time ratio of switch on and off, and maintain a stable output voltage. Switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET. Compared to linear power supplies, the cost of both increases with the increase of output power, but their growth rates vary. The cost of a linear power supply is actually higher than that of a switching power supply at a certain output power point, which is called the cost reversal point. With the development and innovation of power electronics technology, switching power supply technology is also constantly innovating, and this cost reversal point is increasingly moving towards the low output power end, providing broad development space for switching power supply.

Q

What are the drawbacks of FA1028's linear power supply technology today?


A

The linear power supply, known as the "energy vampire" due to its energy consumption characteristics, uses outdated technology from the early 19th century that is no longer compatible with current innovation. Linear transformers require the use of large iron cores and a large number of turns of copper wire to convert the conventional 50/60 cycle household AC voltage into a safer low voltage for our household appliances and electronic devices. As a result, their volume becomes exceptionally large, often occupying the position of two sockets on a wall outlet board or patch panel. Moreover, linear power supplies do not have intelligent components, making it impossible to identify whether the device is in standby or sleep mode, thereby preventing loss reduction. As a result, the power they consume far exceeds the actual required watts. You can test it by touching one of the large volume linear power supplies plugged into the wall socket. It feels very hot... this is just wasted power!

Q

What are the advantages of FA1027 switching power supply?


A

The second generation power supply, also known as switch power supply or simply "switch", appeared in the late 1960s. Engineers have found that they can reduce the volume and weight of transformers by increasing the AC frequency from 50 or 60 cycles per second to thousands of cycles per second, and significantly improve the efficiency of transformers (reducing energy waste in the form of heat dissipation)

Q

What is the basic working principle of FA1026 power supply?


A

The working process of a switching power supply is quite easy to understand. In a linear power supply, the power transistor operates in linear mode. Unlike a linear power supply, a PWM switching power supply allows the power transistor to operate in both on and off states, The volt ampere product added to the power transistor is very small (during conduction, the voltage is low and the current is high; during shutdown, the voltage is high and the current is low)/The volt ampere product on the power device is the loss generated on the power semiconductor device.

Compared with linear power sources, the more effective working process of PWM switching power sources is achieved through "chopping", which chops the input DC voltage into a pulse voltage with an amplitude equal to the input voltage amplitude. The duty cycle of the pulse is adjusted by the controller of the switching power supply. Once the input voltage is chopped into an AC square wave, its amplitude can be increased or decreased through a transformer. By increasing the number of secondary windings in the transformer, the number of output voltage groups can be increased. Finally, these AC waveforms are rectified and filtered to obtain a DC output voltage.

The main purpose of the controller is to maintain stable output voltage, and its working process is similar to that of a linear controller. That is to say, the functional block, voltage reference, and error amplifier of the controller can be designed to be the same as the linear regulator. Their difference lies in that the output of the error amplifier (error voltage) needs to pass through a voltage/pulse width conversion unit before driving the power transistor.

There are two main working modes of switching power supply: forward conversion and boost conversion. Although the layout differences between their respective parts are small, the working processes vary greatly and each has its own advantages in specific application scenarios.

Q

What is the workflow of FA1025 power supply?


A

After the mains power enters the power supply, high-frequency noise and interference signals are first removed through choke coils and capacitor filtering, and then rectified and filtered to obtain high-voltage direct current. Then, the DC power is converted into high-frequency pulsating DC power through a switching circuit, and then the high-frequency switching transformer is sent for voltage reduction. Then filter out the high-frequency AC part, so that the final output is relatively pure low-voltage direct current for computer use.

Q

What is the principle of the FA1024 switch circuit?


A

The principle of the off circuit is to form an oscillation circuit consisting of a switch tube and a PWM (Pulse Width Modulation) control chip, generating high-frequency pulses. Convert the high-voltage DC generated by the high-voltage rectification and filtering circuit into high-frequency pulse DC, send it to the main transformer for voltage reduction, and convert it into low-frequency pulse DC.

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