**First, the Introduction of Switching Power Supply**
Switching power supplies are advanced power solutions that utilize modern power electronics to regulate the on and off time of a switch, ensuring a stable output voltage. These power supplies typically consist of a Pulse Width Modulation (PWM) control IC and a MOSFET. With continuous advancements in power electronics, switching power supply technology has evolved significantly. Today, they are widely used across various electronic devices due to their compact size, lightweight design, and high efficiency. As a result, they have become essential in supporting the rapid growth of the electronics and information industries.
**Second, the Basic Composition of a Switching Power Supply**
A typical switching power supply is composed of four main components: the main circuit, the control circuit, the detection circuit, and the auxiliary power supply. Each part plays a crucial role in ensuring the system operates efficiently and safely.
**1. The Main Circuit**
The main circuit is responsible for handling the input power and converting it into a usable form. It includes several key functions:
- **Inrush Current Limiting**: This prevents excessive current from entering the power supply during startup, protecting the internal components.
- **Input Filter**: It filters out noise from the grid and prevents internal noise from affecting the power source.
- **Rectification and Filtering**: Converts the AC input from the grid into a smooth DC voltage.
- **Inverter**: Converts the DC voltage into high-frequency AC, which is essential for efficient power conversion.
- **Output Rectification and Filtering**: Ensures the final output is a stable and reliable DC voltage suitable for the connected load.
**2. The Control Circuit**
The control circuit monitors the output voltage and compares it with a reference value. Based on this comparison, it adjusts the pulse width or frequency of the inverter to maintain a stable output. Additionally, it works with the detection circuit to implement various protection mechanisms, such as overvoltage, overcurrent, and thermal protection.
**3. The Detection Circuit**
This circuit continuously monitors key parameters like temperature, voltage, and current. It provides real-time data to the control circuit, enabling the system to respond quickly to any abnormal conditions.
**4. The Auxiliary Power Supply**
An auxiliary power supply provides the necessary power to start up the system remotely and to support the operation of the control and protection circuits, including critical chips like the PWM controller.
**Third, the Working Principle of a Switching Power Supply**
The core of a switching power supply lies in its ability to convert voltages efficiently using a pulse oscillator. This oscillator, made up of components like a switching transistor and a pulse transformer, generates pulsed electrical power. It converts the 300V DC input into the required output voltage through the secondary winding of the transformer. The basic electrical principle is illustrated in Figure 2.
**1. The Working Principle of the Pulse Oscillator**
The pulse oscillator begins when the power supply applies a forward bias to the base and emitter of transistor Q3 via resistors R10, R10A, and R15, causing Q3 to turn on.
As Q3 conducts, +Vc flows through the primary coil of the pulse transformer, then through the collector, emitter, and resistor R15 back to -Vc. During this time, an induced voltage is generated in the secondary coil. One end of the secondary coil connects to -Vc, while the other end connects to the base of Q3 via R12 and C8. The polarity of this induced voltage matches that of the self-inductance of the primary coil, increasing the base current of Q3 and driving it into saturation.
Once Q3 is saturated, the current no longer increases, and the waveform remains steady until t3. From t3 to t4, the polarity of the induced and self-induced voltages reverses, causing a reverse bias on Q3’s base through R12 and C8. This rapidly turns Q3 off, transitioning it from saturation to cutoff between t4 and t6.
After turning off, the absorption circuit consisting of D8, R17, and C7 quickly dissipates the reverse voltage and current generated in the primary coil, completing one oscillation cycle. This process repeats continuously, with the frequency determined by the inductance of C8 and the secondary coil.
The working mechanism of the pulse oscillator is shown in Figure 3.
Perkins Diesel Generator assembly by Perkins diesel engine, alternator, radiator, controller, base frame;
. World Famous diesel engine brand: Perkins
. World famous AC alternator brand: Stamford, Leroy Somer, Mecc Alte, Marathon, Faraday, SWT
. World famous genset controller brand: Deepsea, ComAp, Deif, SmartGen,
. Good Quality Cooling Radiator
. Start Battery system
Perkins Genset,Perkins Generator,Perkins Power Generator,Perkins Diesel Generator
Guangdong Superwatt Power Equipment Co., Ltd , https://www.swtgenset.com