News

Home  -  News  -  Industry News

Power adapter cycle current control principle

source:Industry News Popular:adapter release time:2021-07-02 10:42:10 Article author:sznbone

  When the power adapter UC3842 chip is working normally, it is only controlled by the output of the error amplifier and the current detection feedback signal. When the timing capacitor of the oscillator is in the charging state, the oscillator outputs a low potential, which does not control the OR gate. At this time or The output state of the gate depends only on the output of the PWM latch. The output of the PwM latch is compared with the output voltage of the error amplifier and the current feedback voltage through the current comparator and sent to the R terminal of the PwM latch. In this way, the current The output of the detection comparator determines the output state of the UC3842. When the current feedback voltage is lower than the voltage of the error amplifier to the inverting terminal of the current comparator, the current detection comparator outputs a low potential, and the UC3842 outputs a high potential to drive the switch tube to turn on. This indicates The energy transmitted by the converter is not enough, and the transmitted energy must be increased through the conduction of the switch tube; first, when the current feedback voltage is higher than the voltage of the error amplifier to the inverting terminal of the current comparator, the current detection comparator outputs a high potential , UC3842 outputs a high potential to drive the switching tube to turn off. This indicates that the energy transmitted by the converter has reached the requirement in this switching cycle, and there is no need to increase the transmitted energy.

Power adapter cycle current control principle(图1)

  When the error amplifier outputs the highest voltage, the inverting input of the current detection comparator is the highest voltage, which is clamped at 1V. When the current feedback voltage reaches and starts to be greater than 1V, the output of the current detection comparator changes from low voltage to high voltage. Force the UC3842 to output a low potential and turn off the switching tube. In this way, the maximum current of the converter is limited, that is, the maximum input current limit. No matter the output of the converter is working normally or "overcurrent" or short circuit, the current flowing through the switching tube is limited in:


Read recommendations:

Dc Power Supply 12v 2A 5V 20A switching power supply pcb design

7W Open Frame Power Supply

12W European standard Adapter

Application of optocoupler in switching power supply

Classification of power adapter DC head.indian adapter

Previous:Design of Side Regulated Flyback Power Adapter Back to list Next:How to prevent noise from power adapter

The latest article

Related Products

The latest article

What are the types of mobile phone chargers and their functions?

2022-05-21

Advantages of switching power adapters

2022-05-21

Five core functions that the power adapter can achieve.adapter manufacture

2022-05-20

Analysis of the importance of power adapters for notebooks.adapter Processor

2022-05-20

Details of switching power supply in maintenance

2022-05-19

Understand the precautions of the power adapter and be an expert in electricity safety

2022-05-19

This is how the EMC interference of the switching power supply is generated.adapter wholesaler

2022-05-18

The relationship between the nominal voltage and current of the power adapter.power adapter price

2022-05-18

Five basic functions of notebook power adapters.adapter wholesaler

2022-05-17

Lightning surge immunity test method.power adapter price

2022-05-17

Switching power supply ripple source and control

2022-05-16

Level 6 energy efficiency standard power adapter T series

2022-05-16

Children sleeping with pacifiers are prone to tooth decay

2022-05-16

Six methods to deal with the heating problem of switching power supply transformer

2022-05-14

The principle of flyback switching power supply

2022-05-14

Types of thermal protection for power adapters.adjustable power adapter

2022-05-13

Summary of common faults of LED switching power supply

2022-05-13

The power transistor should be used like this in the power adapter

2022-05-12

4 modulation methods of switching power supply

2022-05-12

Some little knowledge about switching power supply

2022-05-11

Laptop Power Adapter Troubleshooting Steps

2022-05-11

9 classification methods of switching power supply

2022-05-10

Advantages and disadvantages of switching power supply current mode

2022-05-10

Advantages and disadvantages of switching power supply current mode

2022-05-09

9 classification methods of switching power supply

2022-05-09

Characteristics and working methods of PFC regulated switching power supply

2022-05-07

Six maintenance rules for drone lithium batteries.manual charger power adapter

2022-05-07

Reasons for Inrush Current in Switching Power Supply Design.adjustable power adapter

2022-05-06

The optimal solution of drone power management solution!12w acdc power adapter

2022-05-06

Characteristics of Switching Power Adapter Transient Loads

2022-05-05