The working principle is to realize the switching and adjustment of the power supply by controlling the conduction and cutoff of the switching tube. When the input voltage is converted into the required output voltage through the transformer or DC-DC converter, the switching power supply chip will control the on-time of the switching tube according to the change of the output voltage, so as to achieve stable regulation of the output voltage.
Switching power supply working principle Switching power supply control mode is divided into width modulation type and frequency modulation type two, in the actual application, width modulation type is used more, in the current development and use of switching power supply integrated circuit, the vast majority is also pulse width modulation type. Therefore, the following mainly introduces the adjustable width switching voltage regulator power supply.
Linear power chip: A linear power chip is a common type of power chip that works by converting the input voltage into a stable output voltage through an amplifying and regulating circuit. This type of power chip has the characteristics of simplicity and low cost, and is suitable for some pairs of power suppliesOccasions where quality requirements are not high.
The basic working principle of PWM switch current stabilization is that in the case of input voltage, internal parameters and external load changes, the control circuit through the difference between the controlled signal and the reference signal closed-loop feedback, adjust the pulse width of the main circuit switching device, so that the output current of the switching power supply is stable (that is, the constant current power supply).
Oscillation circuit: the drain-source pole and R4 of the main winding NQ1 of the switching transformer are the path of the working current of the power supply; R1 provides the starting current; The self-feeding winding NDC1 forms the supply voltage of the oscillator chip. These three linksNormal operation is a prerequisite for the power supply to be able to oscillate.
or the pressure strip is not pressed, 3843 series of power supply as long as the switch tube is blown up, will lead to UC3843 and safety tube burned, in addition, you should pay attention to check the input rectifier bridge or rectifier diode is partially damaged. The damage you said after 1 minute of work should generally be the problem of poor heat dissipation of the switch tube.
<16, LT3763, etc., you log in to their website, and then find the power controller in the buck type, the above list has voltage, current, price and other parameters. Personally feel that the lm power supply is not very good to adjust, the ripple is large, easy to hiccup.Power management chip model table is as follows: PIC24F32KA301. PIC24F16KA301. PIC24F16KA101. PIC18F14K22. PIC18F14K50. PIC16F1829. PIC16F1509. dsPIC33FJ12MC201. PIC24F08KA101. Power Management ics (PMIC) play a crucial role in modern electronic devices, monitoring, controlling and regulating the power supply to ensure stable operation of the device under a variety of operating conditions.
If the current is only about 200MA, you can use LM7805. LM7805 is a linear power supply IC (the limit input voltage is 36V), the main problem is that the loss is relatively large when 24V to 5V, the heat is relatively serious, can be addedHeat sink, simple peripheral circuit.
Rainproof switching power supply is also so complicated, what is it used for? The general 494 power supply does not need the optical coupling, this power supply is a bit like the computer power supply. The IC burned is estimated to be an auxiliary power chip, such a chip too much, difficult to judge, the IC around the back of the two sides of the figure put up to see.
UC2843, also known as current driven pulse width modulation chip, is a single-ended output control circuit coreThe biggest advantage is that the external components are very few, the wiring is relatively simple, the reliability is high, and the cost is low. It can be isolated from the power grid through the high-frequency transformer, and is suitable for the switching power supply below 100W.
General DC-DC can be, but PWM generation needs to be output from the main chip, overcurrent protection and overheat protection are integrated inside the chip. Such as LM3670 or some backlight chips such as CP2123 and so on.
PWM switching power controller adopts FAN7556 chip; The buck type single-chip AC-DC converter uses HV-2405E chip;High power thick film power supply switching power Converter STR-F6654 chip Switching power supply chip selection consideration first: performance. We have selected the IC to be used in the product, and the product is to be certified.
The control circuit is the circuit used to control the switching tube on and off in the switching power supply, and its design needs to consider the switching speed, stability and other factors. The commonly used control circuits are PWM control circuit based on 555 timer and digital control circuit based on single chip microcomputer.
The main power management chips are dual in-line chips, and some are surface mount packages, whichHIP630x series chip is a classic power management chip, designed by the famous chip design company Intersil.
TI UCC12050: This is oneHigh performance, low cost current mode PWM controller for offline and DC-DC converter applications. Its features include adjustable frequency, cycle by cycle current limitation, etc. TI UCC28950: This is a chip for high performance, low standby power offline switching power supply.
The chip models are TPS6108SGM4151 and so on. The TPS61085 is a high efficiency boost converter with input voltage range of 5V to 12V, output voltage range of 8V to 15V, maximum output current of 2A, with low power consumption, high efficiency and stable output characteristicsSex.
, LM7805, etc. 7-pin power chip Model 8370 is a commonly used power management chip, mainly used for power supply management of electronic equipment. With over voltage, under voltage, over current, short circuit protection and other functions, support a wide range of input voltage.
Pin power management chip models include PF7001S PF7001 SOP, UC3843D UC3843AD SOP1LTC4263IS#PBF Linear Technology.
Pin power management chip models there are many, the followingIs some common models: AP2141:14 pin power management chip, with overvoltage protection, overcurrent protection and short circuit protection functions. TPS2113A: Dual channel 14-pin power management chip for applications such as battery switching, power selection, and power management.
1, switching power supply chip. The 5Q1265RT is a single-row dual-row TO-220F-5L5 pin package with an operating voltage of 650V, pulse current of 48A, and power consumption of 135W, operating frequency 18-22KHz characteristic switching power supply chip.
2, KA5Q1265RF is a new type of power supply thick film circuit produced by Fairchild, it is composed of power control chip and high-power field effect tube, high integration, and KA5Q1265RF only 5 pins, it and less peripheral components can constitute excellent performance, simple circuit switching power supply.
3, What question you want to say ah! This five-pin single-ended switching power supply chip, 1 pin connected to the switching power transformer, two-pin grounding, three-pin supply voltage, four-pin voltage regulator feedback, five-pin synchronous controlMake.
4, foot 300 volts (MOSFET drain); 2 feet (ground) 0 volts; 3-pin integrated block power supply pin 21 V; 4 pin feedback control input/overcurrent protection 0.9 volts; 5 pin synchronous motion control 4 volts.