How to design a switching power supply 5, how to design a switching power supply

Turn on the AC input power.

Resets the module.

Output Overcurrent: The overcurrent characteristics are shown in Figure 1 as the given values in the tableWhen the current is overcurrent, the constant current reaches 60 voltage, and then the current-voltage transition drops. (Finally the residual with the short circuit.)

same state).

Reverse output: When the input is reversed, a fuse is blown out (32A 55V) in the external circuit

Overheating: The internal detector prohibits the module from operating in overheating, and automatically resets once the temperature is reduced below normal values.

Display and indication functions.

Input Monitoring: Input grid is displayed normally.

Output Monitoring: The output voltage is displayed normally. (Shutdown in case of overvoltage).

Current Limit Indicator: The current limit working status is displayed.

Load Indication: Load greater than low limit current display.

Relay: Inputs and outputs and inputs are displayed normally at the same time.

Output current monitoring: load from 10 to 100, indication accuracy of 5

Remote Control Lower: Provide a remote control adjustment window.

System features. Voltage trimming: In order to adapt to the temperature characteristics of the battery, the output voltage of the module can be temperature compensated.

Load dropping: In order to meet the requirements of parallel current sharing, the external characteristics should be adjusted. The typical voltage drops so that the load goes from zero to an increase of 100 at the output voltage.

250mV

Remote shutdown: remote shutdown can be realized.

Electrical insulation. The following tests are 100 tests on the completed product.

1.Between L (grid) and N (center line) and other terminals, the test DC voltage is 6kV

2.Test DC between all outputs and l,n and ground, which checks the insulation between the output and ground.

3.The following points are tested to all other terminals DC 100V:

Voltage drop (11 and 12 pins).

Relay contacts (14, 15 and 16 pins).

Give me your email address and send you a material for reference.

Buy a few books to see, first master several commonly used circuit topologies, especially flyback, it is recommended to buy "Switching Power Supply Design (Third Edition)" and "Switching Power Supply Design and Optimization" and other switching power supply books, read more books, do more to make a simple small switching power supply slowly get started.

First choose a circuit scheme and understand the principle. Then draw a scoop according to the gourd.

Modify the parameters appropriately according to your own requirements.

Efficiency, power factor, input and output voltage, ripple, etc.

First understand the most basic topology, imitate it in the software, and then decide which direction to do and continue to go deeper.

The switching power supply is mainly composed of three parts: PWM control module, switch tube (BJT, MOSFET, IGBT, etc.) and filter (inductance, capacitance), and the isolation switching power supply also includes an isolation transformer. Of course, it is also necessary to consider the design of EMI, PFC, i.e. Power Factor Correction).

There are still some linear power supplies in low-power power supplies, but in medium and high-power power supplies, linear power supplies have been replaced by switching power supplies. With the increase of the frequency and function of the control chip, the development of high-speed and low-power power switch is successful, and the switching power supply is the main development direction of the future power supply.

How to use the switching power supply - how to use the switching power supply.

With the popularization of electrical equipment, switching power supply is widely used in our daily life, and it is an indispensable power supply method. Below, I will share with you how to use the switching power supply, I hope it will be helpful to you!

Wiring method

L: Connect to 220V AC live wire.

N: Connect the 220V AC neutral line and shout away.

FG: Ground connection.

g: DC output. Earth.

5V: The port that outputs the +5V point.

ADJ: It is to adjust the output voltage within a certain range, the rated voltage output on the switching power supply is fixed at the factory, that is, the nominal rated output voltage, setting this potentiometer allows the user to adjust the output voltage in a small range according to the actual use, and generally does not need to adjust it.

Output calculations

Due to the high efficiency of the switching power supply, it can generally reach more than 80%, so in the selection of its output current, the maximum absorbed current of the electrical equipment should be accurately measured or calculated, so that the selected switching power supply has a high performance ratio, and the output calculation formula is usually as follows:

is=kif

Where: is - the rated output current of the switching power supply;

if—the maximum absorbed current of the electrical equipment;

k—margin coefficient, generally taken;

Grounding

Switching power supply will produce more interference than linear power supply, electrical equipment sensitive to common mode interference, should be clear and take grounding and shielding measures, according to ICE1000, EN61000, FCC and other EMC restrictions, switching power supply are to take EMC EMC measures, so switching power supply should generally be equipped with EMC electromagnetic compatibility filter.

For example, the HA series switching power supply of LeadHuafu Technology can connect its FG terminal to the ground or to the user's chassis to meet the above-mentioned electromagnetic compatibility requirements.

Protection circuits

The switching power supply must have protection functions such as overcurrent, overheating, and short circuit in the design, so the switching power supply module with complete protection functions should be preferred in the design, and the technical parameters of the protection circuit should match the working characteristics of the electrical equipment to avoid damage to the electrical equipment or the switching power supply.

Power switches are very common in our daily life, there are many types of power switches, we should pay attention to aesthetics and practicality when installing, and more attention is paid to the safety of power switches. You know, there are many power switches around us, each of which will be connected to the power supply, if the quality is not up to it, it will be a big problem for our own safety and the safety of our families. So how many types of power switches are there on the market?

How to install the power switch in our home? Let me tell you.

How many types of power switches are there?

There are many switches involved in the family, and power switches can be classified according to their structural characteristics, number of poles, number of positions, use, etc.

1.Classified according to structural characteristics. According to the structural characteristics, power switches can be divided into button switches, toggle switches, membrane switches, mercury switches, lever switches, micro switches, travel switches, etc.

2.Classified by the number of poles and digits. According to the number of poles and positions, the power switch can be divided into single-pole unit switch, double-pole double-position switch, single-pole multi-position switch, multi-pole unit switch and multi-pole multi-cherry position switch.

3.Categorized by use. Power switches can be divided into power switches, recording and playback switches, band switches, pre-selection switches, limit switches, foot switches, transfer switches, control switches, etc.

How to install the power switch

1.Determine the location of the power switch installation (the exposed socket should generally not be less than one meter from the ground, and the concealed socket should not be less than one meter from the ground) (this article takes the concealed three-hole socket as an example).

2.It is necessary to draw the frame of the outer box of the socket for installation, and then dig a pit according to the drawn frame line, and the depth is equivalent to the thickness of the socket.

3.Fix the plastic plate at the bottom of the dug pit, thread the three unstripped wires through the mounting box, and then fix the installation box.

4.First peel off the zero wire (generally blue) head and connect with the socket terminal, then strip the ** type differential wire (generally red) head and connect with the socket terminal base (the general socket live wire and the neutral wire terminal block are symmetrically designed), and finally peel off the ground wire head (generally yellow) and connect with the socket ground wire terminal.

5.Place the power switch carefully in the mounting box and fix it, and the installation is complete.

Note: plastic plate, installation box, strength should be enough, flat, no deformation, there is a product certificate.

With the rapid development of the economy, we have higher requirements for the environment around us. For example, the power switch is one of them, and the electrical appliances corresponding to each switch are different, and some electrical appliances even have special power switches. So we must choose the right model when choosing a power switch.

Through the above article, we learned how many types of power switches there are and how to install them in our homes. The installation method is very simple, but generally we find a professional person to install it.

You can get it for free