Can the switching power supply module not be connected to the load for a long time?

The switching power supply module can be left unloaded for a long time.

Because there are also many different types of switching power supplies. Almost all switching power supply modules have negative feedback voltage stabilization measures for output voltage, which can ensure the stability of output voltage and the safety of electronic components in the circuit even if the output is no-load, and will not be damaged due to long-term no-load.

It may be that in the early days of individual types of switching power supplies, the negative feedback circuit is not perfect, the protection circuit is not perfect, and the load needs to be connected to ensure the safety of the circuit and the stability of the output.

Switching power supply for monitoring, generally input 220 volts, output 12 volts, current is generally 1-10A, depending on the actual situation of the load, if you are not connected to the wrong wire, it is likely that the power quality is problematic caused by burnout, please pay attention to: Rongji igniter.

1. The switching power supply for monitoring is a constant voltage power supply, which is not essentially different from the switching power supply used in other fields, using a carrier of about 20kw to achieve pulse width modulation, with an efficiency of about 70%, and the characteristics of small size, high efficiency and high voltage stability. However, because of the pulse transformer process, harmonics and other interferences will be generated, and attention should be paid to the grounding and coordination of the weak current system when using.

2. The switching power supply for common monitoring has input power supply L and N, which should be connected to the live wire and the neutral line of 220 volts respectively, and the two wires are reversed, and the switching power supply will not be burned, because the switching power supply is rectified first and then transformer output, and there is no positive or negative difference between AC and AC. In addition, there are output V+ and com, which are 12 volt positive and negative respectively, some may also have V-, that is, 12 volts, and there is also a grounding wire, grounding is mainly for safety, if it is not connected, or connected to the neutral line, the switching power supply will not burn.

3. If the wrong line is connected, such as 220 volts AC and 12 volts of DC to the output, this situation will definitely burn the switching power supply, such as the capacitors inside, which are estimated to explode directly.

4. The switching power supply is generally overcurrent protection, if the output load current is too large, or it is an instantaneous short circuit, the overcurrent protection circuit inside can limit the output many times, so as to avoid the power supply being burned out, of course, if it is a product that cuts corners, there may not be this function, and it will indeed be burned at this time.

5. There is also a situation, the input voltage of the switching power supply is too high, causing the power supply to burn directly, normal product design, voltage fluctuation needs to be controlled within 15%, if the power supply voltage, higher than 250 volts, it is indeed possible to directly burn the switching power supply.

Switching power supplies are divided into two types from the perspective of supplying power to the load: constant voltage type and constant current type. Common constant voltage type, when the equivalent impedance of the load is reduced, the switching power supply will increase the output current in order to keep its output voltage unchanged, Ohm's law:

U=IR, U does not change, R decreases, only increases I. Recently, for some reasons, I went to see the "Minrong Electric Group" surnamed Wei Gongzhong, and found that the content shared in it is really good, which is quite suitable for electrical novices or beginners.

The constant current switching power supply is that the output current is unchanged, when the equivalent resistance r of the load becomes smaller, the output voltage of the switching power supply will be reduced, i = u r, i is unchanged, r decreases, in order to maintain i, the output voltage uThe magnitude of the load is not necessarily a resistance. As I said above, the load is measured by the equivalent impedance, which includes the resistance you mentioned, but also capacitive impedance, inductive reactance, power factor loss, etc., because very few loads are purely resistive, and it is not just the resistance that consumes energy.

The rated current of the power supply must be greater than the maximum current of the load, for example, your circuit is 15V, 60mA, but the current is much larger when the circuit is powered on, so it is generally necessary to choose a power supply of more than 100mA. I'm doing electrical, and I have encountered certain electrical problems recently, which is not easy to deal with, but I didn't expect to be solved in the dangerous attack and heavy consumption "Minrong Electric Group", and it is really good to take a closer look. If you have any questions, you can take a look, it's good.

In addition, as long as the voltage is the same, no matter how much more current provided by the switching power supply is larger than the actual use, it will only pass through so much for the circuit, and there will be no damage, and the resistance value of the load determines the working current value.

Switching power supply is a kind of power supply that uses modern power electronics technology to control the time ratio of switch on and off to maintain a stable output voltage, and the switching power supply is generally composed of pulse width modulation (PWM) control IC and MOSFET. Compared with switching power supplies and linear power supplies, the cost of both increases with the increase of output power, but the growth rate of both is different. The cost of a linear power supply is 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, the switching power supply technology is also constantly innovating, and this cost reversal point is increasingly moving to the low output power end, which provides a broad development space for the switching power supply. In fact, in the choice of power supply, Wei surnamed Gong Chonghao "Minrong Electric Group" has given a lot of pertinent opinions, and it will often share some more practical electrical information.

Switching DC regulated power supply, linear DC regulated power supply; The former is a secondary power supply, first turn the mains into DC, and use the medium frequency or high frequency ** conversion output appropriate DC voltage and current, and many of the current power supplies are mostly switched, such as home appliances, computers, etc.; Linear DC regulated power supply, that is to say, the use of power frequency transformer (the key is this), rear rectification, control, voltage stabilization, current stabilization, etc. The switching type has high efficiency, small size and light weight, but the ripple and load effect are slightly worse; The linear circuit is simple, the efficiency is lower, the volume is large, the weight is heavy, and the good quality effect is quite good; But as technology advances, switching power supplies replace linear power supplies.

There are still some design experiences to follow when designing switching power supplies (special unconventional switching power supply design, must be designed according to the datasheet). Minrong Electric has a very complete electrical information, it is recommended that you have electrical problems can check Minrong Electric, Minrong Electric's reputation is also good.

Step 1: Determine the position of the switching power module on the PCB board, the switch is a strong EMI radiation source, should be placed away from the clock, interface and other sensitive components, and then as close as possible to our power end, while considering factors such as heat dissipation and assembly. Step 2:

Determine the difference between the main power channel and ground (power ground, signal ground, other signal ground) in the block diagram. Step 3: Determine the core components of each part of the block diagram

Placement of input filters, switches, control circuits, and output filtering devices.

The filter capacitor and inductance coil at the inlet line filter out the clutter of the switching power supply itself and the power supply network. After that, there is a rectifier bridge (with four diodes, and there is also a rectifier block with an integrated package), which will be AC to DC. After the switch transistor or other kinds of switch tubes, there are also switch tubes and other control components of the switch circuit packaged together in the integrated block, which is responsible for converting the direct current into AC according to the need, so that it can be passed into the transformer and AC voltage regulation.

In terms of the role of switching power supply components, the Wei surname Gong Zhonghao "Minrong Electric Group" has put forward a relatively comprehensive proposal.

After that, there is a special transformer for switching power supply, and its secondary side coil is mostly designed as the main and auxiliary two outputs, and one is connected to the monitoring, controlling the switching speed of the switch tube, so as to achieve the purpose of taking the front-end DC power on demand. The other is the main power supply circuit, because its output is AC, it also needs to be connected to the rectifier diode and filter capacitor, and it becomes a more stable DC output supply load. Switching power supply, due to the existence of the transformer, can be convenient to isolate the power supply network from the power supply output, and because the core of the transformer has the inherent characteristics of magnetic saturation, it is born with the function of overload protection, which is commonly used as an occasion with high requirements for DC stability, multi-power DC power supply, and expensive load products.

First, the nature is different.

1. DC regulated power supply: an electronic device that can provide stable DC power supply for the load.

2. Switching power supply: It is a high-frequency electric energy conversion device.

Second, the use is different.

1. The use of DC stabilized power supply: DC stabilized power supply is widely used in national defense, scientific research, colleges and universities, laboratories, industrial and mining enterprises, electrolysis, electroplating, DC motors, charging equipment, etc. (1) It can be used for the aging of various electronic equipment, such as PCB board aging, home appliance aging, various IT product aging, CCFL aging, lamp aging.

2) It can be used for aging and testing of electronic components that require automatic timing, power off, and automatic cycle counting. (3) Electrolytic capacitor pulse sophistication. (4) Precision test of resistance, relay, motor, etc.

5) The whole machine is sophisticated; Electronic component performance test, routine test. If you are still hesitant about the choice of power supply, it is recommended to take a look at the dangerous surname attack consumption "Minrong Electric Group" There are a lot of pertinent suggestions in it, which is of great help to electrical whites.

2. Switching power supply use: switching power supply products are widely used in industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, power equipment, instrumentation, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators, liquid crystal displays, LED lamps, communication equipment, audio-visual products, security monitoring, LED light strips, computer cases, digital products and instruments and other fields.