How to choose a switching power supply
How to choose a switching power supply, switch and socket is an indispensable part of our home renovation, now more and more electrical appliances in life, the function is also a variety of different, in the structure and components have become complex. So how to choose the switching power supply?
How to choose a switching power supply 1
1, the material is very important
Generally speaking, the switch is made of plastic, that is, insulation, but also anti-leakage. However, we all know that plastic is flammable, so when you are selecting, you must choose the fire-retardant material!
2, the structure of the switching power supply can not be ignored
The bottom of the switching power supply have a bracket structure, to increase its pressure resistance. The bracket on the market generally has two kinds of steel frame and PC. PC material bracket is insulated, but the pressure resistance is not as good as the steel frame. Therefore, nowadays, there are two layers of bracket structure, and three layers, the combination of steel frame and PC use.
3, steel frame and copper
Good switch socket, copper for high-precision phosphor bronze molding, smooth and shiny surface, conductive heat dissipation performance, flexible and not easy to deform. Inferior copper parts, copper sheet thin, rough surface, dull color, copper content is relatively low, and some are even iron, easy to danger.
4, the details more reflect the success or failure
Good socket jacks are tighter, not easy to insert, you need to shake in order to insert. This is a child lock set above the socket to enhance protection from the risk of electrocution, especially if there are children in the house.
5, switch contacts
When we press the switch, we can hear the sound, which is generated by the contacts, is the sound produced by the two metal pieces or metal balls.
If the contacts are not safe enough, it is easy to generate an arc, causing the switch short-circuit, the occurrence of critical limits, a good switch are generally used silver-cadmium contacts, can play a momentary overcurrent function, the ability to inhibit the arc is very strong.
The poor quality of the switch, the use of copper or tin silver-plated contacts, cutting corners, there is a high risk of safety. Be sure to pay attention to this detail when selecting.
Switching power supply for everyone is very heavy, but also very prone to problems. Ring.
We, as an ordinary consumer, may be for the switching power supply is not yet understood, in the face of a large number of brands, we do not know how to choose, through my above to you, I believe that you see will have an understanding, I hope to be able to help you.
Switching power supply how to choose 2Switching power supply
A, the main purpose: switching power supply products are widely used in industrial automation control, military equipment, scientific research equipment, LED lighting, industrial control equipment, communication equipment, electric power equipment, instrumentation, medical equipment, semiconductor refrigeration and heating, air purifiers, electronic refrigerators. LCD monitors, LED lamps, communication equipment, audio-visual products and other electrical products.
Second, the type of power switch: there are two types of modern switching power supply: one is a DC switching power supply; the other is an AC switching power supply.
Third, the basic composition of the power switch: the main circuit, the control circuit, the detection circuit, the auxiliary power supply is composed of four aspects.
The price of switching power supply
One, Ming Wei switching power supply DR-120-24 120W 24V5A industrial-grade rail-mounted power supply package price of about 75 dollars.
Second, DC Meanwell switching power supply SE-500W600W transformer 220 to 12V50A24V20A36V48V10A price of about 160 dollars.
Third, Meanwell 800W high-power switching power supply S-800-24V/12V/27V/36V/48V/LED switching power supply price of about 226 dollars.
The above is the basic definition of the switching power supply and power switch price knowledge, I hope to provide you with some small help. In terms of power switch, with the development and innovation of power electronics technology, so that the switching power supply technology is also constantly innovating, the future of the power switch will be more and more intelligent.
How to choose a switching power supply 3
Sometimes home appliances will always be disobedient, out of the question, either the switch is not flexible, do not listen to the call, or which which suddenly leaked, but also really annoying, because the master and too much fuss, do not invite themselves and will not, do not worry, today I will tell you about the switching power supply accidents how to repair the method.
1, there is an output voltage, but the output voltage is too high
This fault generally comes from the voltage regulator sampling and voltage regulator control circuit. In the DC output, sampling resistors, error sampling amplifiers such as TL431, optocoupler, power control chip and other circuits *** with the composition of a closed control loop, any one of the problems will lead to higher output voltage.
2, no output, the fuse is normal, this phenomenon suggests that the switching power supply is not working or entered the protection state. First of all, to measure the power control chip start foot whether the start voltage,
If no start voltage or start voltage is too low, it is necessary to check the start resistor and start the foot of the external components of the leakage, at this time, such as the power control chip is normal,
then by the above checks can be easy to sell the industrial control in order to quickly find the fault. If there is a startup voltage, then measure the output of the control chip in the boot moment whether there is a high, low level jump,
If there is no jump, it means that the control chip is bad, the peripheral oscillator circuit components or protection circuit has a problem, you can replace the control chip, and then check the peripheral components; if there is a jump, the general switching tube is bad or damaged.
3, insurance burn or fried, mainly check the 300V on the large filter capacitors, rectifier bridge diodes and switching tubes and other parts of the anti-interference circuit problems can also lead to insurance burn, black.
It should be noted that: due to the switching tube breakdown caused by the insurance burn will generally be the current detection resistor and power control chip burned. Negative temperature coefficient thermistor is also easy to be burned with the insurance.
4, the output voltage is too low, in addition to the voltage regulator control circuit will cause the output voltage is low, there are a number of reasons below will also cause the output voltage is low:
a. The switching power supply load has a short-circuit fault (especially DC/DC converter short circuit or poor performance, etc.), at this time, should be disconnected from all the load of the switching power supply circuit,
in order to distinguish between switching power supply circuit or load circuit failure. If you disconnect the load circuit voltage output is normal, that is, the load is too heavy; or still not normal that the switching power supply circuit is faulty. b. Output voltage rectifier diode, filter capacitor failure, etc., can be replaced by the method of judgment.
c. The performance of the switching tube is degraded, which inevitably leads to the switching tube can not be normal conduction, so that the internal resistance of the power supply increases, and the ability to carry load decreases.
d. Poor switching transformer, not only cause the output voltage drop, but also cause the switching tube excitation is not enough so that the repeated loss of the switch.
e. Poor 300V filter capacitors, resulting in poor power supply with load capacity, the output voltage will drop once the load is connected.
E.