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This article mainly talks about the summary of the basic knowledge of inverter, let's take a look together.

Summary of basic knowledge of inverter

  • Xindun
  • December 24, 2021

Q: What is a inverter and what does it do?

A: Generally, an inverter is an electronic device that converts a low-voltage (dc 12V/24V/48V) dc direct current into a 220-volt ac current. Because we usually use a 220-volt ac rectifier as a direct current, the inverter works the opposite way, that’s why it calls that name. We are in a "mobile" era, mobile office, mobile communication, mobile leisure and entertainment. In a state of movement, people not only need to be supplied by batteries or battery low voltage direct current (dc), at the same time more in need of our indispensable in the daily environment 220 v alternating current (ac), inverter can meet the demand of our this.


Q: What is "emotional load"?

Answer: Popularly say, use electromagnetism induction principle to make namely the high-power electric appliance product, if motor, compressor, relay, fluorescent lamp etc. Such products require a much larger starting current (about 3-7 times) at startup than is required to maintain normal operation. For example, a refrigerator that consumes about 150 watts of electricity during normal operation can have a starting power of more than 1,000 watts. In addition, due to the perceptual load, at the moment of switching power supply or disconnect the power supply will produce "potential voltage", this is far greater than the peak voltage inverter can withstand voltage, it is easy to cause the inverter instantaneous overload, affect the service life of the inverter. Therefore, this kind of electrical appliances to power supply waveform requirements are high.


Summary of basic knowledge of inverter


Q: What appliances can quasi-sine wave inverters be used for?

A: Quasi-sinusoidal waves are also divided into several types, from square waves that are similar to square waves to rounded trapezoidal waves that are closer to sine waves. We are only talking about square waves, which are the waveforms that most of the high frequency inverters currently on the market can provide. Such quasi sine wave inverter can be used in notebook computers, television sets, combined audio, video camera, digital camera, printer, all kinds of charger, PDA, game consoles, DVD, mobile DVD, household therapeutic apparatus, etc., the output power of the larger inverter can also be used in small electric appliances such as electric hair dryer, electric mug, kitchen appliances and so on. However, it is not suitable to use square wave inverter for long time for inductive load electrical appliances such as refrigerators and drills. Otherwise, it may damage the inverter and related electrical products or shorten the expected service life. If it is necessary to use inductive load, it is recommended to use pure sine wave inverter with large reserve power and super-large peak power inverter. Here, the pure sine wave inverter is used in television (traditional display). TV sets have the following three requirements for inverters: first, the demagnetization circuit has a great demand for electric energy in an instant when the TV is starting up, so the peak power of the inverter is very high. A 25-inch digital color TV, for example, USES about 80 watts of power at normal operating conditions, compared with 1,450 watts at the moment it starts up. Second, because the TV\'s field frequency is equal to the ac power grid frequency, the inverter must output ac power at an accurate frequency. Third, the inverter should not interfere with the television. Even can meet the above three conditions, the television when using quasi sinusoidal alternating current (ac), there will still be a few fixed picture interference lines, colour will be slight slant green (using old television, partial color more serious), but the other.


Q: What is the efficiency of a inverter?

A: The inverter itself consumes some power when it works, so its input power is greater than its output power. The efficiency of the inverter is the ratio of the input power to the output power of the inverter. If a inverter inputs 100 watts of direct current and 90 watts of ac, its efficiency is 90 percent.


Q: What is the continuous output power? What is peak output power?

Answer: Some use motor electrical appliances or tools, such as refrigerators, washing machines, electric drill, the current starting moment takes a lot to push, once started, it takes only a small current to maintain its normal operation. Therefore, for the inverter, there is the concept of continuous output power and peak output power. The continuous output power is the rated output power. The general peak output power is two times of the rated output power. It must be emphasized that the starting current of some electric appliances, such as air conditioners and refrigerators, is 3-7 times that of the normal working current. Therefore, only the inverter that can meet the peak starting power of the electric appliance can work normally.


Q:How to select inverter products?

A: The vehicle inverter is a power product that works in the environment of large current and high frequency. Its potential failure rate is quite high. Therefore, consumers must be cautious when buying. First, choose from the output waveform of the inverter, preferably not lower than the square wave. Secondly, the inverter should have complete circuit protection function. Third, the manufacturer should have good after - sales service commitment; Fourth, circuits and products have been tested for some time.


Q: Difference between inverter and transformer:

A: Inverter, it must be something of an inverter device then call, he have a direct difference between transformer, that is to say, he can realize dc input, output and communication, the working principle is like switching power supply, but the oscillation frequency within a certain range, such as if the frequency of 50 hz, the output of ac 50 hz. A inverter is a device that can change its frequency.

Transformer generally refers to a specific frequency equipment, such as power frequency transformer, is the transformer, we usually see their input and output must be within a certain range, such as 40 to 60 hz range can work.


Q: How should the inverter be connected to power and load?

Answer: Using the electric appliance below 150 watts can plug 150 watts inverter directly into the socket of cigarette lighter to use. More than 150 watts of inverters are connected directly to the battery via a crocodile clip wire, red to the positive pole of the battery, and black to the negative pole of the battery. If the power is located far from the battery, the principle of the inverter connection is: the connection between the inverter and the battery should be as short as possible, and the output line of 220 v ac should be as long as possible.


Q: How much power can the car cigarette lighter socket output?

Answer: take electricity from the cigarette lighter socket, the inverter should be able to drive more than 100 watts of power appliances. But some customers reported that after a few minutes of P4 laptop, the inverter would automatically cut off power and alarm. We know that the power consumption of the P4 laptop is about 90 watts, which is high. Due to some models from the battery to the cigarette lighter socket that electricity is not in conformity with the provisions for the use of wires and cigarette lighter socket, have increased in the circuit when the current is bigger loss, make the supply voltage of inverter fell sharply to the under-voltage protection circuit action point - 10 v, cause the inverter stop power supply. To solve this problem, and to ensure the normal, safe and reliable use of inverter, users are advised to keep the circuit wiring for copper core quality lines of the sectional area of 2.5 square millimeter above, and if necessary replace the cigarette lighter socket.


Q: Can an on-board inverter be used when the car engine is turned off?

A: yes. When using below 350 watts of small power electrical appliances, car battery can provide 30 to 60 minutes of power in commonly shut down engine. If only using a consumed 50-60 watts of notebook computer, it will last longer. Our standard sine wave inverter with under-voltage warning and under-voltage protection circuit, when use the battery for a long time led to the decrease of the voltage to 10 v, under-voltage protection circuit, the output voltage is cut off and call the police, in order to prevent the battery voltage is too low and cannot be started because the engine of the accident. Therefore, the user can safely use the inverter when the engine is closed.


Q: What if you want to use the inverter for a long time without starting the engine?

Answer: Another same voltage battery is connected with the positive and negative poles of the original battery respectively with a thick enough wire. In this way, the independent use time of the inverter can be greatly extended.


Q: What is the danger of using a inverter?

Answer: the conductor is carrying a very large current from the car battery to the inverter input, If the quality of the conductor is poor, the conductor is too thin or the load exceeds the standard, the copper wire will become hot or even fire, which will cause serious accidents. Therefore, in the use of the inverter, the operation must be strictly in accordance with the user manual.


Q: How do you know the inverter battery capacity?

A: the battery is printed with a lot of letters and Numbers. You can find the XXAH to see how large a battery it is. Let\'s start with the meaning of AH. A stands for amp, the unit of current, and H stands for hour. The two letters together mean "ampere hour", which is how much amperage current can be continuously output in an hour. The previous XX is usually two Numbers, namely the number of amps. For example, 45AH means that the battery can be output in an hour


Q: What type of battery do ordinary family cars use?

A: small cars with less than 1.3 liters are equipped with 40-45 amps, medium cars with 1.6 to 2.0 liters are equipped with 50-60 amps, and medium and large cars with 2.2 liters or more are equipped with 60-80 amps. The batteries for suvs and utility vehicles are generally larger than those for cars with engines of the same size. As to the voltage of battery, general use 12 v battery cars, use of diesel engines (including vehicles) most use 24 v battery, a few still use 12 v battery (e.g., iveco).


Q: How to equip the battery with the appropriate inverter?

A: if the battery is 12 volts at 50 amps, we multiply it by 12 volts at 50 amps, and the output power of the battery is 600 watts. If the inverter is 90% efficiency, then we multiply 90% by 600, and we get 540. This means that your battery can drive an inverter with a maximum output power of 540 watts. Of course, you can also take a "one-step" approach to purchasing an 800-watt inverter, regardless of the current size of the battery in your car. It is then used within the range permitted by the current battery and at full power when larger cars are replaced in the future. Finally, the power requirements for the inverter are not high, say 100 watts, so you can buy a small power inverter. In addition, in the power of the inverter, there is another important principle, namely when using inverter, not full load operation for a long time, otherwise it will shorten the life of inverter, the inverter failure rate will increase significantly. We strongly recommend the user to use the inverter at least 85% of the rated power.


Q: Why do we use the common multimeter to measure the AC output of the quasi sinusoidal inverter, and the voltage displayed is lower than 220 volts?

Question 16: why do you use the regular multimeter to measure the ac output of the pre-sine-wave inverter, and the voltage is over 220 volts?

A: this is normal, because when measuring ac voltage of quasi sine waves, a multimeter with a "true RMS" range should be used to get the correct reading.