1. Q: What is an inverter and what does it do?
A: Simply put, an inverter is an electronic device that converts low voltage (12 or 24 volts) direct current to 220 volts alternating current. Because we usually use 220 volt AC to be converted to DC, and the inverter has the opposite effect, hence the name. We are in a “mobile” era, mobile office, mobile communication, mobile leisure and entertainment. In the mobile state, people not only need low-voltage DC power supplied by batteries or batteries, but also need 220 VAC which is indispensable in our daily environment. The inverter can meet our needs.
2. Q: According to the output waveform, how many types of inverters are there?
A: There are two main types, one is a sine wave inverter and the other is a square wave inverter. The sine wave inverter outputs an even better sinusoidal alternating current than the grid we use today because it does not have electromagnetic pollution in the grid. The square wave inverter outputs a square wave alternating current of poor quality, and its positive maximum value to negative maximum value are generated at the same time, which causes severe instability effects on the load and the inverter itself. At the same time, its load capacity is poor, only 40-60% of the rated load, can not carry inductive load (see the following for a detailed explanation). If the load is too large, the third harmonic component contained in the square wave current will increase the capacitive current flowing into the load, and in severe cases will damage the load filter capacitor of the load. In view of the above shortcomings, in recent years, quasi-sine waves (or improved sine waves, modified sine waves, analog sine waves, etc.) have appeared, and the output waveform has a time from the positive maximum value to the negative maximum value. Interval, the effect is improved, but the waveform of the quasi-sine wave is still composed of polylines, which belongs to the square wave category and has poor continuity. In summary, sine wave inverters provide high quality AC power that can drive any kind of load, but with high technical requirements and cost. The quasi-sinusoidal inverter can meet most of our electricity demand, with high efficiency, low noise and moderate price, thus becoming the mainstream product in the market. The square wave inverter is made of a simple multi-vibrator. Its technology belongs to the level of the 1950s and will gradually withdraw from the market.
3. Q: What is “inductive load”?
A: In layman's terms, high-power electrical products such as electric motors, compressors, relays, fluorescent lamps, etc., which are manufactured using the principle of electromagnetic induction. This type of product requires a much larger starting current (approximately 3-7 times) than the current 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 1000 watts. In addition, since the inductive load is connected to the power supply or disconnected from the power supply, a back electromotive voltage is generated. The peak value of this voltage is much larger than the voltage that the inverter can withstand, which easily causes the inverter to be overloaded instantaneously. , affecting the life of the inverter. Therefore, such electrical appliances have higher requirements on the power supply waveform.
4. Q: Which electrical appliances can the quasi-sine wave inverter 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 only discuss square waves here, which is also the waveform that most commercially available high frequency inverters can provide. These quasi-sine wave inverters can be used in notebook computers, televisions, combination audio, video cameras, digital cameras, printers, various chargers, palm power, game consoles, DVD players, mobile DVDs, home therapy devices. And so on, the inverter with large output power can also be applied to small electric heating appliances such as hair dryers, electric cups, kitchen appliances and the like. However, it is not suitable for long-term use of quasi-sine wave inverters for inductive load electrical appliances such as refrigerators and electric drills. Otherwise, it may cause damage to the inverter and related electrical products or shorten the expected service life. If inductive loads must be used, it is recommended to use a quasi-sinusoidal inverter with a large reserve power, such as the oversized peak power inverter provided on this website. Here, focus on the example of a quasi-sine wave inverter applied to a television set (traditional display type). The TV has the following three requirements for the inverter: First, when the TV is turned on, the degaussing circuit has a great instantaneous demand for electric energy, so the peak power requirement of the inverter is very high. For example, a 25-inch digital color TV consumes about 80 watts of power during normal operation and up to 1,450 watts of power at startup. Second, because the field frequency of the TV set is equal to the AC grid frequency, the frequency at which the inverter outputs AC power must be accurate. Third, the inverter should not interfere with the TV set. Even if the above three conditions are met, when the TV uses quasi-sinusoidal AC power, there will still be several fixed interference patterns on the screen, and the color will be slightly greenish (the color cast is more serious when using the old TV), but The other is no different.
5. Q: What is the efficiency of the inverter?
A: The inverter itself consumes a part of the power when it is working. Therefore, its input power is greater than its output power. The efficiency of the inverter is the ratio of the input power of the inverter to the output power. If an inverter inputs 100 watts of direct current and outputs 90 watts of alternating current, then its efficiency is 90%.
6. Q: What is the continuous output power? What is the peak output power?
A: Some electrical appliances or tools that use electric motors, such as refrigerators, washing machines, electric drills, etc., require a large amount of current to drive at the moment of start-up. Once the start-up is successful, only a small current is needed to maintain its normal operation. Therefore, for the inverter, there is also 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 twice the rated output power. It must be emphasized that some electrical appliances, such as air conditioners and refrigerators, have a starting current equivalent to 3-7 times the normal operating current. Therefore, only the inverter that can meet the peak power of the appliance can work normally.
7. Q: How should I connect the inverter to the power supply and load?
A: Use 150 watts or less of electrical appliances to directly plug the 150 watt inverter plug into the cigarette lighter socket. The inverter of more than 150 watts is directly connected to the battery through the crocodile clip wire. The red wire is connected to the battery positive pole, and the black wire is connected to the battery negative pole (not reversed, remember!) If the power is far from the battery, the inverter is connected. The principle is: the connection of the inverter to the battery should be as short as possible, and the output line of the 220 volt AC is longer.
8. Q: How much power can the car cigarette lighter socket output?
A: From the cigarette lighter socket, the inverter should be able to drive electrical appliances with a power of more than one hundred watts. However, some customers have reported that after a few minutes of connecting the P4 laptop, the inverter will automatically power off and alarm. We know that the power consumption of the P4 laptop is about 90 watts, which is higher. Since some models use non-compliant wires and cigarette lighter sockets on the circuit from the battery to the cigarette lighter socket, the loss in the circuit increases sharply when the current is large, causing the voltage supplied to the inverter to drop sharply to The critical point of the undervoltage protection circuit action - 10 volts, causes the inverter to stop supplying power. In order to solve this problem and ensure the normal, safe and reliable use of the inverter in the future, it is recommended that the user replace the wires of the above circuit with a high-quality wire with a copper core cross-section of 2.5 square millimeters or more, and replace the cigarettes when necessary. Socket.
9. Q: Can I use the car inverter when I turn off the car engine?
A: Yes. When using a low-power appliance below 350 watts, a typical car battery can provide 30-60 minutes of power when the engine is turned off. If you only use a laptop that consumes 50-60 watts, the time will be longer. many. Our quasi-sine wave inverters are equipped with undervoltage warning and undervoltage protection circuits. When the battery is used for a long time and the voltage drops to 10 volts, the undervoltage protection circuit starts, the output voltage is cut off and an alarm is issued to prevent the battery from being An accident where the voltage is too low to start the engine. Therefore, the user can safely use the inverter with the engine off.
10. Q: What if I want to use the inverter for a long time without starting the engine?
Answer: Make another battery of the same voltage and connect the positive and negative poles with the thick and negative wires to the positive and negative poles of the original car battery. In this way, the independent use time of the inverter can be greatly extended.
11. Q: What is the danger of using an inverter?
A: The wire from the car battery to the input end of the inverter carries a very large current. If the wire is inferior, the wire is too thin or the load exceeds the standard, the copper wire will heat up or eventually ignite, which will cause a serious accident. Therefore, in the use of the inverter, it must be operated in strict accordance with the provisions of the user manual.
12. Q: How do I know the battery capacity?
A: There are many letters and numbers printed on the battery. Just find the word XXAH and you can know that this is a large capacity battery. Let me first say the meaning of AH, A stands for amperage (amp.), which is the unit of current, and H stands for hour. The two letters together mean "ampere hours", which is how many amps of current can be continuously output in an hour. The previous XX is usually two numbers, the number of amps. For example, 45AH means that the battery can output
(12 volts) 45 amps of current in one hour . As for the power that this battery can output, we multiply 12 volts by 45 amps to get 540 watts, which is the output power of the battery (theoretical value).
13. Q: What type of battery is used in a general family car?
A: Under normal circumstances, small cars with a cylinder volume of less than 1.3 liters are equipped with 40-45 ampere-hour batteries, 1.6-2.0 liters for medium-sized cars with 50-60 ampere-hours, and medium-sized and large cars of 2.2 liters or more. It is equipped with a 60-80 ampere battery. Off-road vehicles and utility vehicles are generally equipped with larger batteries than cars of the same size. As for the voltage of the battery, the car uses a 12-volt battery. The car with a diesel engine (including the truck) mostly uses a 24-volt battery, and a few still use a 12-volt battery (such as Iveco).
14. Q: How do I equip my battery with a suitable inverter?
A: If the battery specification is 12 volts 50 amps, we use 12 volts multiplied by 50 amps to get a battery output of 600 watts. If the efficiency of the inverter is 90%, then we use 90% multiplied by 600 watts to get 540 watts. This means that your battery can drive an inverter with an output of up to 540 watts. Of course, you can also take a "one-stop" approach to purchasing, that is, to buy an inverter with an output of 800 watts regardless of the specifications of the battery used in your car. Then, use it within the allowable range of the battery at the moment, and then use a larger car in the future and then use it at full power. Finally, the power requirements of the inverter are not high, for example, 100 watts is enough, then you can buy a small power inverter. In addition, when determining the power of the inverter, there is also an important principle that when using the inverter, do not operate at full load for a long time, otherwise the life of the inverter will be greatly shortened, and the failure rate of the inverter will also be significant. rise. We strongly recommend that users use the inverter at a level not exceeding 85% of rated power.
15. Q: What should I pay attention to when using a car inverter?
A: First of all, the inverter should be used strictly according to the user manual. Secondly, the output voltage of the inverter is 220 volts AC, and this 220 volt is in a small space and is movable, so it is extraordinarily Be careful. Keep it in a safe place (especially away from children!) to prevent electric shock. When not in use, it is best to cut off its input power. Third, do not place the inverter near the sun or the heater outlet. The operating temperature of the inverter should not exceed 40 degrees Celsius. Fourth, the inverter will heat up when it is working, so do not place objects near or on it. Fifth, the inverter is afraid of water, so don't let it rain or sprinkle with water.
16. Q: Why is the displayed voltage lower than 220 volts when using an ordinary multimeter to measure the AC output of a quasi-sine wave inverter?
A: This is normal, because the sine wave AC voltage should be measured using a universal meter with a 'true RMS' file to get the correct reading.
17. Q: How do I choose an inverter product?
A: The car inverter is a power product that works in high current and high frequency environments, and its potential failure rate is quite high. Therefore, consumers must be cautious when purchasing. First, select from the output waveform of the inverter, preferably not lower than the quasi-sine wave; secondly, the inverter must have complete circuit protection function; third, the manufacturer must have a good after-sales service commitment; fourth, the circuit and The product has been tested for a while.
Inverter, must be a kind of inverter device to be called, he and the transformer are directly different, that is, he can achieve DC input, and then output AC, the working principle is the same as the switching power supply, but the oscillation frequency is Within a certain range, for example, if this frequency is 50HZ, the output is AC 50HZ. An inverter is a device that can change its frequency.
Transformers generally refer to equipment of a specific frequency range, such as power frequency transformers, which are the transformers we generally see. Their inputs and outputs must be within a certain range, such as 40-60HZ.
Some Questions about Inverter
Date：2019-03-27 01:29:56 click：2209
