What is the working principle of car inverter?
The general car inverter is mainly composed of inverter bridge, filter circuit, control circuit, oscillator, etc. Its working principle is to convert the 12V DC supplied by the car battery into 30kHz-50kHz, 220V or so AC through the high-frequency PWM (pulse-width modulation) switching power supply technology first. Then use the bridge rectifier, filtering, pulse width modulation and switching power output technology to convert the 30kHz-50kHz, 220V AC power into 50Hz, 220V AC power.
Car Inverter
The simplest car inverter may only have a two-pin connector and a cigarette lighter power input connector from the outside, but its internal structure is equally complex. Car inverter internal circuit with MOS field effect tube, the device will produce a certain amount of heat in the work, so it will be equipped with a heat sink, and the larger power inverter will be equipped with a small cooling fan.
1, power selection
Looking at a wide range of inverters, how do we buy? First of all, we need to know what electrical devices we need to use in the car, and then choose the specifications of the inverter according to their power. In addition, we must also consider the melting current of the car cigarette lighter fuse.
If the power of the electrical appliances to be used is more than 180W, you can also use the battery connection cable to connect the high-power inverter directly to the battery, but this method can only be used in emergency, and should not be used for a long time, otherwise it will cause damage to the battery itself. The output power of the car inverter must be greater than the power of the electrical appliances, and there should be enough margin for some electrical appliances with high starting power, otherwise it is likely to be unable to start.
2、Output Interface
After selecting the specifications, we will look at the output interface of the inverter itself. At present, many electrical appliances use a three-pronged plug, which requires a three-hole interface on the inverter, in addition, the USB interface is also quite useful, so it is best to choose three interfaces have inverters.
The inverter we used to test a home purifier in Xingtai last week only had one socket, so we bought a temporary terminal block. If the inverter itself comes with three kinds of sockets (two-pin, three-pin and USB), it will be more convenient to use.
3. Output waveform
In addition, according to the different output current waveforms, car inverters are divided into pure sine wave inverters and modified sine wave inverters. Among them, pure sine wave inverters have stable power supply and can basically drive common electrical appliances well. Corrected sine wave is actually closer to square wave, and the quality of output current is poorer, which will cause some damage to some electrical devices.
Although the price difference between the two types of inverters is large, we still recommend you to buy a pure sine wave inverter if you are using it for a long time. Because no matter which type of electric equipment, when using pure sine wave inverter to supply power, just like connecting to the mains at home, you don't have to worry about damaging your electric appliances.
4、Protection function
When choosing a car inverter, make sure it has over-voltage shutdown, under-voltage shutdown, over-temperature protection, over-current protection and short-circuit protection, etc. These functions not only protect the inverter itself, but more importantly, avoid the damage of the power equipment.
