The inverter method shared today is the simplest and the lowest cost. There have been many manufacturing methods of inverters before. Of course, we hope that the simpler the better, the fewer components used, the lower the cost, and the clearer the words, the better.
As the name suggests, the inverter is the reverse working state of the normal transformer. What we use most is to convert 220V to 12V, but rarely from 12V to 220V. Because the power we use mainly comes from the power grid, the electricity we use comes from the power grid, and rarely turns the electricity we use into the electricity of the power grid. What's the significance of doing this inverter? You can understand that one is the enthusiasm of electronic enthusiasts, who are naturally fond of making. Another is that we are prepared for urgent needs. For example, in case the power grid stops supplying power, we can use the inverter to convert it into 220V, which will not affect the normal power supply in our home. Another is that with the popularity of solar panels, we may one day be exposed to the grid voltage that converts the power generated by solar energy into 220V.
Let's first look at the principle of our inverter
How about the simple schematic diagram? This is also the circuit that DIY often contacts. Through the circuit diagram, we can see that the components used have three resistors, two triodes and one transformer. Let me tell you each component one by one.
resistance
First, the next three resistors, the two resistors connected between the two triodes and the transformer, should not be too large, usually several ohms. If you want to be an inverter with high output power, the resistance should be smaller. If there is no such small resistance, you can use resistance wire to wind it. The other resistance is generally about 300 ohms. This resistance is connected to prevent the circuit from vibrating. When the load is different, the resistance may be slightly different. We can choose a sliding rheostat to adjust in real time.
triode
This time, we use the cheaper 3dd15, which is usually about 40 cents. The price is still very cheap, but the price is cheap but easy to use. The power is about 50W, which is suitable for low-frequency circuits. Our AC 50Hz is a real low-frequency circuit. If 50W does not meet everyone's needs, we can connect a triode 3dd15 in parallel on the basis of the original circuit, In this way, the output power will increase accordingly.
The NPN pin identification of this triode: the end with the word faces itself, the pin on the left is pole B, the one on the right is pole e, and the shell is pole C.
transformer
Let's talk about this transformer again. We can buy one on a treasure. If we want to make a high-power transformer, the transformer we buy also needs a high-power one. Of course, the price will increase correspondingly. This transformer is also the most expensive part. However, if we don't use the switching power supply design, this large transformer can be said to be a necessity. It's best to choose double 12V (plus or minus 12V) when selecting it, which corresponds to our circuit diagram, Of course, if you have enough ability, you can wind the transformer yourself.
After checking that the circuit is correct, connect a light bulb load at the output end and power on the inverter to see if the light bulb can emit light normally. If it cannot emit light, reduce the resistance. If the connection is correct, the light bulb can emit light normally.
Four elements are used as 12V to 220V inverter
transformer
Let's analyze it first. If we want to convert 12V DC into 220V AC, we need two processes. One is to boost voltage, and the other is to convert DC into AC. as for boost voltage, we may be most familiar with transformer (see the above figure). It can help us realize the transformation of voltage. We all learned that transformer can realize both voltage rise and voltage drop in high school, But one bad thing is that it can only realize the voltage rise and fall of AC, and it can only smile and don't talk to DC.
Circuit principle
We also use two groups of 12V transformers today. The so-called two groups are that the 12V input end has two input ports, that is, the blue wire in the transformer picture, and the white wire is the common end. In addition to this, we also need a triode resistor and 12V power supply. See the schematic diagram below for details.
From the schematic diagram, we can also clearly see the required components and the connection between various components. In terms of circuit function, in addition to transformer T1 for boosting and power supply V1 for power supply, the remaining components are the circuit that generates rectangular wave.
In terms of resistance selection, R1 and R2 are generally between 1.2k-4.7k. There is no special requirement for triode. Select according to the capacity of transformer. If the capacity is large, use the one with higher power; As long as the transformer has a power of about 12v-1037v, we can choose the transformer with a small output power of about 12V. Otherwise, we can't use the transformer with a high output power of about 12v-1037v as long as the transformer has a high output power of about 12v-7v.
The schematic diagram is very simple. As long as we know the function of these unit circuits and the boost principle, even if we know how to master it, it will be better if we know how to select components.
