Hello everyone, welcome to the Zimzim DIY channel. For this clip, it will be as easy as ever. I will take you to make your own inverter easily. Using a transformer from an old UPS as the main character, our main hero today. In the previous clip, I demonstrated how to create a simple AC power supply using a transformer, battery, and switch, which can make the light bulb blink. The light will be AC, but creating a frequency by hand, the frequency is not enough for use. So it makes the light bulb blink. Therefore, 1. The main factor that makes the light bulb brighter is the frequency. Therefore, if we can create a frequency for ourselves at a high enough frequency, we can make a simple inverter ourselves. Let's see the equipment we will use. The equipment is 1. 1 UPS transformer 2. 1 NPN transistor 3. 1 1Kohm resistor 4. 1 3.7V battery Why did I choose to use a UPS transformer? Because the UPS pot, let me imagine that One side is low voltage, it has 2 coils for us to connect and use. One coil we will use to create a frequency set. Another set will be the main set, allowing the current to pass through and induce a lot. And even though it has 2 coils, but there will be only 3 wires coming out. If this transformer is connected to the house electricity, receiving input from coil number 3, it will immediately become a step-down transformer. The middle wire will be the center tap or can be selected as Gnd. There will be electricity coming out of each pair. I'm not sure if it's about 7V or not. But if we are going to make an inverter, coil number 3 will be the output instead. Because the UPS transformer will have multiple output coils, that's because when the UPS is working and the output voltage drops, the relay contact will move to the coil with higher voltage. For finding the wires of a single UPS transformer set, we'll talk about it later. We will choose 1 output coil, which should be a pair of 220V. If we want to create an inverter, we need to feed the positive current from the battery into the center leg and take the other side of the coil to wait at leg C. As for the ground, continue to wait for the circuit at leg E. Now, the current from the positive terminal is waiting at leg C. But the current will not flow to the negative terminal of the battery if there is no positive current to bias leg B of the transistor here. Therefore, we will connect the remaining coil, the blue wire, to leg B, the yellow wire. But because the current is too much, it may damage leg B of the transistor. We will need to drop it with a 1Kohm resistor. Let's test it. Notice that the light bulb will be bright. I will explain its operation in the simplest way. It may be against the principle, but I think my friends should be able to imagine it. The current, as I said, will wait at leg C and wait at the switch. When we press the switch button, the light at leg B will be biased, causing the current at leg C to flow to leg E. When it can exit leg E, it will flow to the negative terminal of the battery. While it flows through the transformer There will be an iron field. This part can be studied further. Let's talk more. Let's say that the current of coil 2 flows back to the negative terminal faster. So it tells the current of coil 1 that the current flows easily on our side. When the current of the first side believes it, it follows. Then disaster occurs. When the current of coil 1 flows back, there is no current to bias leg B. The current from leg C cannot go to leg E. The current will stop. Therefore, the current from coil 1 tries to find a better way. It flows to leg B as usual. Now, there is a current to bias leg B. It will make the current from leg C flow to leg E. The current of coil 2 flows back to the negative terminal faster. It invites the current of coil 1 to come back. The current from coil 1 is gullible. It follows him again. When it follows, the current is not enough. The bias at leg B must return. The current from coil 1 is fooled over and over again. Never learned, when in the end, if it flows back to the second coil, it will always reach a dead end. It will work in a loop like this, repeatedly, infinity, at a speed of 700 times per second. Don't even mention the opposite coil. It doesn't care about the world. It only cares about the magnetic field that affects it. If that side moves forward, it moves forward. If this side moves backward, it moves backward. We can calculate this frequency from resistors, coils, and capacitors. Or, if you type in Google "RLC calculator", there will be websites that can calculate this frequency as well. But the problem with square wave wave is that there are sharp edges and corners. The transformer itself doesn't like this waveform very much. Because when used for a long time, the transformer will accumulate heat. Used with motors, there is a humming sound. The general AC home electricity wave that comes from the electricity authority will be a beautiful sine wave. But there is another wave that is a modified sine wave. It is developed from a square wave. The modified sine wave tries to design a wave shape that is like a sine wave. But the resulting wave shape is designed to be this much. It is a square and an angle. At present, it is still sold in the market as UPS computers, inverters. The advantages of the modified sine wave are: 1. Easy to design and produce The circuit is not very complicated. 2. Cheap As for the disadvantages, 1. There may be noise and motor devices may not work properly. For this clip, I would like to explain the operation here. See you in the next clip. Thank you to all friends who follow and watch.