# 220 volts from a 3.7 V battery

In everyday life, we most often encounter power supplies that lower the high voltage on the network to a few volts, which are necessary for connecting various devices. However, you can do the inverse transform. Moreover, the scheme is quite simple. It can be useful in two cases:
• In order to connect appliances and devices that are powered from only 220 volts in the field.
• In the event of a power outage.
Well, don't forget that experimenting is always entertaining. For example, I assembled this design simply out of interest, without a sight for practical use. However, it should be noted that the presented converter of low power and will not withstand a large load, such as a TV. However, as will be seen in the example, the energy-saving light bulb works on it.

## Making the converter

We need only a few details:
• Transformer from the old charger for the phone.
• Transistor 882P or its domestic counterparts KT815, KT817.
• Diode IN5398,analogue KD226 or in general any other designed for reverse current up to 10 volts of medium or high power.
• Resistor (resistance) per 1 kΩ.
• Small breadboard.
Still naturally you will need a soldering iron with solder and flux, wire cutters, wires and a multi-meter (tester). Of course, you can also make a printed circuit board, but for a scheme of several parts, it is not worth spending time on developing the layout of the tracks to draw them and etch the foil-plated PCB or getinax. Check the transformer. Old charger board.
Transformer discharged from it.
Next we need to check the transformer and find the leads of its windings. Take a multimeter, switch it to ohmmeter mode. In turn, we check all the conclusions, we find those that pair "call" and write down their resistance. 1. The first 0.7 Ohm.
2. The second is 1.3 Ohms.
3.Third 6.2 Ohm.
The winding with the primary resistance was 220 V. In our device, it will be secondary, that is, the output. From the rest, an undervoltage was taken. Here they will serve as the primary (the one with a resistance of 0.7 ohm) and part of the generator (with a resistance of 1.3). The results of measurements for different transformers may differ, you need to focus on their relationship with each other.

## Device Diagram

As you can see, it is the simplest. For convenience, we have marked the resistance of the windings. Transformer cannot convert direct current. Therefore, the transistor and one of its windings assembled generator. It delivers a pulsating voltage from the input (battery) to the primary winding, the voltage of about 220 volts is removed from the secondary.

## We assemble the converter

Take the breadboard.
Install a transformer on it. Choose a resistor in 1 kilo. Insert it into the holes of the board, next to the transformer.Bend the terminals of the resistor so as to connect them with the corresponding contacts of the transformer. Solder it. It is convenient at the same time to fix the board in whatever clamp, as in the photo, so that there is no problem with the missing "third hand". Soldered resistor. Excess length of the output is biting. Board with bitten by the resistor. Next, take the transistor. We install it on the board on the other side of the transformer, as in the screenshot (I picked up the location of the parts so that it was more convenient to connect them according to the concept). Bend the terminals of the transistor. Solder them. Mounted transistor. We take the diode. We install it on a board parallel to the transistor. We solder. Our scheme is ready.
Solder the wires to connect the DC voltage (DC input). And wires for pulsating high voltage removal (AC output).
For convenience, we take 220 volt wires with crocodiles. Our device is ready.

## We are testing a converter

In order to apply voltage, we select a battery of 3-4 volts. Although You can use any other power source.
Solder the wires of the low voltage input to it, observing the polarity. We measure the output voltage of our device. It turns out 215 volts.
Attention. It is not advisable to touch the parts with the power connected. It is not so dangerous if you have no health problems, especially with the heart (although two hundred volts, but the current is weak), it can be tingling unpleasantly. We end the testing by connecting a 220 volt fluorescent energy-saving lamp. Thanks to the "crocodiles" it is easy to do without a soldering iron. As you can see, the lamp is on.
Our device is ready. Tip.You can increase the power of the converter by installing a transistor on the radiator. True battery capacity not long enough.If you are going to use the converter all the time, then choose a more capacious battery and make a case for it.