NEW BOOSTER CONVERTER FROM 12 VOLTS TO 220 VOLTS

Hi all. Today I suggest that you get acquainted with another version of the voltage converter from 12 volts to 220 volts, and there are a lot of similar homemade products on the Internet, but this option was assembled using the H-bridge I invented. With such an assembly, it is possible to abandon the transformer, in which the secondary winding has an average output, and use an ordinary step-down transformer. I can’t say that I have a powerful converter, because I don’t have a decent transformer for the experiment.

https://www.youtube.com/watch?v=OYF-6ljHD7Q&t=3s

But let's start in order. I improved the control circuit for the operation of a home-made brushless motor, added two KT818 transistors, they convert a negative signal from the microcircuit in which the Hall sensor is located into a positive one. He, in turn, opens the mosfets and the voltage from the batteries is directly connected to one terminal of the motor windings, then to the other, causing the rotor to rotate. I wanted to make it beautiful, all in geometry, but the used resistors were all crumpled. Mosfets doubled in number and allocated a separate radiator for each channel

In the last article, I described a brushless electric motor. So, in the process of improving its parameters, I caught myself thinking that I had to deal with something similar, namely, the windings of the motor coils, such as those of a transformer used by radio amateurs in voltage converters. There are many such homemade products on the Internet, probably only the lazy did not try to collect them. The authors use microcircuits or multivibrators, which act as a master oscillator, they also control field-effect transistors.

In short, I put the engine aside for a while and continued to develop the theme with the converter in my own way. The idea was to abandon the transformer with a central output on the secondary winding.

But at the same time, he did not want to cut the amplitude of the oscillations. This is where the H-bridge that I invented earlier came in handy, if anyone doesn’t know, the H-bridge is a device that controls the rotation of the electric motor in one direction, or in the other, the control signal, I described it not so long ago.To the control unit from the brushless electric motor, while it is temporarily freed,

I added two small thyristors. Just don’t “hee-hee” here and spit, which ones were at hand, I applied them.

I thought for a long time how to drill a 4 mm thick aluminum plate, I already wanted to drill along the contour, then refine it with a file. And one morning I climbed into the pantry and stumbled upon a prefabricated drill with victorious plates. And it turned out so easily, as if it was not aluminum that was drilled, but oak.

As a result, after assembly and soldering, I received an H-bridge. The principle of its work is simple. When the control signal, I have it 12V, enters the input of the H-bridge, the pair immediately opens completely for me: a field-effect transistor and a thyristor, which excludes their heating.

The thyristor itself, when turned on, does not turn off, in the absence of a control signal. Even a field effect transistor will not break the power circuit. The thyristor will feed the gate of the transistor. An ordinary diode soldered to the control leg of the thyristor will fix this.

I checked the H-bridge, the power poles are transferred regularly, and the power reserve turned out to be decent. For each arm, two field-effect transistors IRFZ48 of 50A each and a thyristor T171-320-13 low-frequency 320A

He conducted an experiment, connected his motor to the output of the H-bridge, connected two wires of the windings together. At the input of the mosfets, he alternately applied a positive pulse with a frequency that he could give out by vibration of the hand. Received an alternating voltage of 12 volts, which spun the engine.

Well, if an alternating voltage can be obtained by dangling with a hand, then if we use a pulse generator, we get a stable voltage. For my converter, I used a Hall sensor chip, two magnets and an electric motor as a generator.

The chip turned out to be very Chinese (defective). When the magnet is near the sensor, the microcircuit switched the channel, and as soon as the magnetic field ceased to act, everything immediately returned to its original position, but in general, the switched on channel should only be switched by a magnet with a different polarity. I had to deploy one magnet, acting on the sensor with two magnets of the same polarity, everything was balanced. At the same time, you can now spin the motor with magnets not up to 3000 rpm, but up to 1500 to get 50 Hz. I set the generation frequency by ear, through the speaker, the accuracy is not very good, well, it’s not like state acceptance

I connected the generator to the H-bridge, put the power on. The tester showed alternating voltage. I connected the LEDs through a capacitor of three microfarads. They lit up, the voltage showed twelve volts. Probably everyone knows that direct current does not flow through the capacitor, and the LEDs light up ...

So you can try to connect the transformer. A transformer, like from a radio point, caught my eye.I didn’t dare to plug it into the outlet, I was afraid to provoke “BOOM”. But he connected it to the assembly, so he even gave out one hundred and twenty volts.

I went looking, rummaging through the barrels, found two more. One dwarf did not inspire confidence at all, and the second - when there is no other option - ... Yes, stocks were worn out.

As a load, I decided to take a lamp not an LED one, but a sixty-watt incandescent lamp, having soldered everything, connected it to the battery. The lamp flashed brightly, I measured the resulting voltage, it turned out to be 238 volts.

I don’t know whether to leave it for a more powerful drawdown under a load, or to play with the rotational speed of the generator motor. And yet, interacting with the magnetic field at the Hall sensor, is a sine or rectangular pulse generated?

I ended up building a one-of-a-kind 12-220 boost converter using a pulse generator, an H-bridge, and a simple step-down transformer.