The principle of work and research in the field of negative ions was carried out by A. L. Chizhevskiy [1] still in the middle of the last century. Developments made by his team, showed significantly positive effect of negatively charged air ions on humans, animals and plants [2]. The results of these studies in the USSR was adopted on the sanitary and epidemiological norms the optimal concentration of air ions in office premises. This mode has dezynfytsyrovaly the air and created conditions for efficient work. For a long time in the country can be found in the sale of "Chizhevsky Chandelier", which was specially designed for ionization of premises that has saturated the space with negative ions and, unlike many modern ionizers, almost did not create connections quite harmful ozone. A modern equivalent of this chandelier is we offer our readers.

Due to its small capacity, such a device is not suitable for ionization of the entire room, but to saturate the healthy negative ions (air ions) region of the workplace is ideal. In contrast to the germicidal lamps, this device does not require in their work to vacate the premises and can be turned on round the clock. The power source is a standard USB connector. Thus, it can be connected to any computer and placed next to him, improving the working environment for the user and dezinfectarea the space around it, including from viruses. The device consists of 10 inexpensive parts (Fig. 8), is reliable in operation and, in the presence of all the elements, going for a few hours.

Schematic diagram of the individual of the ionizer is shown in figure (1). It is based on involved circuitry and principle of the generator of high voltage pulses, which has proven itself a stable job, and low power consumption. For example, to achieve the same settings for the output voltage, a standard oscillator circuit on n-p-n transistor requires a few Watts of power. Our device will consume only 0.5 Watt.

The circuit operation following. The 5 V supply comes from the USB connector XS1 and further through the fuse FU1, to a schema. Transistor VT1 is assembled a generator that emits short pulses (of the order of 300-400 NS) to the primary winding of high voltage transformer TV1. Due to the large inductance in its secondary winding is formed sinusoidal voltage with an amplitude of about 30 kV high voltage coming through the rectifier diodes VD1-VD2 to the antenna AN1. Its design is a broom of sharp needles, which ionize the air and thereby form a stream of negative ions. Short pulses at the drain of the transistor occur due to the positive feedback formed by the current transformer TC1, which is a missed ring with the wire from the primary winding TV1. Chain R1-ZD1 sets the voltage bias to the gate of VT1.

You can do without it and miss this part of the notes, but for more reliable device would be better still to rework the transformer TV1 via the following method. Initially, parts of the transformer are connected by a plastic adhesive tape (Fig. 2). It is necessary to remove and disassemble the transformer (Fig. 3). Now you need to glue the ends of the ferrite instant glue and assemble the transformer so that they stuck together. Important: between the ends is supposed to be paper gaskets that can withstand the necessary clearance; they must not forget to establish into place during Assembly. Until the glue has dried, you need to insert a previously prepared sleeve (Fig. 4) between primary and secondary windings (Fig. 5). To give the design time to dry.

Now the transformer has become more reliable and more high-voltage.

The most important element of the circuit is a current transformer TC1. It fully defines the characteristics of the pulse in the primary winding TV1, and hence power input and high voltage output. The main thing here is to pick the right ferrite ring: it is smaller, the better. The author used a ferrite ring sizes 10*6*2 mm (2 mm height), which was wound 10 turns of wire in Teflon insulation. The diameter here is not important, the important thing is that in the middle of the ring it leaves a gap for the passage through it of the wires from the primary winding TV1 (see Fig. 1). With a larger diameter and the height of the ring, the pulse width becomes larger and the scheme might not work, so choose only these or the smaller its size.

For a list of other elements of the scheme:

• TV1 — ready high-voltage transformer;
• VT1 — transistor mosfet protection on the input FS7KM;
• VD1-VD2 — high voltage fast diodes 2CL77;
• ZD1 — Zener diode 4.7 volt 1N4732A;
• cord with a standard USB plug from any device;
• FU1 is the fuse of 1 A.

First of all, you need to prepare the transformer TV1. To do this, connect two primary windings in sequence: so that its total inductance becomes a maximum (Fig. 6).

Next, we must determine the design of the device: to what basis we will strengthen cost and other elements. The author chose to do this rather raspostraneny in the plumbing products clutch PP with a diameter of 50 mm and a length of 105 mm and a stub to it (Fig. 7). It is important that the clutch was supplied with two rubber gaskets. Dimensions of the clutch will determine the dimensions of the entire device as a whole (Fig. 13).

For placement and future planned connection of radio you can take the half from breadboard 4x6 cm, the edges of which are cut, that Board fits on bottom of stub (Fig. 8, 11). Then solder the components together according to the above concept. You should get something like this (Fig. 9). Note: the secondary winding TV1 should be the findings upwards.

With proper operation, which will be described below, the transistor VT1 becomes slightly warm and setting it on a radiator is not required. Also, do not heat up and the remaining elements of the scheme.

Placed Board, once configured, is housed in the plug, and the plug then inserted in the socket. Approximately one third of its height, the circumference of the coupling, you must drill 7-9 holes for ventilation. The second side of the clutch closes any plastic mesh. The mesh is cut with scissors by the diameter of the hose and secured there with a rubber o-ring (Fig. 13).

Cord with a USB connector can be recovered from any device or adapter. The cord contains four wires, two of which is the supply that you need to solder to the circuit. As a General rule: red is plus 5V, black is negative (common). But it's better to double-check tester, and then connect.

To set up the scheme, it is necessary to apply 5 volts from the power supply and measure current consumption. If this current is greater than 0.6 ampere, it means that you need to swap insights current transformer TC1. It is also desirable to measure the waveform at the drain of the transistor VT1. It is shown in figure (10), where the yellow-ray — runoff and green — gate of this transistor. Note: the waveform may be different, for example, the bundle may be a larger number of impulses; it is the presence of unipolar pulses, which duration must be 300-400 NS, and an amplitude of the order of 300-400 V.

If everything is working correctly, then between terminals of the secondary winding TV1 we need to obtain the spark gap of 8-9 mm (or slightly more). In this case, we podpaivaem one of these insights to minus (the scheme), and the second — two series-connected diode is VD1-VD2. Don't forget that their net they must be connected to the coil, and the advantage — to the antenna AN1. The antenna is made of one or two pieces (4-5 cm) of the core wire, which then have to fluff up one side, and the second solder these diodes (Fig. 12). Fluster Board insights from the cord of the USB connector placed the Board inside the turn and fasten it there with glue gun. Diodes also it is desirable to raise above the Board and secure it on the casing stub in the same way. Then insert the plug in the coupling. If you have chosen the design, we should obtain an external view of the device shown in figure (13).

You can check the operation of the device even in the assembled state with the help of this indicator. It needs to glow when held to the middle of the clutch.

Do not forget to ventilate the room, which is important not only when working with such devices, but also for ordinary life!

In addition , you can add that the presented scheme can be powered from battery, 4.8 V (example), charge which is enough for 12-15 hours of continuous operation. Such a device can carry, for example, hanging it around his neck with a chain. However in this case, most likely will need some other basis for placement of her parts.