Experiments with magnetic field treatment are now becoming relevant. Earlier for this purpose it was recommended that wearing magnetic bracelets. Although the effect of their use is still controversial, many use them all the time. Recently developed small-sized electronic device that can be worn as magnetic bracelets, but affecting the body variable field at the specific frequencies.

These intuitive devices are used as a pain reliever for headaches and migraines, as a stimulant with nervousness and fatigue, and to relieve rheumatic pains and etc.

The frequency of the magnetic field is adjusted individually by using the appropriate switches. Typically, lower frequencies are used when removing rheumatic pains and a higher head. Minimum time daily session - 15 minutes. Miniature design the device enables you to attach the belt to the arm, leg or other body parts.

The proposed variant of the device for treatment with magnetic field (Fig.1) contains a single chip - timer CREW. The timer is used to generate pulse signals of the required frequency. The supply voltage Ie=5...16 V, the instability of the repetition period of the generated pulse signals from the supply voltage is 0.01% [I]. The timer is implemented in bipolar technology, and its powerful output stage provides current IOUT=200 mA.

Fig.1

The operation of the circuit (Fig. 1) can be explained as follows. In the initial state, the capacitor C2 is discharged. He is charged through resistors R1, R2, R3. The voltage on the capacitor increases exponentially, approaching PI. When the voltage reaches the value of 0.7 Ie, the internal transistor circuits is triggered and switches the trigger, causing the pin 3 there is a low voltage level. Now the capacitor discharges through the resistors R1, R2, R3, and the voltage is reduced to a value of 0.3 SP. At this point, the trigger returns to its original state, and at pin 3 is set to a high level. The pulse duration t and pause tп output are t=tп= 0,69 R...C2, where R is the total value of the included resistors.

NN
p/p

A closed switch

Pulse frequency, Hz

1

S1

0,74

2

S2

1,2

3

S3

3

4

S1+S2

2

5

S1+S3

4

6

S2+S3

4,5

7

S1+S2+S3

5,2

By switching of switches S1, S2 and S3 may receive seven values of the values of the frequency pulse signals listed in the table. If necessary, a more accurate setting frequency resistor values R1, R2, R3 are selected, performing their two series-connected resistors.

In Fig.2 shows a printed circuit Board device size h mm. Solenoid L1 is a size 12,5x22 mm and contains 4300 turns of wire PEL of 0.09, the Core of the electromagnet - magnetic steel (Fig.3).

Fig.2

Fig.3

The inductance of the assembled electromagnet - 270 mH, DC resistance - 300 Ohms. As the electromagnet is possible to use electromagnets from compact low-impedance relays, such as the RES-6, passport of the Russian Federation 0.452.104.

The device is powered with 5V, 9V or 15V depending on the recommended dose, and current consumption is respectively 15, 30, or 50 mA.

Literature

1. Los G. I., T. Y. Novoseltsev Design of discrete devices-integrated circuits: a Handbook. - M.: Radio and communication, 1990. - 303 p.

Author: E. Stakhov, Grodno; Publication: N. Bolshakov, rf.atnn.ru