Medical coil with modulation
To further improve the characteristics of the treatment coil was designed to Supplement the scheme with the ability of the modulation frequency. The main one is around 850..900кГц, and is both therapeutic and "transport" for frequency modulation, which, in turn, is in the range of 25 Hz..3 kHz. If the previous coil worked about the same for all bodies, are presented in this note can affect each of them more concentrated, according to their resonant frequency. Also, pratulananda frequency can have an impact on the organic system, for example, blood or lymph. To influence each of them has its own frequency according to the list .
Schematic diagram for this supplemented by a generator of rectangular pulses on DA1. In fact, these pulses have rise time and fall time, because the sine wave generator transistor VT1 correctly completes a series of pulses gradually reducing (increasing) their level. This mode is beneficial to the therapeutic effect.
Sine wave generator remains the same, however it now more correctly calculated the values of the capacitors C1-C4, applied a more powerful transistor, and the power scheme is of 12 volts. This made healing more powerful coil, which in combination with modulation now can have a deeper and more concentrated impact.
The operation of the circuit is simple. Generator DA1 on his 3rd leg produces rectangular pulses whose frequency is set by means of the resistance R2 and the capacitances C7 or C8, the choice between them is a switch SA1. From the position of this switch determines the range of modulation frequencies: when selected C7, the range of frequencies from 25 to 250 Hz, if you select C8, the range — 0.3..3 kHz. This relatively low frequency through the bias circuit R1-R2 is fed to the base of the driving transistor VT1, which together with the capacitances C1-C4 forms a sine wave signal generator. The frequency of operation is 850..900кГц. It is transmitted to the secondary winding of the coil L2, which produces a therapeutic effect on the body.
Switching frequencies can be different, for example, select a few frequencies according to the list  instead of AC soprotivlenie R3 to install some trimming mnogoobrazii, and switch to choose one of them. The capacitor C7 in this case will be shared.
As DA1 is the perfect timer NE555 (SE555), which has a fairly powerful output, simple switching circuit and the required range of supply voltage. Transistor VT1 — 2SC5200. Choke L3 — standard, 220 µh, for example like this. Diodes VD1, VD2 — UF4007, LEDs HL1, HL2 — any two or trehpaltsevye power 1W (at least). Actually coil with windings L1-L2 is wound in any way described here. Very good results showed the compact version. Socket XS1 standard, under apadter 12V. Variable resistor R3 is brought to the device panel and is calibrated. All the values of resistors and capacitors, it is desirable to withstand with accuracy of at least 10%. The timing circuit capacitors C7-C8 is desirable to choose a low temperature coefficient.
The only option of this scheme — to set the current consumption from the adapter to 75mA. This current is set by rotating potentiometer R1 in a mode where the modulation frequency is maximum. If the circuit is assembled correctly, then the other settings it requires. Confirmation of the correct operation of the circuit will glow LEDs HL1-HL2, which are both indicators of battery charge and the coil of the second magnetic field is required.