JPH0236270B2 - CHOTANPACHIRYOKI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an ultrashort wave therapy that cures neuralgia, muscle pain, etc. and promotes health by irradiating the human body with ultrashort waves and activating the affected part of the human body by increasing the temperature. It's about machines. Specifically, a variable capacitor is used to tune the capacitance according to changes in the capacitance of the conductor applied to the affected part of the human body, but this prevents the output transistor from being overloaded and destroyed when it is out of tune.

In this type of ultrashort wave treatment device, when the device is not tuned, the impedance of the tuned circuit decreases, so
The power supply current increases. Conventionally, a resistor is inserted into the power supply circuit to generate a voltage drop in proportion to the current, thereby lowering the power supply voltage of the output transistor and preventing loss. Another method is to detect the current as in the previous example, control the oscillation level of the oscillation circuit, and perform a negative feedback operation to lower the output level.

With the above method, heat generation due to voltage drop caused by the resistor and operation itself are not perfect.

In the present invention, changes in capacitance due to the way the conductor is held, the location of the affected area, etc., and untuned variable capacitor tuning result in low tuning impedance, which increases the drain current of the transistor and increases heat loss. This prevents damage from occurring.

An embodiment of the present invention will be described below with reference to FIG.

An oscillation circuit 1 generates an ultrahigh frequency output, a drive circuit 2 amplifies the power, and the amplified power is applied to the gate of a transistor 4 via a capacitor 3. The transistor 4 performs sufficient power amplification, and the inductance of the coil 5 and output coil 6 and the variable capacitor 7 as a variable capacitance element are
The capacitance enables tuning operation at ultrahigh frequency frequencies.
The output coil 6 supplies an ultrahigh frequency output proportional to the tap ratio n:1 to the conductor 9 for obtaining a medical effect, and irradiates the affected part of the human body with ultrahigh frequency waves.

The capacitance C _D of the conductor 9 is C _D = ε×ε ₀ ×S/d (ε: relative dielectric constant, ε ₀ : dielectric constant, S=area of the conductor,
d: distance between conductors). This is done through the output coil 6 (tap ratio n:1) as C _O = C _D ×
The capacitance at (1/n) ² affects the capacitance of this tuned circuit. Therefore, when the synchronization shifts,
Tuning impedance decreases, wasteful current flows, and heat is generated. Therefore, the ultrahigh-frequency current to be supplied to the conductor 9 is detected by the coil 8, and this current is rectified and smoothed by the diode 13 and the capacitor 14 to become a direct current positive voltage. FIG. 2 shows the output voltage V _P1 characteristics of the coil 8 due to variable capacitor tuning. This positive potential is divided into resistors 12 and 11, and a direct current bias is applied to the gate of the transistor 4 via the high-frequency blocking coil 10, and positive feedback is performed to increase the power amplification degree. In addition, resistors 11 and 1
2 needs to be adjusted depending on variations in the gate cutoff voltage of the transistor 4.

As described above, according to the present invention, when the tuning is achieved, the maximum current flows to the conductor, and at the same time, positive feedback is provided to the power amplifying transistor, thereby further improving the amplification degree. When the transistor is not tuned, the degree of amplification is further lowered, and even if the tuning impedance is lowered, the output current is regulated by the input voltage, thereby making it possible to prevent the transistor from being destroyed due to heat loss.

Therefore, how to hold the conductor, the location of the affected part of the human body,
It is possible to prevent changes in capacitance due to differences in thickness and dielectric constant due to the human body, and to prevent destruction of the transistor due to out-of-tuning of the variable capacitor.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram of an ultrashort wave treatment device according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram of the output voltage V _P1 of the current detection coil by tuning the variable condenser. 4... Current amplification transistor, 7... Variable capacitor, 9... Conductor.

Claims (1)

[Claims] 1 an oscillation circuit that generates an ultrahigh frequency output;
A power amplification transistor to which a very high frequency signal from this oscillation circuit is input to the gate and amplifies the power of the signal, and an output coil to which the output signal of this power amplification transistor is input and a conductor is connected to the output side. , a variable capacitance element that performs a synchronized operation between the inductance of the output coil and the capacitance of the conductor, and a variable capacitance element that detects the ultrahigh frequency current flowing through the conductor, rectifies and smoothes it, obtains a DC voltage, and converts the DC voltage. and a positive feedback circuit that applies a voltage to the gate of the power amplifying transistor.