A relatively complete ultrasonic generator circuit

This more complete ultrasonic generator is shown in the figure below.

It has a timer that can limit the generator to work in a continuous waveform state or in a high voltage pulse state with adjustable width within a duration ranging from a few seconds to a few minutes. It can also generate additional modulation by a pulse current with a frequency of 100Hz.

The modulator and timer of the device are formed by the integrated circuit DA1.

DA1.1 and DA1.2 form a multivibrator with adjustable pulse period (R3). DA1.4 forms a timer. The push button switch SB1 is used to start (trigger), and the exponential potentiometer R6 is used to adjust the time length. The transistor converter VT1 is controlled by the control units DA1.3, DA1.4 and the conversion switch SA1, and is connected to the base-emitter junction of the transistor VT2. VT2 is a high-voltage pulse generator. The generator can be powered by the power supply part of Figure 2. At this time, it is necessary to pay attention to the polarity of the semiconductor components and electrolytic capacitors in the power supply part.

In the circuit, the transformer can be a TV line scan output transformer. The operating frequency of the generator is about 48kHz, and the output voltage is 6-8kV. The power transistor and the three-terminal voltage regulator integrated circuit should be equipped with a heat sink. The current consumed by the generator is not more than 300mA. As the output electrode, a gas-filled indicator bulb VL1 can be used, and only one electrode (or cathode or anode) is connected, such as a neon indicator tube. The second electrode is the human tissue to be treated. When the gas-filled indicator bulb contacts the human tissue, a discharge current is generated. Depending on the type of gas filled, the degree of dilution and concentration determines the color of the light emitted by the lamp (tube), neon-orange red, pink; argon-purple; helium-light green and purple; hydrogen-bright sky blue, etc.

DA1 uses K56KT3; VT1 uses KT3151, and VT2 uses KT805AM.

Biomedical electrodes are used to measure the biopotential of human and animal bodies, and are also used to apply current (voltage) stimulation to biological tissues or organs to cause certain changes in the body to achieve medical purposes. There are many types of electrodes, including surface electrodes and internal electrodes. Generally, a single electrode is made of metal, which can conduct current between the organism and the medical instrument. Ideally, this current is very small. Here, a gas-filled indicator light (neon lamp) is used instead of an electrode. The two electrodes of the neon lamp are very close to each other and are sealed in a glass bulb filled with neon gas. When a voltage is applied to the electrodes, the negative electrode produces a glow discharge. When an alternating voltage is applied, the two poles alternately become positive and negative, and a continuous glow discharge is generated between the two poles. In this application example, one electrode is connected to the secondary pole of the transformer, and the other electrode is the human tissue.

Note: This device is only allowed to be used under compliance with technical safety conditions (such as AC power supply, grounding wire, good insulation performance of the power transformer, etc.) and under the diagnosis and advice of a doctor.