The frequency of sound waves that the human ear can hear is 20 ~ 20,000,000 Hz. When the vibration frequency of sound wave is greater than 20000Hz or less than 20Hz, we can't hear it. Therefore, we call sound waves with frequencies higher than 20000Hz "ultrasonic waves".
The lower the ultrasonic frequency, the stronger the penetration. The general ultrasonic frequency used in the beauty industry is 1-3MHz.
Ultrasonic wave has the characteristics of good directivity, strong penetration, easy to obtain concentrated acoustic energy and long propagation distance. Therefore, it is applied to more and more industries.
Ultrasonic technology of beauty instrument has been popularized since it was introduced into the beauty industry in 1980s. Because of its wide treatment range, quick response, high cure rate and simple operation, it has become the most practical and popular equipment among many beauty instruments. With the progress of science and technology, a new generation of professional ultrasonic beauty instrument came into being, which swept the beauty industry with its excellent quality, powerful function and luxurious appearance.
The application of ultrasound in beauty industry mainly has the following functions.
1. mechanical action: mechanical vibration every second 1 10,000 times makes every affected part vibrate correspondingly, which plays a unique role in cell massage, improves cell metabolism function, enhances cell vitality, promotes blood circulation, improves skin tissue nutrition, and makes skin ruddy and elastic.
2. Warm effect: The warm effect of ultrasound can cause changes in vascular function and metabolic process, make blood circulation vigorous, reduce the excitement of cells, and produce analgesic effect. Relaxed and spasmodic skin has the function of relieving contracture.
3, chemical action: ultrasound has the function of strengthening catalysis and accelerating metabolism. The ph value can become alkaline. Conducive to drug penetration and improve the sterilization ability of drugs.
Second, analysis of ultrasonic schematic diagram of beauty instrument
1, ultrasonic schematic diagram of beauty instrument 2, ultrasonic head assembly of beauty instrument
In fact, the ultrasonic head is mainly composed of piezoelectric ceramic sheet and metal head. Among them, the piezoelectric ceramic sheet is an oscillating device, which oscillates at a high speed with the frequency of 1MHz, and the energy generated by it is transferred to the surface of the metal head through the metal head.
3. Circuit analysis
In this circuit, C2 C3 C4 Q2 L3 and the ultrasonic head * * * form a capacitive self-excited oscillation circuit. Special attention: when analyzing this circuit, the ultrasonic head should be analyzed as a capacitive device. Because the main device of the ultrasonic head itself is made of piezoelectric ceramics, it is actually a large capacitance, and the circuit will not vibrate without the ultrasonic head.
Q2 is the oscillator and the core of the whole circuit. When using it, the parameters should be selected according to the power supply voltage V 1 and the working current. Ultrasonic circuits on beauty instruments generally use a voltage lower than 48V.
L2 is a choke coil, its main function is to ensure that the working current will not be too large and burn out the oscillating tube.
Other devices * * * constitute the base adjustment circuit of the oscillator tube. The output size of the circuit is adjusted by RW 1, and the output size can also be made by single chip microcomputer.
This circuit is simple and durable, only need to install enough radiator for Q2. This circuit is basically used in ultrasonic beauty instruments on the market.
Ultrasonic beauty instrument: the heating degree of the probe does not represent the output power of sound waves, and overheating is easy to burn the skin; Water-based drugs with too small concentration should not be directly infiltrated, otherwise it will easily cause dry skin; When in use, the probe can not pass through the eyeball and can not massage the upper eyelid; Pregnant women and patients with severe heart disease cannot use it.
It is forbidden to operate beauty instruments: pregnant women; People who are inevitably exposed to strong (sun) light in their daily work; People who are allergic to light and drugs and people who are allergic to strong light sources; People with sensitive skin are susceptible to allergies; Epilepsy patients and people with scar constitution; Tourists' upper eyelids and parts with open wounds; Diabetic patients; For those who are using functional skin care products, stop using 1 0-3 months before operation; for those with high expectations, stop using essential oil 1 0-2 days before operation; for those with blackheads, it needs to be cleared for 3 days before treatment;