The figure is a circuit diagram of an ultrasonic mosquito repellent to produce 21-23 kHz. The power switch SW is closed, and the light-emitting diode VD indicates an operation signal. The single junction transistor VT1 and the resistor R1, the potentiometer RP and the capacitor C1 form an ultrasonic oscillating circuit. The power supply GB charges the capacitor C1 via R1 and RP. When the peak voltage is charged, the single junction transistor VT1 is turned on and discharged through the resistor R3. When the voltage across C1 falls below the peak point, the single junction transistor VT1 is turned off. The charge and discharge are repeated as described above, and oscillation occurs. Adjusting the potentiometer RP can change the oscillation frequency to be around 21-23 kHz. The oscillating signal is coupled to an amplifying circuit composed of VT2 via a capacitor C2, and the amplified signal is outputted by a capacitor C3 to emit ultrasonic waves to the piezoelectric ceramic buzzer BC.
What can the Screen Protector Cutting Machine do?
This is a customized universal cutting machine that can cut Screen Protectors and Back Films suitable for mobile phones, iPads, smart watches, etc.
One Cutting Machine can cut all types of Mobile Phone Screen Protectors. The cutting accuracy is 0.1mm. It can cut more than 14000+ mobile phone models and styles, and any model can be cut. 0 inventory, no need to worry about large inventory, to meet the large needs of customers.
Screen Protector Cutting Machine,Protective Film Cutting Machine,Back Sticker Cutting Machine,Phone Sticker Cutting Machine, Film Cutting Machine
Shenzhen Jianjiantong Technology Co., Ltd. , https://www.jonsun-sz.com