Manual electric grinder has the characteristics of small volume, light weight and flexible operation, and is suitable for processing surfaces with various angles and complex shapes, and is applied to the production of handicrafts such as wood carving, jade carving, nuclear carving, bone carving and stone carving. As a powerful and easy-to-operate electric tool, users can easily complete various processing tasks with it.

First, the composition and working principle of manual electric grinder products

Manual electric grinder products are usually composed of several parts. The motor is the core component of the electric grinder and is responsible for providing power. The motor includes key components such as rotor, stator, brush and bearing. The grinding disc is a key part of grinding operation, which is composed of multiple metal gears and grinding heads. The transmission system is responsible for transmitting the power of the motor to the grinding disc to ensure that the grinding disc can rotate smoothly and at high speed. The control system is used to adjust the rotational speed and grinding intensity of the motor to meet different machining requirements. The shell and accessories are convenient for users to carry out various processing operations.

The working principle of the manual electric grinder is mainly based on the rotating motion of the motor. When the motor is energized, the current passes through the stator coil of the motor to form a magnetic field, which interacts with the magnetic poles on the rotor to generate electromagnetic force, which makes the rotor start to rotate. The rotor transmits the rotary motion to the grinding disc through the shaft, which makes it start to rotate at high speed.

Manual electric grinder products usually include four parts, charging management, battery protection, motor drive and motor control. The charging management of manual electric grinder products involves the management and control of battery charging process to ensure that the battery can be fully charged safely and efficiently and prolong its service life. Common battery types include nickel-hydrogen batteries and lithium-ion batteries. Lithium-ion battery has been widely used in manual electric grinder because of its high energy density, long cycle life and low self-discharge rate. During the charging process, the charger will monitor the voltage, current and temperature of the battery to ensure that the charging process is carried out within a safe range.

At the same time, the charger will also adopt charging strategies such as constant current charging and constant voltage charging to ensure that the battery can be fully charged and prolong its service life. There are also overcharge protection, overdischarge protection, short circuit protection and temperature protection. When the battery voltage exceeds the predetermined maximum value, the overcharge protection circuit will start, which is realized by MOS tube connected to the battery voltage sensor. When the voltage exceeds the preset threshold, the MOS tube will be turned off, thus disconnecting the power supply from the battery to prevent the battery from being damaged.

The motor drive of manual electric grinder is the core part of its work, which is responsible for converting electric energy into mechanical energy, thus driving the grinding disc or grinding head to rotate and grind. Usually, DC motor or AC motor is used as the driving source. In order to ensure the safe operation and prolong the service life of the motor, the manual electric grinder is usually equipped with safety devices such as overload protection and overheating protection. When the motor is overloaded or the temperature is too high, these safety devices will automatically cut off the power supply to prevent the motor from being damaged. In the motor drive circuit, MOS can accurately control the operation of the motor and improve the efficiency and stability of the motor by using its fast switching characteristics.

2. What discrete devices are needed for the manual electric grinder?

Taking a product in the market as an example, the small lithium battery electric grinder is compact in shape, comfortable to handle, fully functional in hand carving and polishing, and has five-speed adjustment, which can be adjusted between 5000-28000 rpm. The maximum output power is 64W, and a lithium battery with 8V1Ah capacity is built in. The rated voltage of the motor is 7.2V. The inside of the electric grinder is mainly composed of three small plates, two series of lithium batteries, a motor and a rotating shaft. The total consumption of Wei 11PCS discrete device products, including diodes, triodes, three-terminal regulators and MOS tubes.