Working principle and usage instructions of electric hand drill speed switch

　　Working principle and usage instructions of electric hand drill speed switch

An electric hand drill is a drilling tool powered by AC power or a DC battery. It is a type of handheld power tool. The electric hand drill is the largest-selling product in the power tool industry and is widely used in construction, decoration, furniture and other industries. Making holes or holes in objects is also called an electric hammer in some industries.

The main components of an electric hand drill: drill chuck, output shaft, gear, rotor, stator, casing, switch and cable.

Electric hand drill (pistol drill) – a tool used for drilling holes in metal materials, wood, plastics, etc. When equipped with a forward and reverse switch and an electronic speed control device, it can be used as an electric screwdriver. Some models are equipped with rechargeable batteries, which can work normally without external power supply for a certain period of time.

The speed control switch changes the average current power on the load from 0-100% by changing the duty cycle of the output square wave, thereby changing the load, light brightness/motor speed. The pulse width modulation (PWM) method is used to realize dimming/speed adjustment. Its advantage is that the energy power of the power supply can be fully utilized and the circuit efficiency is high. For example: when the output is a 50% square wave, the output energy power of the pulse width modulation (PWM) circuit is also 50%, that is, almost all the energy is converted to the load. When using common resistor step-down speed regulation, in order for the load to obtain the maximum 50% power of the power supply, the power supply must provide more than 71% of the output power, of which 21% is consumed by the voltage drop and heat consumption of the resistor. Most of the energy is consumed in the resistor, and the remaining energy is the output energy, and the conversion efficiency is very low. In addition, the HW-A-1040 speed regulator has almost no heat consumption due to its switching method. The HW-A-1040 speed regulator has very large torque at low speeds because the speed regulator has automatic tracking PWM and uses pulse width modulation. (PWM) mode allows the load to obtain almost full power supply voltage during operation, which is beneficial to overcoming the inherent coil resistance of the motor and allowing the motor to generate greater torque power.

Instructions for use:

1. Before use, the electric drill should be idle for 0.5 to 1 minute to check whether the transmission part is flexible, whether there is any abnormal noise, whether the screws are loose, and whether the commutator spark is normal.

2. For electric hand drills with metal shells, protective grounding (zero connection) measures must be taken.

3. Before use, make sure the hand drill switch is off to prevent the hand drill from suddenly turning when the plug is inserted into the power socket.

4. Check the power cord for damage before use. If so, it must be wrapped with insulating tape. During use, it must not be soaked in water or dragged around, and it must not come into contact with heat sources and corrosive media.

5. When drilling, you should hold the electric drill firmly with both hands. Try not to operate it with one hand. You should master the correct operating posture.