The micro switch is a pressure-activated fast changeover switch. The micro switch is covered with a shell and has a drive rod on the outside. Because the contact spacing of the switch is relatively small, it is also called a micro switch. Sensitive switch. This time, follow ZINGEAR to learn more about how to choose a micro switch.
The overall size of the micro switch affects the size of the micro switch. Size is very important when selecting a micro switch. ZINGEAR reminds us that the size of the microswitch is directly related to its characteristics, including current range, stroke, and operating force; applications requiring larger currents usually require larger microswitches. The smaller the size of the switch, the smaller its stroke and the current it can break. The smaller. In addition, ZINGEAR reminds us that the external dimensions of the microswitch also affect the operating force.
ZINGEAR introduces Understanding Electrical Requirements Micro switches are typically capable of breaking current from 5 mA/5 V DC to 25 A/250 V AC. Engineers must know the rated current and voltage (AC or DC) required for the specific application to select a Suitable micro switch; In addition to load requirements, ZINGEAR reminds engineers that they must also choose the appropriate circuit.
ZINGEAR introduced that considering the environmental conditions of use, environmental requirements have a great impact on the selection of micro switches, especially in applications that require high reliability and criticality such as industrial control and medical equipment. Understand the environmental conditions of the application, including contaminants in the air that may enter the microswitch, the liquid the microswitch is in, and operating temperature requirements. ZINGEAR reminds us that for applications under harsh environmental conditions, it is necessary to choose a sealed switch with a wide operating temperature range; at the same time, it is also important to note that the protection level of the micro switch should be at least IP67 to prevent liquid intrusion.
ZINGEAR introduced that it is critical to clarify the working life requirements of micro switches. ZINGEAR reminds that different micro switches have different contact materials, shells, and terminals, which can meet the electrical and mechanical life requirements in different applications; as for the subtle price differences between switches of different quality, the total cost of use needs to be taken into consideration. Pay the price to ensure that the micro switch operates trouble-free for a long time.
1. Appearance of micro switch
The appearance is smooth, the workmanship is good, and it looks comfortable. Then there is the observation of the power switch frame, the size of the gaps, etc. These are mainly to analyze the workmanship of the switch, followed by the design, including leg length, angled straight legs, button design, etc.
2. Microswitch material composition
The plastic materials we call switches are all PC materials, which are a kind of polycarbonate that is flame retardant, anti-distortion, impact resistant, not easy to dye, and smooth in appearance. If the surface color is white, then 8 is PC material, but most of the products on the market switches are black, called black yeast, which is also a polycarbonate material. If the smoothness is low, it may contain less polycarbonate. Then there are the legs. There are three materials for the power switch legs. The three materials commonly used on the market are iron, stainless steel, and copper legs. The surface of the legs is generally treated with tin plating so that the switch legs are all the same color. Use a small knife to You can tell them apart by scratching them.
3. Switch shrapnel structure
At present, the internal shrapnel materials used in China are all stainless steel SUS301 materials. Many foreign countries use 304 stainless steel as the material. To distinguish the quality of the shrapnel, we need a professional shrapnel life test, then the feel test, and finally the button sound.
4. Microswitch service life
First, add 250gf force test in any direction for 2 minutes. There are no cracks, looseness, or other abnormalities in the row of limbs. The mechanical and electrical performance is satisfactory. No load: Operator at 18-30 times per minute. Conduct a no-load test of 100,000 times.
5. How to use a microswitch
The wiring method can directly affect the resistance charge of the power switch. The best wiring method is card wiring, which means directly plugging into the wiring hole behind the switch. This reduces the assembly time of electronic products, saves materials, and especially improves Resistance charge size.
Microswitch wiring method
When it comes to the wiring method of the microswitch, it is actually very simple. Generally speaking, from the wiring diagram of the micro switch, the micro switch has three points, one is the public point, one is the normally open point, and one is the closed point. The common point is like the neutral wire in a socket, and the normally open point is the point where the switch is turned on and the current flows. The closing point is of course the contact point through which current flows. According to the wiring diagram of the microswitch, connect the corresponding points to the corresponding positions. Although the wiring method of the micro switch seems simple, relevant preparation measures need to be taken.
Microswitch wiring/principle
In micro switches, the rotating elements include buttons, push pins, rollers, and levers. As long as an external mechanical force is applied to the spring leaf through the rotating element when the spring leaf moves to the critical point, an instantaneous action will occur, causing the spring leaf to contact the contact point, thereby achieving disconnection and quick connection. From the wiring method of the microswitch, we can also see its working principle. As for the wiring diagram of the micro switch, it can only be used as a reliable reference design drawing during wiring operations. The entire design circuit can be clearly defined so that there will be no problems with the wiring in the middle.
Microswitch wiring/structure
We should carefully study the structure of the micro switch for a better understanding of this switch. As for the wiring diagram of the microswitch and the wiring method of the microswitch, it is not as important as the structure of the microswitch. A switch must have a breaking point, a closing point, and a common point. In addition, rotary switch components such as buttons, levers, springboards, brackets, electrical contacts, reeds, etc., are also necessary for the micro switch structure. In the wiring of micro switches, the power supply parts that serve as electrical output and input are called terminals, which are also very important in the wiring of micro switches.
Precautions for microswitches
(1) When fixing the switch body, please use M2 small screws to fix it on a smooth surface with a torque of 0.098N·m or less. In addition, to prevent the screws from loosening, it is recommended to use washers at the same time
(2) Please note that the action body should not directly exert force on the button or actuator in the free state. When using, the button should exert force in the vertical direction.
(3) The standard setting for the operation after operation is 70[%] or more of the O.T. value. In the case of a switch, do not set the operating body at the operating limit position to avoid shortening of life due to opening and closing and overtravel caused by impact.
(4) In the case of hand soldering, please use a temperature-adjusted 320°C electric circuit, complete the work within 3 seconds, and be careful not to exert force on the terminal part during the work.
(5) When used under low current and voltage conditions, it is recommended to use the low-power circuit type (Au-clad contacts).
ZINGEAR specializes in the production and sales of micro switches, waterproof micro switches, automotive micro switches, power switches, rotary switches, and other products. Welcome to consult and cooperate!