What causes the insensitivity of a push button switch? How to test its lifespan?

When the operating force is met, the switch: applies pressure in the operating direction, and the function of the switch is turned off and on. When the pressure is removed, the switch is closed, and its internal structure is made and closed by the stress change of the metal spring.

A push button switch refers to a switch that uses a button to push the transmission mechanism to connect or disconnect the moving contact and the static contact to realize circuit switching.

In the electrical automatic control circuit of the push button switch, it is used to manually send control signals to control contactors, electromagnetic starters, etc.

1. When the button is turned on, pay more attention to the force of squeezing, and do not turn on too large a switch. Otherwise, the switch may get stuck. The sensitivity of the switch will also be reduced later.

2. Do not press the button switch repeatedly too frequently, otherwise it will wear out the internal components of the switch spring and reduce the sensitivity of the switch spring in the back.

3. When using the push button switch every day, please note that there should be no water droplets or water vapor on the surface of the button. Otherwise, if water enters the switch, the humidity will affect the switch.

4. Every time you press the button, the internal shrapnel will be worn out, preventing the button switch from being pressed repeatedly; when the circuit breaker reaches a certain wear limit, it will cause damage to the switch element.

5. The performance of the shrapnel is degraded, and short circuit leakage will also occur in the subsequent stage. If the human body accidentally touches it, it may cause some dangerous discharge and other hidden dangers.

The pulling speed of the button switch during the test is related to the test life. In order to measure the correct service life, there should be a correct test pulling speed. Since the test life should reflect the service life during manual operation, the pulling speed of the motor test should be consistent with the pulling speed of manual operation. That is to say, the value of the manual pulling speed should be tested.

Using a millisecond meter to test the on-off time, the time it takes for the knob switch handle to be turned from one extreme position to another can be measured. The flipping speed can be calculated based on the flipping time and flipping distance, and the calculated speed is the average speed over the entire flipping distance. According to actual tests, the manual pulling speed will change from time to time when the operator is different, and the pulling time of the same operator will also change, averaging about one millisecond.

Under the test conditions of the above push button switch standard, the test pulling speed is specified in detail while the number of tests per minute is specified. The pulling speed is one inch second, that is, millimeter second. This means that a test speed must be specified, and the test speed value specified in this standard is close to the manual pulling speed obtained by our test. The difference may be caused by the difference in personal manual operation speed. It is reasonable for the manual operation pulling speed to be the motorized test pulling speed. For the sake of uniformity, the range is also narrowed to one millimeter second.