A push-button switch, also known as a momentary switch or a push-to-make switch, is an electrical component designed to establish or break an electrical circuit temporarily by pressing a button. It is commonly used in various electronic devices, appliances, control panels, and industrial applications. The working principle of a push-button switch can be explained as follows:
Contact Structure: A push-button switch typically consists of two main parts: the button or actuator and the contact structure. The button is the part that the user presses, and the contact structure is the internal mechanism that determines the electrical state of the switch.
Normally Open (NO) and Normally Closed (NC) Contacts: Push-button switches come in various configurations, but the two most common types are normally open (NO) and normally closed (NC). In the default state, a normally open switch does not allow current to flow through it, and a normally closed switch allows current to flow. When the button is pressed, the switch changes its state temporarily.
Spring Mechanism: Inside the switch, there is a spring mechanism that provides the necessary force to keep the contacts separated in their default state. This ensures that the circuit remains open in the case of a normally open switch and closed in the case of a normally closed switch.
Actuation: When the user applies pressure on the button, it compresses the spring mechanism. As a result, the internal contact structure changes its position.
Momentary Action: The push-button switch is designed for momentary action, which means that it only maintains the changed state while the button is being pressed. Once the user releases the button, the spring pushes the button back to its original position, and the switch returns to its default state.
Circuit Control: Depending on the application, the push-button switch can be used to control the flow of electrical current to perform specific functions. For example, in a basic application, a normally open push-button switch can be used to turn on a light or activate a motor when pressed, and then turn off when the button is released.
Push-button switches are widely used due to their simplicity and ease of use. They are particularly useful in scenarios where you need momentary control, such as starting/stopping a machine, signaling an event, or triggering a specific action in an electronic circuit.