How to Use Pushbutton STOP: Examples, Pinouts, and Specs

The Pushbutton STOP is a momentary switch designed to interrupt an electrical circuit when pressed. It is commonly used in safety-critical applications to stop machines, processes, or systems in emergency situations. The switch is typically red in color for easy identification and is often integrated into control panels or machinery.

• Emergency stop buttons in industrial machinery
• Safety controls in automation systems
• Power interruption in motorized devices
• Reset or stop functions in electronic circuits

1. Identify the Terminals: Locate the COM, NO, and NC terminals on the pushbutton.
2. Connect the Circuit:
   • For a Normally Open (NO) configuration, connect the circuit to the COM and NO terminals. The circuit will close when the button is pressed.
   • For a Normally Closed (NC) configuration, connect the circuit to the COM and NC terminals. The circuit will open when the button is pressed.
3. Mount the Button: Secure the pushbutton in a panel or enclosure using the provided mounting hardware.
4. Test the Circuit: Verify that pressing the button interrupts or completes the circuit as intended.

• Voltage and Current Ratings: Ensure the pushbutton is rated for the voltage and current of your circuit to avoid damage or failure.
• Debouncing: When used in digital circuits, implement debouncing (hardware or software) to prevent false triggering due to mechanical bounce.
• Safety Compliance: For industrial applications, ensure the pushbutton meets relevant safety standards (e.g., IEC 60947-5-1).
• Wiring: Use appropriate wire gauges and secure connections to prevent loose or faulty wiring.

The Pushbutton STOP can be used with an Arduino UNO to stop a process or trigger an emergency shutdown. Below is an example circuit and code:

• Connect the COM terminal of the pushbutton to the GND pin of the Arduino.
• Connect the NO terminal of the pushbutton to digital pin 2 of the Arduino.
• Use a pull-up resistor (10kΩ) between digital pin 2 and the 5V pin of the Arduino.

// Pushbutton STOP Example with Arduino UNO
// This code monitors the pushbutton and stops a process when pressed.

const int buttonPin = 2;  // Pin connected to the pushbutton
const int ledPin = 13;    // Pin connected to an LED (indicates process status)

void setup() {
  pinMode(buttonPin, INPUT_PULLUP); // Set button pin as input with internal pull-up
  pinMode(ledPin, OUTPUT);          // Set LED pin as output
  digitalWrite(ledPin, HIGH);       // Turn on LED (process running)
}

void loop() {
  int buttonState = digitalRead(buttonPin); // Read the button state

  if (buttonState == LOW) { // Button pressed (active LOW)
    digitalWrite(ledPin, LOW); // Turn off LED (process stopped)
    while (true) {
      // Stay in this loop until reset (emergency stop behavior)
    }
  }
}

Q: Can the Pushbutton STOP be used in AC circuits?
A: Yes, as long as the voltage and current ratings of the pushbutton are compatible with the AC circuit.

Q: How do I implement debouncing in software?
A: Use a delay or a state-change detection algorithm in your code to filter out rapid changes caused by mechanical bounce.

Q: Is the Pushbutton STOP waterproof?
A: Some models are waterproof or dustproof (IP-rated). Check the product specifications for details.

Q: Can I use the Pushbutton STOP to control a motor?
A: Yes, but ensure the button's current rating matches the motor's requirements. For high-power motors, use a relay or contactor.