How to Use Rocker Switch (SPST): Examples, Pinouts, and Specs

A rocker switch is a user-interface electronic component that operates as an on-off switch. The SPST (Single Pole, Single Throw) designation indicates that the switch has one input (pole) and one output (throw), making it a simple binary device that either completes or breaks a circuit. Rocker switches are commonly used in household appliances, office equipment, and industrial controls due to their ease of operation and reliability.

• Power switches for electronic devices
• Light switches
• Automotive switches (e.g., for lights or accessories)
• Control panels for machinery

• Voltage Rating: Typically ranges from 110V to 250V
• Current Rating: Often rated up to 15A or 20A
• Contact Resistance: Usually below 50 mΩ
• Insulation Resistance: Typically greater than 100 MΩ
• Dielectric Strength: Commonly around 1500VAC for 1 minute
• Operating Temperature: Ranges from -20°C to +85°C
• Mechanical Life: Can exceed 50,000 cycles
• Electrical Life: Often rated at 10,000 cycles

Note: The pin numbers are for reference and may vary based on the manufacturer's design.

1. Power Off: Ensure that the power supply to the circuit is turned off before installing the switch.
2. Wiring: Connect the line voltage wire to pin 1 and the load wire to pin 2. Ensure that the connections are secure and insulated to prevent short circuits.
3. Mounting: Install the rocker switch into the desired panel or enclosure, making sure it is firmly seated and aligned.
4. Testing: Once installed, turn on the power supply and test the switch operation. The rocker should move smoothly between the on and off positions.

• Always verify the voltage and current ratings of the switch match the requirements of your application.
• Use appropriate wire gauges to handle the expected current load.
• Ensure that the switch is accessible for operation and maintenance.
• If the switch is to be used in an environment exposed to moisture or dust, consider a switch with an appropriate IP rating for protection.

• Switch Does Not Operate: Check for loose connections or a blown fuse. Ensure that the power supply is functional.
• Intermittent Operation: Inspect for any signs of damage or wear. Replace the switch if necessary.
• Overheating: Ensure that the current rating is not exceeded. Check for short circuits or overloads in the connected load.

• Q: Can I use a rocker switch with a DC circuit?

  • A: Yes, rocker switches can be used with both AC and DC circuits, but ensure the voltage and current ratings are suitable for your DC application.

• Q: Is it possible to replace a toggle switch with a rocker switch?

  • A: Yes, as long as the rocker switch matches the electrical specifications of the toggle switch, it can be used as a replacement.

• Q: How do I know if the rocker switch is in the on or off position?

  • A: Many rocker switches have an indicator, often marked with "I" and "O" (for on and off, respectively), or they may have a built-in light to indicate the status.

If you're using a rocker switch with an Arduino UNO to control a device like an LED, here's a simple example code:

// Define the pin connected to the rocker switch
const int rockerSwitchPin = 2; 
// Define the pin connected to the LED
const int ledPin = 13; 

void setup() {
  // Set the LED pin as output
  pinMode(ledPin, OUTPUT); 
  // Set the rocker switch pin as input
  pinMode(rockerSwitchPin, INPUT); 
}

void loop() {
  // Read the state of the rocker switch
  int switchState = digitalRead(rockerSwitchPin); 

  // If the switch is in the 'on' position, turn on the LED
  if (switchState == HIGH) {
    digitalWrite(ledPin, HIGH); 
  } else {
    // If the switch is in the 'off' position, turn off the LED
    digitalWrite(ledPin, LOW); 
  }
}

Note: In this example, the rocker switch is assumed to be connected to the Arduino such that it closes the circuit when in the 'on' position, connecting the input pin to 5V. A pull-down resistor may be needed to ensure the pin reads LOW when the switch is open (off).