How to Use Mini Pushbutton Power Switch with Reverse Voltage Protection, SV: Examples, Pinouts, and Specs

The Mini Pushbutton Power Switch with Reverse Voltage Protection (Pololu #2809) is a compact and efficient electronic switch designed for easy on/off control of low-power circuits. This switch features built-in reverse voltage protection, safeguarding your circuit from accidental damage caused by incorrect power supply connections. Its small size and robust design make it ideal for a wide range of applications, including battery-powered devices, robotics, and DIY electronics projects.

• Battery-powered devices requiring a compact on/off switch
• Robotics and automation systems
• DIY electronics and prototyping
• Low-power circuits needing reverse voltage protection

The following table outlines the key technical details of the Mini Pushbutton Power Switch:

The Mini Pushbutton Power Switch has six pins, as described in the table below:

1. Power Connections:

   • Connect the positive terminal of your power source to the VIN pin.
   • Connect the negative terminal of your power source to the GND pin.
   • Connect the positive terminal of your load to the VOUT pin.
   • Ensure the negative terminal of your load is also connected to GND.

2. Control Options:

   • To toggle the switch state, connect a momentary pushbutton between the PUSHBUTTON pin and GND.
   • Alternatively, use the ON and OFF pins for direct control via a microcontroller or logic circuit.
     • Drive the ON pin high to turn the switch on.
     • Drive the OFF pin high to turn the switch off.

3. Reverse Voltage Protection:

   • The built-in reverse voltage protection ensures that the circuit remains safe even if the power supply is connected backward. No additional components are required for this protection.

• Current Limitations: Ensure that the load does not exceed the maximum continuous current rating of 6 A. Exceeding this limit may damage the switch.
• Voltage Range: Operate the switch within the specified voltage range (4.5 V to 40 V) to avoid malfunction or damage.
• Pushbutton Debouncing: If using an external pushbutton, consider adding a debounce circuit or software debounce logic to prevent unintended toggling due to mechanical noise.
• Microcontroller Integration: When connecting to a microcontroller (e.g., Arduino UNO), use logic-level signals (3.3 V or 5 V) for the ON and OFF pins.

Below is an example of how to control the Mini Pushbutton Power Switch using an Arduino UNO:

// Define pin connections for the ON and OFF control pins
const int onPin = 7;  // Connect Arduino pin 7 to the ON pin of the switch
const int offPin = 8; // Connect Arduino pin 8 to the OFF pin of the switch

void setup() {
  // Set the ON and OFF pins as outputs
  pinMode(onPin, OUTPUT);
  pinMode(offPin, OUTPUT);

  // Initially turn the switch off
  digitalWrite(onPin, LOW);
  digitalWrite(offPin, HIGH);
  delay(100); // Small delay to ensure the switch turns off
  digitalWrite(offPin, LOW);
}

void loop() {
  // Example: Turn the switch on for 5 seconds, then off for 5 seconds
  digitalWrite(onPin, HIGH); // Turn the switch on
  delay(100);                // Small delay to ensure the switch turns on
  digitalWrite(onPin, LOW);  // Reset the ON pin
  delay(5000);               // Keep the switch on for 5 seconds

  digitalWrite(offPin, HIGH); // Turn the switch off
  delay(100);                 // Small delay to ensure the switch turns off
  digitalWrite(offPin, LOW);  // Reset the OFF pin
  delay(5000);                // Keep the switch off for 5 seconds
}

1. Switch Does Not Turn On:

   • Verify that the power supply voltage is within the operating range (4.5 V to 40 V).
   • Check the connections to the VIN, VOUT, and GND pins.
   • Ensure the ON pin or PUSHBUTTON pin is being driven high correctly.

2. Switch Turns Off Unexpectedly:

   • Ensure the load current does not exceed the 6 A maximum rating.
   • Check for loose or intermittent connections in the circuit.

3. Pushbutton Does Not Work:

   • Verify that the pushbutton is properly connected between the PUSHBUTTON pin and GND.
   • Add a debounce circuit or software debounce logic if the pushbutton toggles the switch state erratically.

4. Reverse Voltage Protection Not Working:

   • Ensure the power supply is connected to the correct pins (VIN and GND).
   • Note that the reverse voltage protection only prevents damage; it does not allow the circuit to operate with reversed polarity.

Q: Can I use this switch with a 3.3 V power supply?
A: No, the minimum operating voltage is 4.5 V. Using a 3.3 V power supply will not activate the switch.

Q: Is the switch latching or momentary?
A: The switch is latching, meaning it maintains its state (on or off) until toggled again.

Q: Can I control the switch with a microcontroller?
A: Yes, the ON and OFF pins are logic-level compatible and can be controlled with a microcontroller like an Arduino.

Q: Does the switch consume power when off?
A: The switch has a very low quiescent current when off, making it suitable for battery-powered applications.