How to Use PTC 100W: Examples, Pinouts, and Specs

The PTC 100W is a Positive Temperature Coefficient (PTC) thermistor with a power rating of 100 watts. This component is primarily used for overcurrent protection and temperature sensing applications. When the temperature increases, the resistance of the PTC thermistor also increases, which helps in limiting the current flow and protecting the circuit from damage.

• Overcurrent Protection: Automatically limits the current in a circuit when the temperature rises beyond a certain threshold.
• Temperature Sensing: Used in various applications to monitor and control temperature.
• Heaters: Employed in heating elements where a self-regulating temperature is required.
• Power Supplies: Protects power supplies from overcurrent conditions.

1. Identify the Pins: Ensure you correctly identify the pins (A and B) of the PTC 100W thermistor.
2. Connect to Power Supply: Connect pin A to the positive voltage supply.
3. Connect to Load: Connect pin B to the load or ground, depending on your circuit design.
4. Verify Connections: Double-check all connections to ensure they are secure and correct.

• Heat Dissipation: Ensure adequate heat dissipation to prevent overheating.
• Voltage Rating: Do not exceed the maximum voltage rating of 250V.
• Current Rating: Ensure the current does not exceed the trip current of 2A.
• Environmental Conditions: Operate within the specified temperature range (-40°C to 125°C).

Below is an example of how to use the PTC 100W thermistor with an Arduino UNO for temperature sensing:

const int thermistorPin = A0; // Analog pin connected to the thermistor
const float baselineTemp = 25.0; // Baseline temperature for reference

void setup() {
  Serial.begin(9600); // Initialize serial communication
  pinMode(thermistorPin, INPUT); // Set thermistor pin as input
}

void loop() {
  int sensorValue = analogRead(thermistorPin); // Read the analog value
  float voltage = sensorValue * (5.0 / 1023.0); // Convert to voltage
  float resistance = (5.0 - voltage) * 10000 / voltage; // Calculate resistance
  float temperature = baselineTemp + (resistance - 10000) / 100; // Estimate temperature

  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");

  delay(1000); // Wait for 1 second before next reading
}

1. Incorrect Readings:

   • Solution: Ensure all connections are secure and correct. Verify the power supply voltage.

2. Overheating:

   • Solution: Check for adequate heat dissipation. Ensure the current does not exceed the trip current.

3. No Response:

   • Solution: Verify the component is within the operating temperature range. Check for any physical damage.

• Double-Check Connections: Ensure all connections are correct and secure.
• Use Proper Heat Sinks: If the component is overheating, use appropriate heat sinks or cooling mechanisms.
• Verify Power Supply: Ensure the power supply voltage and current are within the specified limits.
• Check for Damage: Inspect the component for any physical damage or signs of wear.

By following this documentation, users can effectively utilize the PTC 100W thermistor in their electronic projects, ensuring reliable performance and protection.