Design with Resettable Fuse PTC in Cirkit DesignerA Resettable Fuse, also known as a Polymeric Positive Temperature Coefficient (PTC) device, is a passive electronic component used to protect circuits from excessive current conditions. Unlike traditional fuses, which must be replaced after a single use, PTCs can reset themselves once the overcurrent condition is removed and the device cools down. This makes them ideal for applications where overcurrent conditions are expected to occur occasionally, such as in battery packs, power supplies, and consumer electronics.
This circuit is a basic power control system that uses a rocker switch to control the flow of 220V power through a resettable fuse and a PT100 temperature sensor. The switch allows the user to turn the power on or off, while the fuse provides overcurrent protection and the PT100 sensor can be used for temperature monitoring.
Open Project in Cirkit Designer
The circuit includes a Benedict Switch connected in series with a Fuse Holder and an SPD (Surge Protection Device). The SPD is also connected to a Ground reference. This configuration suggests that the circuit is designed to control power flow, protect against overcurrent with the fuse, and guard against voltage surges with the SPD, with a safe path to ground for surge dissipation.
Open Project in Cirkit Designer
This circuit is a temperature control system that uses a thermocouple to measure temperature and a PID controller to regulate it. The PID controller drives a solid-state relay (SSR) to control an external load, with power supplied through an AC inlet socket.
Open Project in Cirkit Designer
This circuit features an Arduino Mega 2560 microcontroller connected to a 4x4 membrane matrix keypad and a 1-channel relay module. The Arduino is programmed to interact with the keypad inputs and control the relay, which switches an AC supply connected to a PTC air heater. The purpose of the circuit is likely to allow user input via the keypad to control the heating element, potentially for a temperature regulation system.
Open Project in Cirkit Designer| Pin Number | Description |
|---|---|
| 1 | Current Input |
| 2 | Current Output |
Note: PTCs are typically two-terminal devices and can be connected in any orientation.
Identify the Correct PTC: Choose a PTC with a voltage rating above the maximum operating voltage of your circuit and a current rating that matches the normal operating current.
Circuit Placement: Connect the PTC in series with the load that needs protection. Ensure that the PTC is placed close to the power source to protect the entire circuit.
Testing: After installation, test the circuit at normal operating conditions to ensure that the PTC does not trip during regular use.
Q: Can a PTC be used multiple times? A: Yes, PTCs are designed to reset themselves after an overcurrent condition is cleared.
Q: How quickly does a PTC reset? A: The reset time can vary based on the PTC design and the ambient temperature. It can range from a few seconds to several minutes.
Q: Is there any polarity to be considered when installing a PTC? A: No, PTCs are non-polarized components and can be installed in any orientation.
Q: Can I use a PTC for AC applications? A: Yes, there are PTCs designed for AC applications. Ensure the PTC's voltage rating is suitable for the AC voltage level.
If you're using a PTC with an Arduino UNO to protect against overcurrent in an external circuit, no specific code is required for the PTC itself. However, you can monitor the state of the PTC by measuring the voltage across it with an analog input. Here's an example of how you might do that:
const int ptcPin = A0; // Analog pin connected to the PTC
void setup() {
Serial.begin(9600);
}
void loop() {
int ptcValue = analogRead(ptcPin); // Read the voltage across the PTC
float voltage = ptcValue * (5.0 / 1023.0); // Convert to voltage
Serial.print("PTC Voltage: ");
Serial.println(voltage);
// Check if the PTC has tripped (assuming a known resistance in the low state)
if (voltage < someThreshold) {
Serial.println("PTC may have tripped.");
}
delay(1000); // Wait for 1 second before reading again
}
Note: Replace someThreshold with the appropriate voltage threshold that indicates a tripped state, based on your specific PTC's resistance and the expected voltage drop.