How do I choose a PTC fuse?

How do I choose a PTC fuse?

Choosing the Correct PTC Resettable Fuse

1. Determine your circuit’s parameters.
2. Select a PTC resettable fuse.
3. Compare ratings.
4. Determine time-to-trip.
5. Verify your operating temperature range.
6. Verify fuse dimensions and mounting style.

When would you use a PTC fuse?

A PTC resettable fuse is a protection device only intended to operate during overcurrent and/or overtemperature events that are not normal operation and are generally undesired conditions. They are not intended to be a switch that operates numerous times in normal operation.

How do PTC resettable fuses work?

PTC resettable fuses are a step-up from one shot fuses. When a short circuit occurs, they heat up and transition from a low resistance state to a high resistance state. Allowing them to cool down (typically by removing the power) resets them to the low resistance state.

What does PTC Fuse stand for?

Positive Temperature Coefficient

What is holding current in PTC?

Hold-current means a maximum current value which can be flowed in normal operation. And, Trip-current indicates a minimum current value which is necessary for PTC device to move to high-resistance state.

What does a PTC thermistor do?

With PTC thermistors, resistance increases as temperature rises; usually due to increased thermal lattice agitations particularly those of impurities and imperfections. PTC thermistors are commonly installed in series with a circuit, and used to protect against overcurrent conditions, as resettable fuses.

How do I check my PTC thermistor?

Testing a PTC thermistor follows all the same steps as a NTC thermistor. First check, with an ohmmeter, the thermistor without any heat applied. With a PTC thermistor at room temperature or below, the thermistor should measure a very low resistance. Now apply heat, just like before, to the thermistor’s body.