What does a resettable fuse do?

A resettable fuse or polymeric positive temperature coefficient device (PPTC) is a passive electronic component used to protect against overcurrent faults in electronic circuits. The device is also known as a multifuse or polyfuse or polyswitch.

How do I select a resettable 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.

How does a PTC resettable fuse 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.

Can resettable fuses break?

After a number of trip-reset cycles caused by current or ambient temperature, the PPTC resettable fuse will degrade, and failures will occur.

Are resettable fuses good?

Positive temperature coefficient (PTC) thermistors – also called polymeric positive temperature coefficient devices (PPTCs) or resettable fuses – are an excellent way of achieving this type of protection.

What is hold current resettable fuse?

“Resettable Fuse” for short protection device features rapid operation to protect the circuit as an abnormal current passing through it, operating in a similar to a fuse. These products automatically return to their initial state when the overcurrent is eliminated and can be used repeatedly.

What is the voltage of PTC?

Operating voltage rating: PTC – Typically rated up to 60 V; though there are some rated for 125 V – 250 V for telecommunication applications.

How do Polyfuses work?

In a regular fuse that means so much current causes a thin wire to simply melt; in a polyfuse it means that a small piece of conductive (polymer) plastic gets so hot that suddenly its resistance increases dramatically, so that it gets hotter still, and things escalate to a point that the resistance goes so high that …