How to choose a suitable PTC heating element?

- May 06, 2020-

PTC heating elements are widely used for heating appliances and equipment, because of their self-temperature control feature. But do you know how to choose a suitable PTC heating element? The following are some tips that you can refer when you are trying to develop a PTC heating element for your new project.

  1. Normal temperature resistance should be R25

    For 110 ~ 220V voltage, R25 generally takes 100Ω ~ 10KΩ, when used for 6 ~ 24V, R25 takes 0.5 ~ 5Ω. In general, R25 is small, the initial current is large, the heat is fast, and the power is also large. But the withstand voltage capability is poor.

2. The Curie temperature TC should be moderate

Under certain conditions, increasing the TC can increase the power consumption of the heater accordingly, but the TC is too high (greater than 260 ℃), making the electrode of the PTC component easy to age, the life is significantly shortened, and With thermal breakdown. Therefore, PTC heating elements with a Curie temperature below 260 ℃ are generally selected.

3. The withstand voltage should be high: at least twice the use of voltage to prevent electrical breakdown.

4. The temperature coefficient of resistance should be greater: generally greater than 14, to ensure less affected by changes in ambient temperature.

5. The initial inrush current should be moderate: Generally, the inrush current should be less than twice the stable working current