How to choose a suitable PTC heater element?
At present, the ptc heating elements commonly used in heaters and other thermostatic heater products are high-temperature ptc elements, and the Curie temperature is higher than 120°C. Compared with low-temperature ptc elements, there are big differences in manufacturing process and performance parameters. Good ptc characteristics are the basis for obtaining good heating performance.
Then we need to consider the parameters when selecting ptc heater elements:
(1) Room temperature resistance R25: for 110~220V voltage, R25 is generally 100Ω~10KΩ, when used for 6~24V, R25 is 0.5~5Ω. Under normal circumstances, R25 is small, the initial current is large, the heating is fast, and the power is also large. But the withstand voltage capability is poor.
(2) Curie temperature TC should be moderate: under certain conditions, increasing TC can increase the power consumption of the heater, but TC is too high (greater than 260 ℃), so that the PTC element electrode is prone to aging, significantly shortened the life, and often Accompanied by thermal breakdown. So generally choose PTC heating element with Curie temperature below 260℃.
(3) The withstand voltage should be high: at least two times the working voltage should be guaranteed to prevent electrical breakdown.
(4) The temperature coefficient of resistance should be large: generally greater than 14 to ensure that it is less affected by environmental temperature changes.
(5) The initial impulse current should be moderate: Generally, the impulse current should be less than twice the value of the stable working current.
