Under constant ventilation conditions, the passing current varies with the applied voltage. The current of the heater increases rapidly, and after the peak value is reached, the current gradually decreases as the applied voltage increases. This change is consistent with the current-voltage characteristics of the PTC element. It should be pointed out that the peak current and corresponding voltage of the heater are not only related to the resistance value, geometry, electrode type and Curie temperature of the PTC element, but also related to the structure of the heater and the wind speed of the measured pair.
Under the ventilation condition, the power of PTC heater changes with the voltage. The power of the heater increases, but reaches a saturation value at a certain voltage. It can be seen that this heater maintains the characteristic that the power of the PTC material is less affected by the external voltage.
The current of the heater under constant voltage and constant ventilation conditions decreases rapidly with time and reaches a stable value in a short time. It can be seen that the heating speed of the heater is extremely fast, and because after a short period of time, the power (current) quickly reaches equilibrium, that is, the heating temperature of the heater can be quickly stabilized, which is another PTC heater. A salient feature. Obviously, the maximum current value and corresponding time, the balance current value and corresponding time. All are related to the resistance value of PTC element of heater, Curie temperature, heater structure and ventilation conditions.
After the PTC heater reaches a stable working state at a constant voltage, its power changes with the air volume, and the power of the heater increases linearly with the increase of the air volume. This characteristic is given to the performance of the heater to change its power by changing the amount of ventilation, which is very necessary in some occasions.
However, it should also be pointed out here that if the measured air volume is further increased, that is, when the heat of the heater can be taken away by the rapid cold wind, the PTC element of the heater works at a certain equilibrium state above the back temperature. The power will gradually saturate, that is, as the amount of ventilation increases, the power will not increase significantly. At this time, it shows that the thermal power of the PTC material changes little with the external environmental conditions.