Temperature control of hot bar soldering machine
The
hot bar soldering machine with fast temperature rise is not always controlled by temperature reaction, because there is a lag from heating to temperature reaction. Even if there is no lag in temperature collection, it will take time for temperature conduction from heating to temperature rise. As long as the temperature changes slowly and needs to be stable, it can only be controlled by temperature reaction when it is not changed. Otherwise, it will be difficult to control as long as the reaction lag, and the temperature will lag from implementation to reaction. The faster the speed is, the more difficult it is to control the temperature. Therefore, it is not recommended to use all reaction control.
The collection speed is usually distributed at 200ms, which is enough for flashing. Rapid temperature rise is mainly controlled by heating power. The temperature rise can not be controlled by PID (the PID should be handled by itself when it is stable). Of course, the collection speed is also beneficial immediately. Besides heating power, the temperature speed is also related to the reaction speed of the sensor. The temperature conduction speed is primarily assumed to be conducted by air, The thickness of the sensor has a great influence. Even if the air reaches 300 degrees, the sensor will lag for a period of time to reach 300 degrees. The control method must be written by yourself, and the collection speed is not too harsh.
Assuming that the heating is fast and the cooling is fast, PID adjustment is not required. When the temperature reaches, the continuous heating is disconnected. When the temperature is low, the on / off control of heating is not very good. The temperature is simple and overshoot. The heating power should be preset in advance, and the required heating power should be calculated to output this power directly. If the demand is stable, a part of it can be reserved for PID adjustment.
If the temperature is unstable, the PID can be adjusted. If the adjustment is not good, the stable time can be considered to reduce the heating power. If the heating power is too large, it is not simple and stable. There is also no external temperature impact, which is related to the working condition of the press, but the principle of temperature stability is that heating amount = heat dissipation amount, temperature. If the heating is greater than the heat dissipation, the temperature will rise. Assuming that the change of heat dissipation is not big, it can be adjusted by PID controller. Assuming that it is too big, it is necessary to assist other methods.