# How to design for electrical connection for a food dryer

I am on this project in building food dryer to dry 2 kg fish cracker maximum per use. Based on the calculation, I only need to use power of approximately 60 watt for the heating to achieve the energy required to dry the food.

So, here is my question:

1)Is it possible to have only a 60 watt of heating element to dry 2 kg of food?

2)How can I select for a heating element? (I also use a blower fan to distribute the heat in the food dryer uniformly)

3)If I want the user can enter the temperature that they want(maximum will be 80 degree Celcius), how can I connect the heating element with the knob and Arduino? Here I also use a temperature sensor to detect the surrounding temperature inside the dryer.

I am very much a beginner and really have a difficult time in understanding the working principle of an electrical circuit with a heating element. I am aware that the principle is similar to the oven but I dont know how to improvise it since I am using a microcontroller here which I cannot find any commercialized example of such oven in in the market. I really appreciate your help or comment and thank you for helping me.

• Your 60W calculation assumes that the heat is applied to the food in such a way as to rapidly evaporate the water in it. There's no guarantee that just putting food in a warm box will dry it in 2 hours. Also, have you allowed for the air in the box becoming saturated with water? If that happens, drying will stop until someone opens the door. May 15 '18 at 12:19
• If this should be MCU-driven, you are looking for some manner of control loop. There's lots of established knowledge in temperature regulation using PID regulators, so I would go with that. You need to establish the necessary accuracy before anything else. Then pick suitable components, like a MCU with sufficient ADC and PWM resolution. I don't understand why you need an external ADC, is it a system with galvanic isolation? At any rate, Arduino is most likely unsuitable. Writing PID regulators on ancient 8 bit MCUs can be done, but it is needlessly painful. Use a 32 bit MCU instead. Feb 20 '19 at 9:13