Design of automatic phase-controlled converter based on temperature for microwave drying system

An Overview on a Technique to Measure and Control of the Electromagnetic Radiation Inside a Microwave Oven

“…The reason for the power increase was attributed to the lack of volume of water due to the water evaporation leading to a lack in the absorbed electromagnetic energy as shown in (9). This resulted to increase in the measured power that represented the microwave power leakage as stated in (4). The measurement of leakage power for 400 ml water is less than 200 ml because the absorbed power by the amount of 400 ml water is more than 200 ml.…”

“…With unregulated temperature, the material properties can change, resulting in thermal burning and non-uniform distribution of temperature in the materials being treated. To ensure effective monitoring of the magnetron engine without material degradation, an automatic phase control on the basis of temperature measurement was proposed in [4]. The remote temperature measurement of edible materials that were heated inside microwave ovens was revealed in [23].The proposal contains a probe attached to a temperature-sensitive circuit to produce a signal linked with an electromagnetic wave transmitting circuit placed in the microwave oven for telemetric transmission of the signal to a remote receiver and coupled to a control circuit.…”

“…Such as, the problem of microwave heating for soot filter regeneration [3], which is how to differentiate if the filter is empty or full of soot because the reflection of the electromagnetic waves inside an empty closed microwave cavity is dangerous for the magnetron. The problem of fruits, vegetables [4], and seeds [5] drying by microwave heating, which is how to assess microwave power rates in microwave dryers with and without temperature regulation. Where the microwave dries the materials from inside, but the temperature sensor measures the outside surface.…”

PID-based temperature control device for electric kettle

“…if e(t) > 0 u(t) = 0 if e(t) = 0 u(t) = −1 if e(t) < 0 (5) However, for case u(t) = −1 if e(t) < 0 has no meaning in this project, thus the term is omitted from the equation. Equation (5) reflect the on-off operation of heater: when T (t) < T d (t), the heater is activated, else T (t) ≥ T d (t)), the heater is deactivated. The time taken for the controller to perform the whole instruction including on-off control algorithm is 1.10 s. The results when the device perform the on-off controller are shown in Figure 12(a) to Figure 12(c).…”

“…LM35 temperature sensor is used for temperature measurement and proportional controller is used as control algorithm to drive DC-powered lamp and DC-powered fan to control air temperature inside the case. Temperature control inside drying chamner is done by [5]. Arduino Mega 2560 microcontroller is used as a main part and MLX90614 infrared sensor is used for temperature measurement.…”