Design and Performance Evaluation of an Automatic Temperature Control System in an Incubator

Abstract

This paper aimed at designing and evaluating the performance of a circuit that can be used in an egg incubator, capable of controlling and monitoring of the required temperature automatically within the range of 32 to 39 C in a chamber using nonlinear sensor with possible linearization. Monitoring of temperature can be done using different types of sensors such as infrared sensors, thermal cameras, or any other alternative temperature measurement technique. This paper considers the use of thermistor due to its ruggedness and high level of sensitivity. Thermistor is a semiconductor device which senses the temperature in the chamber and the action of its output is send to a comparator which serves as a switching device in the circuit with the help of fast action of relay. The development of embryos in an incubator is highly sensitive to the environmental temperatures, studies shows that temperature manipulations around 38 C can be appropriate for hatching. The circuit consists of different stages: Power stage, stabilizing and amplifying stage, sensing and comparing stage, switching stage and loading stage respectively. All the stages work simultaneously to control the temperature in the chamber within the hatching period of 21 days with periodic turning of eggs manually. The performance evaluation and its output response show a favorable outcome as compared to standard hatching period.