Proposal of a Unified Sensing Circuit for Different Sensor Output Types

Abstract

In recent years, the IoT of electronic devices has been rapidly progressing, and the demand for sensors used in these devices has been increasing. There are five output types of electric sensors: voltage type, current type, resistance type, capacitance type, and inductance type. Different types of output require different detection circuits. Therefore, it is necessary to use a different circuit for each type of sensor, which is a bottleneck for the price reduction. In addition, to prepare a detection circuit suitable for a particular application, it is sometimes necessary to purchase the circuit made by a specific manufacturer. In this case, the order-made circuit takes a long time to produce and needs more learning costs to train the user. This study developed a sensing system that can be used uniformly with a single circuit regardless of the type of sensor to solve these problems. In this study, sensors are divided into voltage type, current type, resistance type, capacitance type, and inductance type according to the type of electrical characteristic. The five types of sensors are automatically identified as energy conversion type or energy control type using a detection circuit. The difference between the energy conversion type and the energy control type circuit is whether the power source is AC voltage or 0[V]. In this research, the voltage type sensor and the current type sensor can be detected as the energy conversion type circuit, and resistance, capacitance, and inductance type sensors as energy control type circuits by using the same electric circuit. Thus, regardless of the sensor type, the detection circuit automatically classifies the sensor as either energy conversion type or energy control type and automatically measures all five types when a sensor is connected.