Signal conditioning

In electronics and signal processing, signal conditioning is the manipulation of an analog signal in such a way that it meets the requirements of the next stage for further processing. In an analog-to-digital converter (ADC) application, signal conditioning includes voltage or current limiting and anti-aliasing filtering. In control engineering applications, it is common to have a sensing stage (which consists of a sensor), a signal conditioning stage (where usually amplification of the signal is done) and a processing stage (often carried out by an ADC and a micro-controller). Operational amplifiers (op-amps) are commonly employed to carry out the amplification of the signal in the signal conditioning stage. In some transducers, signal conditioning is integrated with the sensor, for example in Hall effect sensors. In power electronics, before processing the input sensed signals by sensors like voltage sensor and current sensor, signal conditioning scales signals to level acceptable to the microprocessor. Signal inputs accepted by signal conditioners include DC voltage and current, AC voltage and current, frequency and electric charge. Sensor inputs can be accelerometer, thermocouple, thermistor, resistance thermometer, strain gauge or bridge, and LVDT or RVDT. Specialized inputs include encoder, counter or tachometer, timer or clock, relay or switch, and other specialized inputs. Outputs for signal conditioning equipment can be voltage, current, frequency, timer or counter, relay, resistance or potentiometer, and other specialized outputs. Signal conditioning can include amplification, filtering, converting, range matching, isolation and any other processes required to make sensor output suitable for processing after conditioning. Use AC coupling when the signal contains a large DC component. If you enable AC coupling, you remove the large DC offset for the input amplifier and amplify only the AC component. This configuration makes effective use of the ADC dynamic range Filtering is the most common signal conditioning function, as usually not all the signal frequency spectrum contains valid data.