연세댿� 전기전자 기초실험 chapter. 5 (2017년판) 예렙+결렙

1. Text
1-1. Experimental Result
In this experiment, we designed ‘Fan system’ with Wheatstone bridge containing adjustable resistor, operational amplifier, DC motor and 5-level LEDs. Centerd on Arduino, the Wheatstone bridge and op amp correspond to the input stage while the DC motor and the 5-level LED correspond to the output stage. First, we designed Wheatstone bridge which consists of 4 regular resistor and 1 adjustable resistor. By using adjustable resistor, we were able to generate a voltage that could have a specific range of values ​​rather than a fixed value. The next step was to amplify the voltage from the Wheatstone bridge using the Op Amp. In this stage we can get voltage which have range enough to be sensed and distinguished by Arduino. Arduino is sensing output voltage of Op Amp as analog input and generate digital output voltage depending on input values. Finally we were able to control 5-level DC motor and LEDs through Arduino digital output voltage. [Figure. 1] show the overall circuit of ‘Fan system’