(a) An LDR is to be used as part of a mechatronics system which is being...

Transcribed Image Text:

(a) An LDR is to be used as part of a mechatronics system which is being developed using an Arduino Uno microcontroller. The data sheet of the transducer states that in darkness, its internal resistance is IMC while in a maximum brightness of 10 Lux, the resistance drops to 4000. Using this component along with a fixed 10k0 resistor, sketch a voltage divider circuit which should be built and connected to the analog input on the Arduino Uno. What voltages will be received when: i. H. The transducer is in complete darkness The transducer is in a maximum brightness of 10 Lux. (5 marks) (b) Two strain gauges are used on a cantilever bear in order to measure the strain in a simple bending problem. As show in Figure 1, a load F is applied to one end of the beam and the gauges are arranged as shown. Derive an expression for the ratio of output and input voltages if the gauges are used in a typical Wheatstone bridge, half bridge arrangement. Assume R₁ R₂ and Ry-Ra initially, before the load is applied. (10 marks) R₂ R3 Figure Q1 (b) (c) For the problem outlined in (b), describe how the ratio of output to input voltage would change if a typical full bridge arrangement was used, with two gauges on top of the beam in tension and two underneath in compression. Comment on the relative precision of the measurements between the setups in (b) and (c). (5 marks) (a) An LDR is to be used as part of a mechatronics system which is being developed using an Arduino Uno microcontroller. The data sheet of the transducer states that in darkness, its internal resistance is IMC while in a maximum brightness of 10 Lux, the resistance drops to 4000. Using this component along with a fixed 10k0 resistor, sketch a voltage divider circuit which should be built and connected to the analog input on the Arduino Uno. What voltages will be received when: i. H. The transducer is in complete darkness The transducer is in a maximum brightness of 10 Lux. (5 marks) (b) Two strain gauges are used on a cantilever bear in order to measure the strain in a simple bending problem. As show in Figure 1, a load F is applied to one end of the beam and the gauges are arranged as shown. Derive an expression for the ratio of output and input voltages if the gauges are used in a typical Wheatstone bridge, half bridge arrangement. Assume R₁ R₂ and Ry-Ra initially, before the load is applied. (10 marks) R₂ R3 Figure Q1 (b) (c) For the problem outlined in (b), describe how the ratio of output to input voltage would change if a typical full bridge arrangement was used, with two gauges on top of the beam in tension and two underneath in compression. Comment on the relative precision of the measurements between the setups in (b) and (c). (5 marks)

Answer rating: 100% (QA)

a 1 When the LDR is in complete darkness its resistance would be 1M Using a voltage divider circuit ... View the full answer