You are a graduate engineer working for an energy company tasked with designing a sensor that...

 

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You are a graduate engineer working for an energy company tasked with designing a sensor that turns on LED street lighting in low-light conditions. This sensor must interface with the LED's direct current 24 V supply. You can use resistors (any value), variable resistors (0-100 k), and light-dependent resistors (LDR) with the following characteristics: Conditions (lux) 10,000 50 Parameter Bright Dark Pitch Black 1 Resistance (k) 0.1 10 100 (a) Describe a circuit that utilises the allocated parts to enable the LED street lighting to turn on in low-light conditions? (b) Sketch the complete circuit and indicate where the output voltage will be provided to the LED? (c) You are subsequently provided with a comparator (see Fig. 1), an operational amplifier (op-amp) used to compare a voltage to a reference voltage. When Vin > Vref, the op-amp will output a high signal (Vsupply) and when Vin < Vref the op-amp will output a low signal (Vground). Sketch how this comparator can be combined with the circuit from above to turn on an LED when the light conditions reduce below Dark? V₁ in Vrel Vsupply ground AR =GXE Ro Re 1200 Gauge factor, G 2 Strain, & (um/m) = Voutput (d) Show through calculation whether the LED is on or off in Bright, Dark, and Pitch Black conditions. (e) You are required to modify the sensing system for automatic lightning inside a refrigerator. In this instance, the LED should turn on in Bright conditions and off when Dark. Describe how the circuit can be modified to meet this objective. (f) Describe how the sensor could be dynamically adjusted to turn on and off for different light conditions without changing components. You are a graduate engineer working for an energy company tasked with designing a sensor that turns on LED street lighting in low-light conditions. This sensor must interface with the LED's direct current 24 V supply. You can use resistors (any value), variable resistors (0-100 k), and light-dependent resistors (LDR) with the following characteristics: Conditions (lux) 10,000 50 Parameter Bright Dark Pitch Black 1 Resistance (k) 0.1 10 100 (a) Describe a circuit that utilises the allocated parts to enable the LED street lighting to turn on in low-light conditions? (b) Sketch the complete circuit and indicate where the output voltage will be provided to the LED? (c) You are subsequently provided with a comparator (see Fig. 1), an operational amplifier (op-amp) used to compare a voltage to a reference voltage. When Vin > Vref, the op-amp will output a high signal (Vsupply) and when Vin < Vref the op-amp will output a low signal (Vground). Sketch how this comparator can be combined with the circuit from above to turn on an LED when the light conditions reduce below Dark? V₁ in Vrel Vsupply ground AR =GXE Ro Re 1200 Gauge factor, G 2 Strain, & (um/m) = Voutput (d) Show through calculation whether the LED is on or off in Bright, Dark, and Pitch Black conditions. (e) You are required to modify the sensing system for automatic lightning inside a refrigerator. In this instance, the LED should turn on in Bright conditions and off when Dark. Describe how the circuit can be modified to meet this objective. (f) Describe how the sensor could be dynamically adjusted to turn on and off for different light conditions without changing components.

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a A potential circuit could utilize an LDR variable resistor and divider resistors to adjust the out... View the full answer