• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Aim: 'Build a sensor circuit to test the proximity of an object using a light detector to detect light from a bulb reflected f

Extracts from this document...

Introduction

Aim: 'Build a sensor circuit to test the proximity of an object using a light detector to detect light from a bulb reflected from an object.' In this experiment I am going to build a sensor circuit using an LDR, I will then calibrate the sensor and use my results to test and improve the sensor circuit. The LDR works by having a very high resistance when the light intensity is low, which does not allow current to flow through the potential divider circuit. When the light intensity increases significantly, the resistance reduces dramatically and current can flow through the circuit. The resistor within a circuit can be changed to make the circuit more sensitive. The first thing I had to do was to test two different sensors to see which one had better sensitivity. ...read more.

Middle

The LDR was fixed onto a block of wood so it was level with the bulb. A wooden block was also set between the bulb and LDR to stop light being detected directly from the bulb to the LDR. A wooden board was also used as the object that I would measure the proximity of. A one metre scale was measured out and the board was moved 0.05m for each measurement from 1m down to 0.15m. The Vout was recorded at each point on the scale. The experiment was carried out in a dark room. These are diagrams for the above description: Diagram 2 Diagram 3 My final calibration results are shown in table B: Distance/m Voltage Output/V 1.00 1.77 0.95 1.74 0.90 1.76 0.85 1.75 0.80 1.82 0.75 1.80 0.70 1.85 0.65 1.86 0.60 1.93 0.55 1.98 0.50 2.08 0.45 ...read more.

Conclusion

From my data I could see that the error varies with distance. This could be because of the LDR's limited sensitivity when light is reflected from longer lengths. This means that the percentage error increases with distance. To test this systematic error, I could calibrate the sensor for longer lengths, then test it and compare the percentage error to my first results. The effective range of my sensor is around 0.15m to 0.60m. Important properties of a sensor are good sensitivity resolution, rapid response time, small random and systematic errors. A sensors response time is the time it takes a sensor to respond to a change in it's input. Random error could be caused by a fluctuation in the input or from noise generated by the sensor, these errors are always present in experimental data. Systematic errors occur due to disturbing influences usually from the environment around the sensor and are not easily detected. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Systems and Control section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Systems and Control essays

  1. Build a sensor that detects air flow using an incandescent lamp to detect the ...

    Description R1 1 100 Ohm Resistor R2 1 470 Ohm Resistor R3 1 10k Resistor R4 1 100K Potentiometer R5 1 1K Resistor C1 1 47uF Electrolytic Capacitor U1 1 78L05 Voltage Regulator U2 1 LM339 Op Amp L1 1 Incandescent lamp with glass removed D1 1 LED Most of the components which are shown in the table were order.

  2. My aim is to produce a line follower robot with a bump sensor which ...

    As I didn't have a breadboard layout I had to figure out myself where to place each component. I had to take into consideration where to place each pins of the transistor. I also had to be careful when using the soldering iron to solder on the wires to the relay.

  1. Building a Sensor to Measure Weight, using a Potential Divider and Wheatstone Bridge.

    The potential divider sensor could only measure 0.01 V for a change in weight of 800 g giving a resolution of 0.0000125 V/g, which is not accurate enough for the sensor's specification of (0.01/1) 0.01 V/g. To improve this resolution I had to determine how I could make the sensor more sensitive.

  2. The paper discusses the issues associated with the risks assessed between the organizations bidding ...

    This theorem states that the organization's investment decisions are independent of the preferences of the owners of the organization and the financing decisions. The theory expresses that the value of a capital project or an investment is independent of the mix of methods-equity, debt, and /or cash used to finance the project.

  1. Aim: Build a sensor circuit to test the proximity of an object using a ...

    setting gave the maximum sensitivity as it had the biggest output to input difference. Next, I had to build my circuits. I used a potential divider circuit for the LDR and a simple circuit for the bulb: Diagram 1 For my final circuit design I used an 'orange power pack'

  2. Water level sensor

    Because this is a potential divider (voltage share = resistance share) there is more resistance on the sensor so more energy is needed to pass the resistor therefore more voltage they get. For reading, I need to remember when I read the level of water or any liquids, I need

  1. Investigation on sensors

    The amount of internal resistance in the motor and fan: This I personally can't alter but if it can be changed then it would affect the final result, since the lower the resistance the higher the voltage. 4. The size of the fan: The bigger the fan size would be

  2. The aim of my project is to produce a working 'People Counter', which will ...

    '0' means that pin is connected to ground. '1' means that pin is connected to Vcc. a (Pin 1) b (Pin 10) c (Pin 8) d (Pin 6) e (Pin 5) f (Pin 2) g (Pin 9) 0 0 0 0 0 0 0 1 1 1 0 0 1

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work