• 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. 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.

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

    Development: After I had taken the first set of results from the potential divider, I found that the sensitivity of the voltage output was not good enough. I was measuring to two decimal places and the range of results was not broad enough.

  1. For this section of coursework I decided to undertake the task of building and ...

    to make sure the Digital Voltmeter read zero before taking another temperature. I took a reading of each point three times and found an average. I did not take the readings in consecutive goes. I started with the inside of the part of the window.

  2. Using a Rotary Potentiometer to Detect the Position of a Robotic Arm

    Note, to see the mathematics involved in any of the figures I give, see the appendix at the end of this paper. The figures in brackets relates to the subsection in the appendix. In general, I have learnt that a normal rotary resistor is more than adequate for use in most robotic arms.

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

    and internal rate of return, profitability index, capital project (investment), Fisher's Separation Theorem, and mergers and acquisitions. These dilemmas are addressed in the numerous issues that occur within the Shang-wa Electronics, Lester Electronics, Transnational Electronics Corporation, and Avral Electronics. The NPV and internal rate of return addressed relate to the

  2. 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'

  1. Water level sensor

    It has to be the middle value of the resistor for my water lever sensor. So is work for my potential divider (voltage share = resistance share) because I'm using 1000ml beaker, put the water up to 1000ml and 0ml.

  2. Investigation on sensors

    The motor would produce more voltage the faster the wind speed would be. This is because the wind shall drive the motor, causing it to turn and as it shall turn it would be cutting a magnetic field. Due to the intersection wroth the magnetic field electricity is induced.

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