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

Moisture detector

Extracts from this document...

Introduction

Electronics Coursework Aim: For my project I plan to build a moisture detector which can be used too see if the ground on the cricket crease is too moist or dry. It will measure the level of water in the ground and show the moisture level by lighting a different LED. So if it was a hot day with less water in the ground the moisture detector will only light up a green LED, then as the water in the ground increased another LED will light. Yellow for when the moisture level is in the middle of the scale and red for when the ground is too moist and so unsuitable to play any cricket. The first sub-system to consider is the input. I will put two contacts in my circuit so the processor can compare the resistance of the water. ...read more.

Middle

The diagram above is my preliminary investigation using LED's, by changing the 5K potentiometer the light will have more voltage or less voltage. The 100 ? resistor protects the LED, so not too much current is allowed through. By doing this preliminary investigation I knew that I could use LED's in my circuit, as I would have between 1.8V and 5V for them to run off. Secondly, I have also investigated the Op-Amp before. In a circuit with an Op-Amp (see diagram below) there are two resistors which hold the voltage for the non-inverting input (pin 3), these two stay the same. Then for the inverting input (pin 2) there is one resistor and a variable resistor, which can change the voltage allowed through it. As the voltage between the two resistors for the inverting input changes, from high to low then the output will change. ...read more.

Conclusion

Then at wetter levels more LED's will light, then when it is too wet the circuit will turn on three red LED's, warning the user. * Draw as little current as possible, less than 50mA. This will increase the amount of time the circuit can be run off a single battery. Block diagram of proposed system: The input will just be the two contacts that are put in the ground. Depending on the resistance of the water a signal is feed into the Op-Amp. Then the Op-Amp will send a high or low signal into an IC chip that will display the relevantly coloured LED. My circuit is restricted, as I could build a circuit that has an Op-Amp for each LED. But this would take too long and make fault finding extremely difficult. Only the cost is not restricting, as even if I built an Op-Amp for each it would still be very cheap to do so. Graham South Electronics - 1 - ...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. Design and Technology Project Design an Advertisement

    since I tended to get held up in certain areas of the manufacturing. Be made out of easily available, strong and easy to clean materials. All the materials my project was made out of were readily available in my school.

  2. Bicycle Alarm Project

    NOR only circuit The above circuit uses 4 two input NOR gates and 1 three input NOR gate. Two ICs would therefore be required for this circuit. For the addition of the D and E the below addition would be required to replace the "D" input.

  1. An electronics firm wishes to introduce a range burglar alarms. This coursework contains the ...

    Alpha building and testing manual and multi-meter. 10 min. None Solder the first switch components in place 10 min. Soldering iron, stand, pliers, cutters. Heat mat and solder. 5 min. None Test the correct working of the first switch 10 min. Alpha building and testing manual and multi-meter. 10 min.

  2. Review of Electronics Systems in Society

    Computers Computers have been developed much in recent years. They are now faster, smaller and have increasing amounts of memory. Their increased performance has lead to increased integration of computers in society. Computers are now so versatile that they are used in a wide variety of situations.

  1. Electronics coursework.

    Timer monostable The timer in my circuit would decide on how long the windows would stay open for sending a pulse of electricity (positive) so that for the length of time the pulses are going the sun window will be down.

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

    of zero. It is a commonly used measure of investment efficiency. The decision given from the internal rate of return is the same as the net present value (NPV). The net present value and the internal rate of return from these organizations use the incremental cash flows from each potential investment or project.

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

    Relevant Parameters: Power Supply 6v - 9v Count Capability 0 - 99 characters Pressure Sensor (Push switch) Trigger BCD Counter on every rising edge LDR Covered; Vout > 5V Lit; Vout = 0V Phototransistor Covered; Vout Lit; Vout � 6V Photo Diode Covered; Vout � 6V Lit; Vout � 0V

  2. Design and build an electrical toy for children aged 5 years and over.

    Use This will be used for the entertainment of individuals of all ages and also to entertain groups of people. Specifications * Must be battery operated. * Must be able to be operated by any average intelligence child aged seven and up.

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