Prototype circuit picture
Tuesday 27 December 2011
REFERENCES
1. Blogspot. (2011) “iDEa”. [Online]. Available: http://ideabel20303.blogspot.com/2011/10/electronic-animal-and-insect-repellent.html#comment-form
2. Doctronics. (2011) “555 Timer”. [Online]. Available: http://www.doctronics.co.uk/555.htm#astable
3. Electro Schematics. (2011) “Electronic Dog Repellent Project”. [Online]. Available: http://electroschematics.com/1026/dog-repellent-circuit/
4. Just Technika. (2011) “Electronic Mosquito Repellent [Circuit Diagram]”. [Online]. Available: http://justtechnika.com/articles/electronic-mosquito-repellent-circuit-diagram/
5. Simple Electronic. (2011) “Electronic Mosquito Repellent Circuit Using 555”. [Online]. Available: http://www.simple-electronics.com/2011/09/electronic-mosquito-repellent-circuit.html
CONCLUSION
Our project title is Electronic Animal and Insect Repellent project. The purpose of this project is to build a circuit or product functioned as an animal and insect repellent, such as dog, cat, mosquito and many more. The main function of this electronic repellent is that it can generate high frequency that are annoying to animal and insect depend on its type and range of frequency generated in the same time not be hear by human. We upgraded this circuit so that it will not repel one kind of insect or animal but a lot of species depends on the frequency of sound emitted. Moreover, we have modified the circuit’s voltage supply so that it can be easily used at outdoor condition.
This circuit or project can be helpful in domestic area by keeping the mosquito and other similar creatures away using a high frequency sound produced by the circuit. This repellent should be come in handy when used at outdoor condition like lake and park.
Based on the theory, a 555 Timer is needed to gain the function of generate frequency. 555 Timer acts as an Analog to Digital Converter as it can convert analog voltage signal to digital frequency signal. In Astable Multivibrator mode, it acts as an oscillator to generate clock pulse in a wide range of frequencies with enough output power to drive the IC. In order to control the frequency generated and also made the circuit functioned to generate variable frequencies, a preset resistor and variable resistor have to be included. As both resistors vary the resistance value to gain a needed frequency to be generate.
In order to success this project, we have take proper method to design and construct the circuit. We have used Livewire software simulation tool to simulate the circuit inside computer. After that, we have connected the circuit into a breadboard to test run the project before transferred the circuit to a circuit board. Finally, after test run several time, we have soldered the components followed by the arrangement of the circuit to a circuit board to finalize the prototype.
Based on the simulation, we have found that the circuit is successfully run as what we have expected base on the theory. The concept of the circuit is to generate continuous stream of rectangular pulses having a specified frequency. When 555 Timer in the astable mode, the frequency of the pulse stream depends on the values of R1, R2 and C as can be calculated using formula. Thus, when the value of R1, R2 and C are 220Ω, 6490Ω and 0.005µF, the speaker will emits a frequency of 21.85kHz as this range of frequency known to be annoying for insect like mosquitoes but totally cannot be hear by human.
However, our project is still not reach full complete functions as it can be improved. There are many ways to improve the circuit of which is to put sensor and led lights in the circuit to detect mosquitoes. So, we will be able to know when there are mosquitoes all around us. It is also able to prove that this circuit works well because if the led light does not work that means the area is safe from the mosquitoes.
In addition, we can use direct current and the battery charger circuit. Thus, this circuit can operate when blacks out because usually mosquitoes attracted to dark places and can protect humans from mosquito attack. Almost electrical equipment cannot be used when a failure so the problem is surmountable with two ways to make electricity.
Next, we can improve by enlarging the field to repel mosquitoes so we can use a circuit covering a large area. In addition, this circuit could apply to another system and it is not limited to mosquitoes only if we modified the frequency. Besides that, we also can modified the produce of sound that can easier detect any other animal not only mosquitoes such as produce the siren or yap dog sound. This method may be also applied to the circuit and it will become more useful and can make our life easier.
RESULTS AND DISCUSSION
From the simulation had been carried out using a Livewire Simulation Software Device, it shows that the circuit is functioning well as follow the Astable Mode Theorem of Analog Integrated Circuit Timer (IC Timer) 555. The concept of the circuit is to generate continuous stream of rectangular pulses having a specified frequency.
Resistor R1 is connected between VCC and the discharge pin (pin 7) and another resistor (R2) is connected between the discharge pin (pin 7), and the trigger (pin 2) and threshold (pin 6) pins that share a common node. Hence the capacitor is charged through R1 and R2, and discharged only through R2, since pin 7 has low impedance to ground during output low intervals of the cycle, therefore discharging the capacitor. In the astable mode, the frequency of the pulse stream depends on the values of R1, R2 and C:
The frequency generated from the simulation approximately the same with the frequency calculated by using the astable frequency theory.
From the theory,
According to some sources (to be confirmed) that sound at this frequency is annoying, disturbing noise for insects specially mosquitoes, and can drive them away.
From the simulation,
Where,
T = period, s
METHODOLOGY
For this project, we have chosen a circuit found from a reliable source at internet which we have modified it ourselves to be more completed with variable frequencies generated and controlled.
Electronic Animal and Insect Repellent Circuit Diagram
In order to be able to use normal 9V battery for the purpose of domestic usage of this project, we have modified the circuit by added a power supply circuit part to convert the voltage input of 9V to 5V.
The 4 main components beside 555 Timer we have chosen to use are resistor, preset resistor, variable resistor and speaker. Resistors are the most common electronic components used in any electronic circuits, electronic devices and electronic projects. Resistor limits the function of voltage across or through it. It also serves as the simplest voltage divider.
Preset resistors are used in circuits when it is necessary to alter the resistance. Dark/light and temperature sensors usually have these components as the preset resistor allows the circuit to be made more or less sensitive (they can be turned up or down - reducing or increasing resistance).
The variable resistor is a resistor with a resistance value that can be adjusted either mechanically by means of a revolving or sliding. It is also often referred to as VR. It has a resistance value which varies as choosing a fixed resistor. The types of VR are the type of potentiometer or preset.
Speaker uses a coil of wire, which acts as an electromagnet, set inside of a magnetic gap of a permanent magnet. The speaker converts the electronic frequency to sound frequency. Try to keep the frequency of the sound as high as possible. So that the annoying sound will be heard by insects only but not human because humans don’t normally hear sound of frequency higher than 20 KHz.
As for the design method, we used analysis software of Livewire to stimulate, modify and construct the schematic circuit. The purpose of using Livewire as it is easier to construct and easier to understand. Besides, it can be fully examine the relationship between the resistance and the frequency generated by the 555 Timer. Then, we test run the hardware several time by connected the circuit in a breadboard before iron soldered into a circuit board in order to complete the prototype.
The following flowchart is the process of production of Electronic Animal and Pet Repellent project from the beginning until the final production.
Monday 26 December 2011
Theory
The main theory of the electronic animal and insect repellent circuit was how it generates variable frequency and how to control the frequencies generated. In order to perform the function of this circuit fully, a 555 Timer has been used. The reason 555 Timer used in this circuit was because it can convert an analog signal input (voltage) to digital signal output (frequency), which functioned as an ADC (Analog to Digital Converter).
555 timer based circuit is a kind of voltmeter, also an analog to digital converter, which converts the analog input voltage to digital output pulses. The output pulse width is proportional to the difference between the analog input voltage and the voltage across the capacitor. It can measure from +5V to +18V. The accuracy is high in the range of 6V to 18V. The readings are about the same with the 10 bit ADC readings. The accuracy depends on only the +5V supply voltage and the microcontroller's clock frequency.
Depending to the manufacturer, a 555 could have around 20 transistors, 15 resistors and a couple of diodes.
An Astable Multivibrator is often called also oscillator. A 555 can be used to generate clock pulses in a wide range of frequencies with enough output power to drive several ICs.
The oscillation frequency is calculated with the following formula:
| F = | 1 |
| 0.67 (R1 + 2 x R2) x C |
The same circuit can be used to control DC loads such as LEDs, lamps and DC motors. The idea is to use this circuit as a PWM signal generator. To do this, you need to replace R2 with a potentiometer. By altering the potentiometer's value, this results in changing the duty cycle output. The duty cycle is calculated as follows:
D = TTOTAL / THIGH
| D = | R1 + R2 |
| R1 + 2 x R2 |
Introduction
Animal is a creature created by God on this earth. But the animals can also cause problems to our daily life. Animal which are pests such as mosquitoes, cockroaches, rats and many more causes problems where often occur in homes. Pest problems often associated with housewives of women who are always conscious of the cleanliness of the house. With another consumer indirectly therefore need to deal with this problem must be addressed immediately so that it does not persist into the worse.
When compared the general insect repellents that sold in the market, the type of insect spray pesticides works only on mosquitoes and cockroaches, while the electricity was only able to get rid of mosquitoes and flies and sometimes even ants. For all the use is not fully effective repel pests from interfering with users and housewives. The function of the electronic animal repellent is the most effective way to address this problem. This system is a type of insect repellents for the needs of each user and housewives who have problems during sleep or in any situation.
In general, animal and other living creatures have a limited hearing range, which in other word, frequency that they can be hear are limited. Similar to human, we cannot hear low frequency sound below 64 Hz and also annoyed with high frequency sound which above 23 kHz. Based on the theory, animal like mosquitoes and cockroaches will be annoyed with some high frequency sound that different compared to human.
| Species | Approximate Range (Hz) |
| human | 64-23,000 |
| dog | 67-45,000 |
| cat | 45-64,000 |
| cow | 23-35,000 |
| rat | 200-76,000 |
| mouse | 1,000-91,000 |
| bat | 2,000-110,000 |
| owl | 200-12,000 |
| chicken | 125-2,000 |
Pest repellent project that we have created is an instrument to help the consumer or housewife to repel pests more easily also save time and energy. Differ from other pest repellents, our project using high frequency sound to repel pest. For this project, we used the PIC circuit using IC that works to control the frequency .In the circuit timer IC 555 is used as an oscillator, it generates frequency of 200 HZ to 62 kHz. The working frequency of the circuit can be set by rotating preset resistor, and the speaker converts the electronic frequency to sound frequency. Try to keep the frequency of the sound as high as possible. And make sure you don’t hear the sound of this circuit by keeping it above 20 kHz, The annoying sound will be heard by insects but not by you because humans don’t normally hear sound of frequency higher than 20 kHz. Overall, the main function of our project is to generate annoying sound that is higher than the target animal and thus repel it.
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