High frequency control for rodents

Gokul.S

Introduction:

• rodents????

Effect of rodents• Affect in 3 ways 1]Eat agricultural crops, 2]Spoil and contaminate stored food, 3]Carry diseases of humans .

Pre-harvest losses account for about 5% to 10% ,because of rodents

Control measures used presently ???• Rodenticides,• Traps,• Electric fencing.

Introduction of ultrasonic sound for rodent control:Ultra sound:• The sound waves of more than 20,000Hz is called as ultrasound.• These ultrasonic sound does not interfere with other waves.• These waves cannot be heared by normal human ear .

Effect of ultrasound on rodents:• Exposure to ultrasound on rodent causes; -Congestion, -Edema, -Degeneration, -Necrosis, -Inflammation of skin etc .,

Transducers: • The instrument used to convert one form energy into another form is

called a transducerUltrasonic transducer:• The instrument used to convert electrical pulse into sound energy is

called a ultrasonic transducer.

Ultrasonic transducer:

Components of transducer:• The active element: It is a piezoelectric or ferromagnetic material converts electrical energy into ultrasonic energy. When an electric current is applied to these crystals, they change shape rapidly. The rapid shape changes, or vibrations, of the crystals produce sound waves that travel outward.

Components of transducer:• Backing: High attenuative, high density material used for the absorption of vibration inside the transducer which is caused from the back of the active element.• Wear plate: It is nothing but an element used to protect the transducer from external environment.

Rodent control system:Components:• PV Array,• Connecting cables and switches,• Transducer ,• Frequency variator,• Battery,• Invertor,• Blocking diode.

• PV array : It is the only power source for the system to run. It traps the energy from the sun rays effectively.

Transducer:• It is the ultrasonic transducer, which is the main component of the

system, producing ultrasonic sound.• It is located at the bottom of the pole so as to effectively drive off and

kill rodents. • There were 4 ultrasonic transducers kept for the production of

ultrasound in all the directions.

Ultrasonic variator:• When an animal is subjected to an environment which is not suitable

for their living, it produces natural resistant against that environment (Evolution). • Hence to avoid such situations a frequency variator is provided to

variate the frequency for every second.

Blocking diode:• It is a device used to control the flow of charge to the PV cell from the

battery.

Battery:• It is device where the solar energy absorbed is stored for further

usage. • Usually Lead-Acid batteries are employed for the storage.

Inverter: • It is used to convert the stored DC into AC supply for the effective

running of the transducer.

Power requirement of the system:• An approximate amount of needed voltage and current will be

around 9V, 300 mA, • Hence, the power will be around 2.7watts for a single transducer.

Power requirement:• No. of modules needed = 1• Battery design = 120Ah • Invertor capacity = 11 watt

Applications:• In fields ,• In godowns.

ultrasonic system in godowns:

Inference:Advantages:• Energy –Renewable,• Noise less,• Covers 2,000 sq. meter area,• Long lasting ,• Energy efficient,• No harm to humans.

Disadvantages:• High initial cost,• Difficult to predict the flaw,• Risky maintenance.

Reference:• http://pestrepellerguide.com• http://en.wikipedia.org/wiki/Radio_frequency• http://www.americanpiezo.com/standard-products/air-transducers/ultrasonic.html• http://www.bird-x.com/transonic-pro-products-71.php?page_id=192• http://www.youtube.com/watch?v=AhTXvnyK17E• http://www.ctgclean.com/single-frequency-ultrasonic-generators.php

Tan Q