Description

Background of the invention
This Hybrid pesticide sprayer is developed from conventional Knopshake pesticides sprayer. Using this sprayer, user can spray the pesticide by using either solar energy, Electrical energy or Mechanical Energy. A solar panel for converting solar energy into electrical energy is used and then the electrical energy is stored in the attached battery. From this battery supply is taken to the motor for pumping the pesticide.

Objective of the invention

Nowadays farmers are using fuel (Petrol, Diesel and etc.) based sprayer for spraying the pesticides. The disadvantages of this type of sprayers is high running cost and producing air pollution. To overcome these disadvantages a Hybrid pesticide sprayer is disclosed for spraying pesticide by using either solar energy, Electrical energy and Mechanical Energy. A proper low voltage motor for spraying the pesticides, a low weight high efficiency solar panel are selected and an electronic charge controller for protect the battery from over charging and low voltage is incorporated.

Summary of the invention

Hybrid power sprayer is an eco-friendly sprayer. It can be operated in three modes. They are solar energy mode, Electrical energy mode and Knopshake mode. When the solar energy is available, the sprayer operates in solar energy mode. When there is an absence of solar energy, the sprayer operates in battery mode. In case both sofar and battery charge is not available, user can use the sprayer in Knopshake mode. The main Methodology used in hybrid power sprayer is solar power conversion system. Here a diaphragm pump, solar panel, voltage regulator, and battery and sprayer tank are used. The 30W Mono crystalline solar panel is used to convert solar energy to electrical energy. The unique advantages of Mono crystalline type solar panel is less weight and high efficiency. The diaphragm pump is used to spray the pesticide. The main advantages of diaphragm pump are high pressure output and reverse flow blocking capability. The reverse blocking capability is very useful for sprayer operating in Knopshake spraying mode. The battery is used to store the electrical energy. The battery can be charged either using the solar panel or domestic electrical energy. The stored electrical energy is used for running the motor. Voltage regulator helps in maintaining constant voltage to the diaphragm pump. It also helps to control the speed of the pump and also acts as a protective device for the pump. The voltage controllers are made by electronics components.

SOLAR ENERGY

Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used.

Solar powered electrical generation relies on heat engines and photovoltaic. Solar energy's uses are limited only by human ingenuity, day lighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes. To harvest the solar energy, the most common way is to use solar panels.

Solar energy refers primarily to the use of solar radiation for practical ends. However, all renewable energies, other than geothermal and tidal, derive their energy from the sun.

Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute sunlight. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favourable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.

Solar cell

A solar cell (also called photovoltaic cell or photoelectric cell) is a solid state device that converts the energy of sunlight directly into electricity by the photovoltaic effect. Assemblies of cells are used to make solar modules, also known as solar panels. The energy generated from these solar modules, referred to as solar power, is an example of solar energy.

Photovoltaic's is the field of technology and research related to the practical application of photovoltaic cells in producing electricity from light, though it is often used specifically to refer to the generation of electricity from sunlight.
Cells are described as photovoltaic cells when the light source is not necessarily sunlight. These are used for detecting light or oth§r electromagnetic radiation near the visible range, for example infrared detectors, or measurement of light intensity.

Solar panels

A solar panel (photovoltaic module or photovoltaic panel) is a packaged interconnected assembly of solar cells, also known as photovoltaic cells. The solar panel can be used as a component of a larger photovoltaic system to generate and supply electricity in commercial and residential applications.

Because a single solar panel can only produce a limited amount of power, many installations contain several panels. This is known as a photovoltaic array. A

photovoltaic installation typically includes an array of solar panels, an inverter, batteries and interconnection wiring. Photovoltaic systems are used for either on- or off-grid applications, and on spacecraft.

Solar panels use light energy (photons) from the sun to generate electricity through the photovoltaic effect. The structural (load carrying) member of a module can either be the top layer (superstrate) or the back layer (substrate). The majority of modules use wafer-based crystalline silicon cells or thin-film cells based on cadmium telluride or silicon. Crystalline silicon is a commonly used semiconductor.

In order to use the cells in practical applications, they must be:

Connected electrically to one another and to the rest of the system Protected from mechanical damage during manufacture, transport, installation and use (in particular against hail impact, wind and snow loads). This is especially important for wafer-based silicon cells which are brittle.

Protected from moisture, which corrodes metal contacts and interconnections, and for thin-film cells the transparent conductive oxide layer, thus decreasing performance and lifetime.

Most solar panels are rigid, but semi-flexible ones are available, based on thin-film cells.
Electrical connections are made in series to achieve a desired output voltage and/or in parallel to provide a desired amount of current source capability.

Separate diodes may be needed to avoid reverse currents, in case of partial or total shading, and at night. The p-n junctions of mono-crystalline silicon cells may have adequate reverse current characteristics that these are not necessary. Reverse currents are not only inefficient as they represent power losses, but they can also lead to problematic heating of shaded cells. Solar cells become less efficient at higher temperatures and so it desirable to minimize heat in the panels. Very few modules incorporate any design features to decrease temperature, but installers try to provide good ventilation behind solar panels.

Some recent solar panel designs include concentrators in which light is focused by lenses or mirrors onto an array of smaller cells. This enables the use of cells with a high cost per unit area (such as gallium arsenide) in a cost-effective way.

Depending on construction, photovoltaic panels c3n produce electricity from a range of frequencies of light, but usually cannot cover the entire solar range (specifically, ultraviolet, infrared and low or diffused light). Hence much of the incident sunlight energy is wasted by solar panels, and they can give far higher efficiencies if illuminated with monochromatic light. Therefore another design concept is to split the light into different wavelength ranges and direct the beams onto different cells tuned to those ranges. This has been projected to be capable of raising efficiency by 50%. The use of infrared photovoltaic cells has also been proposed to increase efficiencies, and perhaps produce power at night.

Sunlight conversion rates (solar panel efficiencies) can vary from 5-18% in commercial production, typically lower than the efficiencies of their cells in isolation. Panels with conversion rates around 18% are in development incorporating innovations such as power generation on the front and back sides. The Energy Density of a solar panel is the efficiency described in terms of peak power output per unit of surface area, commonly expressed in units of Watts per square foot (W/ft2). The energy density of the most efficient mass produced solar panels are over 13 W/ft2

Solar panels are a great way to reduce electricity costs and to protect the environment. They come in a lot of flavors from very high tech and expensive to very cheap. They can be silicon based and even organic. This is why a lot of people are intimidated by solar energy panels. They do not believe that they can build their own panels from scratch. Solar power is a great way to save money. Solar power is also good for the environment as it is completely clean.
Monocrystalline Solar Panels
Monocrystalline photovoltaic electric solar energy panels have been the go-to choice for many years. They are among the oldest, most efficient and most dependable ways to produce electricity from the sun.

Each module is made from a single silicon crystal, and is more efficient, though more expensive, than the newer and cheaper polycrystalline and thin-film PV panel technologies. You can typically recognize them by their colour which is typically black or iridescent blue.

Efficiency

Currently, Sun Power (USA) manufacturers the most efficient monocrystalline solar panels - with an efficiency of 22.5 percent. In June 2010 they broke the world record for commercially produced solar cells at 24.2%.

According to various researchers, it is not theoretically possible to convert more than 29 percent of the light into energy using crystalline solar cells. Realistically, the limit for a PV panel is likely closer to 24 to 25 percent because of factors like heat, said Tom Werner, the CEO of Sun Power, during a briefing with reporters in June 2010.

Benefits of Monocrystalline Solar Panels

Determining what is an advantage or a benefit is a relativistic exercise and in this case the base of reference is the other types solar panel technologies. With this caveat in mind, here are 8 good reasons why many people choose monocrystalline solar technology:

Longevity

Monocrystalline solar panels are first generation solar technology and have been around a long time, providing evidence of their durability and longevity. The technology, installation, performance issues are all understood. Several of the early modules installed in the 1970's are still producing electricity today. Single crystal panels have even withstood the rigors of space travel!

Some other solar websites suggest that single crystalline solar panels can last up to 50 years. According to solar engineers there will be a slight drop off in efficiency of around 0.5% on average per year. So although this type of solar panels can last a long time, there will come a time when the lower efficiency makes it economically desirable to replace the panels especially as the efficiency of newer panels continues to increase.

Efficiency

As already mentioned, PV panels made from monocrystalline solar cells are able to convert the highest amount of solar energy into electricity of any type of flat solar panel. Consequently, if your goal is to produce the most electricity from a specific area (e.g., on a roof) this type of panel should certainly be considered.

Consequently, Monocrystalline panels are a great choice for urban settings or where space is limited.

Lower Installation Costs

The cost of solar panels is typically around 60% of the cost of a fully installed solar power system, with installation being a significant cost component. Installation of some amorphous thin film panels actually need more mounting rails and take longer to install; adding to the overall cost of the system. Additionally, home owners have had to rip up all their thin film panels and sell those at a loss in order to boost the size of their solar power system when they switched over to monocrystalline solar cells to produce more electricity as their usage increased over the years.

In other words -- we can expect that many new technologies will be introduced in the coming years that will increase the demand for electricity ... which will push up demand, and make it ever more desirable to be able to produce your own electricity -- so why not plan ahead and produce as much as you can from the space you allocate for this purpose.

With the world rapidly moving towards renewable energy sources and with new developments in transportation, etc., we envision a time in the not-too-distant future where the type of solar array used; specifically the ability to scale up, will also factor into house price values.

More Electricity
Besides producing more electricity per sqm of installed panels, thereby improving your cash flow (from either a reduction in your electrical bill or from the sale of the electricity or in some areas both), for those who are "going green" and are concerned about the environmental impact of solar panels, monocrystalline panels reduce the amount of electricity needed from local power plants, reducing the dependence on fossil fuels. The greater benefit is a reduction in the use of limited fuel sources and greenhouse gases being pumped into the environment.

Bankability

A corollary of the durability and longevity of this type of solar panels is that in areas where there is an established track record of performance (e.g., in Germany), users are able to obtain bank financing of up to 90% for our projects, which is certainly a big reason why Germany has the largest installed base of solar panels in the world.

Photovoltaic Module
High Efficiency Back-Contact Solar Modules Photovoltaic modules made with unique back connected cells.
Cells with high conversion efficiency up to 20%.
Black modules available on request.
Also available in various frame colours.
Design to charge 12 to 48 V batteries for off-grid remote systems.
Made with high quality materials to ensure high reliability of modules.

15W Monocrystalline
Photovoltaic Module.
Max Power (Pm) 15W.
Voltage at Max Power (Vmp) 17.1V.

• . Current at Max Power (Imp) 0.88A.
Open Circuit Voltage (Voc) 21.5V.
Short Circuit Current (Isc) 0.98A.
Max Power Tolerance ±10%
Nominal Operating Cell Temp. -45°C to +85°C .
Maximum System Voltage 600V.

How do Solar Panels Work?

Whether on a solar-powered calculator or an international space station, solar panels generate electricity using the same principles of electronics as chemical batteries or standard electrical outlets. With solar panels, it's all about the free flow of electrons through a circuit.

To understand how solar panels generate electrical power, it might help to take a quick trip back to high school chemistry class. The basic element of solar panels is the same element that helped create the computer revolution - pure silicon.

When silicon is stripped of all impurities, it makes an ideal neutral platform for the transmission of electrons. Silicon also has some atomic-level properties which make it even more attractive for the creation of solar panels.

Silicon atoms have room for eight electrons in their outer bands, but only carry four in their natural state. This means there is room for four more electrons. If one silicon atom contacts another silicon atom, each receives the other atom's four electrons. This creates a strong bond, but there is no positive or negative charge because the eight electrons satisfy the atoms' needs. Silicon atoms can combine for years to result in a large piece of pure silicon. This material is used to form the plates of solar panels.

Here's where science enters the picture. Two plates of pure silicon would not generate electricity in solar panels, because they have no positive or negative charge. Solar panels are created by combining silicon with other elements that do have positive or negative charges.

Phosphorus, for example, has five electrons to offer to other atoms. If silicon and phosphorus are combined chemically, the result is a stable eight electrons with an additional free electron along for the ride. It can't leave, because it is bonded to the other phosphorus atoms, but it isn't needed by the silicon. Therefore, this new silicon/phosphorus plate is considered to be negatively charged.
In order for electricity to flow, a positive charge must also be created. This is achieved in solar panels by combining silicon with an element such as boron, which only has three electrons to offer. A silicon/boron plate still has one spot left for another electron. This means the plate has a positive charge. The two plates are sandwiched together in solar panels, with conductive wires running between them.

With the two plates in place, it's now time to bring in the 'solar' aspect of solar panels. Natural sunlight sends out many different particles of energy, but the one we're most interested in is called a photon. A photon essentially acts like a moving hammer. When the negative plates of solar cells are pointed at a proper angle to the sun, photons bombard the silicon/phosphorus atoms.

Eventually, the 9th electron, which wants to be free anyway, is knocked off the outer ring. This electron doesn't remain free for long, since the positive silicon/boron plate draws it into the open spot on its own outer band. As the sun's photons break off more electrons, electricity is generated. The electricity generated by one solar cell is not very impressive, but when all of the conductive wires draw the free electrons away from the plates, there is enough electricity to power low amperage motors or other electronics. Whatever electrons are not used or lost to the air are returned to the negative plate and the entire process begins again.

DIAPHRAGM PUMP

A diaphragm pump is a positive displacement pump that uses a combination of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable non-return check valves to pump a fluid. Sometimes this type of pump is also called a membrane pump.

There are three main types of diaphragm pumps:

Those in which the diaphragm is sealed with one side in the fluid to be pumped, and the other in air or hydraulic fluid. The diaphragm is flexed, causing the volume of the pump chamber to increase and decrease. A pair of non-return check valves prevents reverse flow of the fluid.

Those employing volumetric positive displacement where the prime mover of the diaphragm is electro-mechanical, working through a crank or geared motor drive. This method flexes the diaphragm through simple mechanical action, and one side of the diaphragm is open to air.
Those employing one or more unsealed diaphragms with the fluid to be pumped on both sides. The diaphragm(s) again are flexed, causing the volume to change.

When the volume of a chamber of either type of pump is increased (the diaphragm moving up), the pressure decreases, and fluid is drawn into the chamber. When the chamber pressure later increases from decreased volume (the diaphragm moving down), the fluid previously drawn in is forced out. Finally, the diaphragm moving up once again draws fluid into the chamber, completing the cycle. This action is similar to that of the cylinder in an internal combustion engine.

Characteristics of Diaphragm pumps:

Have good suction lift characteristics, some are low pressure pumps with low flow rates; others are capable of higher flows rates, dependent on the effective working diameter of the diaphragm and its stroke length. They can handle sludge's and slurries with a relatively high amount of grit and solid content.

Have good dry running characteristics.
Are used to make air pumps for the filters on small fish tanks.
Can be up to 97% efficient.
Have good self-priming capabilities.
Can handle highly viscous liquids.

Are available for industrial, chemical and hygienic applications cause a pulsating flow that may cause water hammer Mini diaphragm pumps operate using two opposing floating discs with seats that respond to the diaphragm motion. This process results in a quiet and reliable pumping action. Higher efficiency of the pump is evident in the longer life of the motor pump unit.

These DC motor diaphragm pumps have excellent self-priming capability and can be run dry without damage. Rated to 160 Deg. F (70 Deg. C).

No metal parts come in contact with materials being pumped; diaphragms and check valves are available in Viton, Santoprene or Buna-N construction. So these mini diaphragm pumps are chemically resistant.
Mini diaphragm pumps prime within seconds of turning the pump on; prime is maintained by two check valves (one on either side). Separated from the motor, the pump body contains no machinery parts, so pump can be in dry running condition for a short while.
A built-in pressure switch inside the pump can automatically stop the pump, when the pressure reach a setting data.

Ultra Compact diaphragm pump uses unique Duplex design to deliver flow and pressure comparable to much larger pumps. Suitable for water and light water based chemicals. Pumps can be situated above water level

Self Priming up to 0.75m
Maximum liquid temperature 43"C
Built-in thermal overload protection
Low amp draw for battery powered applications
Pressure switch control for automatic on/off if required
Built in backflow preventer

VOLTAGE REGULATOR

A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. A voltage regulator may be a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.

Electronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements. In automobile alternators and central power station generator plants, voltage regulators control the output of the plant. In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line. A voltage regulator is a switching power supply that supplies a steady, typically low, voltage to a load. Voltage regulators, such as DC to DC converters, are used to provide stable voltage sources for electronic systems. Voltage regulators regulate the external power supplied to the internal circuitry so that the current usage or quiescent power is efficient. Typically, a voltage regulator is used for supplying an output voltage with a regulated voltage level from a DC voltage source by appropriately controlling a duty cycle of a power switch transistor. Switching voltage regulators are known to be an efficient type of DC to DC converter.

A switching regulator generates an output voltage by converting an input DC voltage into a high frequency voltage, and filtering the high frequency voltage to generate the output DC voltage. A voltage regulator maintains a level output voltage despite variations in power supply voltage or current drawn by a load. These regulators typically output a relatively high voltage. The high voltage regulators use a transformer or possibly another similar device to increase the supply voltage to the desired high voltage for driving the load. Applications of these high voltage regulators include charging a photoflash capacitor, such as those commonly used in cameras. Low dropout voltage regulators are widely used building blocks in almost any electronic products.

Temperature coefficient of the output voltage is the change in output voltage with temperature {perhaps averaged over a given temperature range), while...

Initial accuracy of a voltage regulator (or simply "the voltage accuracy") reflects the error in output voltage for a fixed regulator without taking into account temperature or aging effects on output accuracy.

Dropout voltage is the minimum difference between input voltage and output voltage for which the regulator can still supply the specified current. A Low Drop-Out (LDO) regulator is designed to work well even with an input supply only a Volt or so above the output voltage.

Electronic voltage regulators

A simple voltage regulator can be made from a resistor in series with a diode (or series of diodes). Due to the logarithmic shape of diode V-l curves, the voltage across the diode changes only slightly due to changes in current drawn. When precise voltage control is not important, this design may work fine.

Feedback voltage regulators operate by comparing the actual output voltage to some fixed reference voltage. Any difference is amplified and used to control the regulation element in such a way as to reduce the voltage error. This forms a negative feedback control loop; increasing the open-loop gain tends to increase regulation accuracy but reduce stability (avoidance of oscillation, or ringing during step changes). There will also be a trade-off between stability and the speed of the response to changes. If the output voltage is too low (perhaps due to input voltage reducing or load current increasing), the regulation element is commanded, up to a point, to produce a higher output voltage-by dropping less of the input voltage (for linear series regulators and buck switching regulators), or to draw input current for longer periods (boost-type switching regulators); if the output voltage is too high, the regulation element will normally be commanded to produce a lower voltage.

However, many regulators have over-current protection, so that they will entirely stop sourcing current (or limit the current in some way) if the output current is too high, and some regulators may also shut down if the input voltage is outside a given range.

DC-to-DC converter

A DC-to-DC converter is an electronic circuit which converts a source of direct current (DC) from one voltage level to another. It is a class of power converter.

Linear regulators can only output at lower voltages from the input. They are very inefficient when the voltage drop is large and the current is high as they dissipate heat equal to the product of the output current and the voltage drop; consequently they are not normally used for large-drop high-current applications.

The inefficiency wastes power and requires higher-rated, and consequently more expensive and larger, components. The heat dissipated by high-power supplies is a problem in itself as it must be removed from the circuitry to prevent unacceptable temperature rises.

They are practical if the current is low, the power dissipated being small, although it may still be a large fraction of the total power consumed. They are often used as part of a simple regulated power supply for higher currents: a transformer generates a voltage which, when rectified, is a little higher than that needed to bias the linear regulator. The linear regulator drops the excess voltage, reducing hum-generating ripple current and providing a constant output voltage independent of normal fluctuations of the unregulated input voltage from the transformer/bridge rectifier circuit and of the load current.

Linear regulators are inexpensive, reliable if good heat sinking is used and much simpler than switching regulators. As part of a power supply they may require a transformer, which is larger for a given power level than that required by a switch-mode power supply. Linear regulators can provide a very low-noise output voltage, and are very suitable for powering noise-sensitive low-power analog and radio frequency circuits. A popular design approach is to use an LDO, Low Drop-out Regulator that provides a local "point of load" DC supply to a low power circuit.

DC MOTOR SPEED CONTROL

This DC Motor speed control circuit uses pulse width modulation to | control the speed of the motor.

The potentiometer controls the width of the pulses to control the speed of the motor or train engine. The Pot can be mounted remotely on a control panel of in a FB enclosure to make a hand held throttle.

Power supply: 12V. (Can also be used with voltages as low as 5 VDC) 1.5 Amp max current Perfect for making a hand held throttle for model railroad switch where extremely slow motion is required. With a little modification, it will fit into the FB02 box and make

The purpose of a motor speed controller is to take a signal representing the demanded speed, and to drive a motor at that speed. The controller may or may not actually measure the speed of the motor. If it does, it is called a Feedback Speed Controller or Closed Loop Speed Controller, if not it is called an Open Loop Speed Controller. Feedback speed control is better, but more complicated, and may not be required for a simple robot design.

Motors come in a variety of forms, and the speed controller's motor drive output will be different dependent on these forms. The speed controller presented here is designed to drive a simple cheap starter motor from a car, which can be purchased from any scrap yard. These motors are generally series wound, which means to reverse them, they must be altered slightly.

Theory of DC motor speed control

The speed of a DC motor is directly proportional to the supply voltage, so if we reduce the supply voltage from 12 Volts to 6 Volts, the motor will run at half the speed. How can this be achieved when the battery is fixed at 12 Volts?
The speed controller works by varying the average voltage sent to the motor. It could do this by simply adjusting the voltage sent to the motor, but this is quite inefficient to do. A better way is to switch the motor's supply on and off very quickly. If the switching is fast enough, the motor doesn't notice it, it only notices the average effect.

When you watch a film in the cinema, or the television, what you are actually seeing is a series of fixed pictures, which change rapidly enough that your eyes just see the average effect - movement. Your brain fills in the gaps to give an average effect.

Now imagine a light bulb with a switch. When you close the switch, the bulb goes on and is at full brightness, say 100 Watts. When you open the switch it goes off (0 Watts). Now if you close the switch for a fraction of a second, then open it for the same amount of time, the filament won't have time to cool down and heat up, and you will just get an average glow of 50 Watts. This is how lamp dimmers work, and the same principle is used by speed controllers to drive a motor. When the switch is closed, the motor sees 12 Volts, and when it is open it sees 0 Volts. If the switch is open for the same amount of time as it is closed, the motor will see an average of 6 Volts, and will run more slowly accordingly.

As the amount of time that the voltage is on increases compared with the amount of time that it is off, the average speed of the motor increases.

This on-off switching is performed by power MOSFETs. A MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) is a device that can turn very large currents on and off under the control of a low signal level voltager

The time that it takes a motor to speed up and slow down under switching conditions is dependent on the inertia of the rotor (basically how heavy it is), and how much friction and load torque there is. Fig 7 shows the speed of a motor that is being turned on and off fairly slowly:

We can see that the average speed is around 150, although it varies quite a bit. If the supply voltage is switched fast enough, it won't have time to change speed much, and the speed will be quite steady. This is the principle of switch mode speed control. Thus the speed is set by PWM - Pulse Width Modulation.

As the load torque increases, the speed drops - we are following the line in the torque speed characteristic from the left hand side towards the right, drooping down. This is the same as the uncontrolled motor. The motor torque always equals the load torque when the motor is running at constant speed (this follows from Newton's first law - "An object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force." The motor torque and load torque must be balanced out if the speed is not changing).

Let's call the current limit value iL and the equivalent torque value on the torque-current graph at this current is TL When the load torque exceeds TL, the motor can no longer create an equal and opposite torque, and so the load will push the motor backwards in the opposite direction - we are now following the line as it drops downwards into negative speed.

Let's take an example; an opponent's robot is more powerful than ours (or his current limit is set higher), and we are in a pushing match. As each pushes harder, our speed controller reaches its current limit first. Our robot is now pushing at a constant force (since the motor torque is now constant at its highest value). As the opponent pushes harder, our wheels start to rotate backwards, and the pair of robots accelerates backwards at a rate given by Newton's second law:

BATTERY

This powerful little battery pack is very flexible; it can act as a 5 volt battery or a 19 volt battery with 6 steps in between. Outputs at 5V, 6V, 7.5V, 9V, 12V, 14V, 16V and 19V. It can also be charged with voltages as low as 5 volts and ashighas24VDC

This battery pack consists of a 44 watt hour lithium ion battery assembly and three DC/DC converters. The first DC converter allows the pack to be charged with a wide range of voltage inputs. The second allows the pack to deliver a user settable voltage to run equipment requiring 5volts to 19+volts. The third DC converter supplies a steady 5 volts to a USB port for charging cell phones, Ipods, and other USB charged equipment. All this is built into the sleek black battery case.

Special Features:

44 Watt-Hour battery pack with flexible output voltage (upgradeable to 88 watts).
Automatic overcharge protection
Gas gauge feature tells how much power is remaining
Highly regulated voltage source, doesn't sag like batteries do.
Auxiliary 5 volt USB output for charging cell phones.

Locking feature prevents the voltage from changing by mistake.

The PST-MP3500 portable rechargeable battery is designed to charge while running your equipment, just plug the charger into the PST-MP3500 and the battery pack into the laptop computer.

The charger section of the battery pack has a DC/DC converter with a wide input range. This means that the pack can be charged from a wide variety of sources. The input voltage for charging can be as low as 5 volts and as high as 24 volts. This makes the PST-MP3500 perfect for energy harvesting type charging from (for example) unregulated solar panels as long as the input voltage doesn't go above 24 volts.

Use it for a laptop today, a digital camera tomorrow, or a portable battery for a DVD while simultaneously charging your cell phone--it is very flexible.

• For safety reasons this unit will reset the voltage to 5 volts when the
barrel connector is changed, the cord is removed, or the unit shuts itself off when the battery is fully discharged. Just press the button until the desired voltage appears.

Objective of the invention

The main application of the hybrid pesticide sprayer will save the money to the farmer. Further Air pollution and Noise pollution is reduced. Another objective of the invention is to save time and the Hybrid pesticide sprayer will require very less maintenance. Another objective of the invention is to provide a pesticide sprayer that is lesser in weight as compared to a conventional pesticide sprayer, thereby enabling the user to carry it easily. Yet another objective of the invention is to provide a Hybrid pesticide sprayer is to provide a highly reliable and efficient device as compared to the conventional pesticide sprayer.

Conclusion

The Hybrid Pesticide Sprayer is more useful for industrial, chemical, agriculture and hygienic applications. The Hybrid pesticide sprayer may be used in three modes of solar energy, electrical energy and Knopshake mode. A diaphragm motor pump is used to spray the pesticide. In Knopshake mode human power is used to spray the pesticide. When using manual method there is no reverse flow of contents in the sprayer since diaphragm pump consist of a Non Return Valve.

Specially designed electronics circuit is used to control the flow of pesticide and protect battery from over charge and under charge.

Description of Drawings
Fig. 1 : Block Diagram of the Proposed System
Fig. 2 : Diagram of Diaphragm Pump
Fig. 3 : Rear View of Hybrid Pesticide Sprayer
Fig. 4 : Side view of Hybrid Pesticide Sprayer
Fig. 5 : Block diagram of Diaphragm pump
Fig.6 : Block diagram of speed controller
Fig. 7 : Speed of motor and supply voltage
Fig.8 : Torque speed during current limiting

CLAIMS

We Claim :

A Hybrid Pesticide Sprayer that can be operated by solar energy, electrical energy or mechanical energy, comprising a diaphragm pump, solar panel, battery, low voltage motor, voltage regulator and sprayer tank.

The invention as claimed in claim 1, wherein a Mono crystalline solar panel converts the solar energy to electrical energy thereby charging the battery.

The invention as claimed in claim 1, wherein the hybrid pesticide sprayer uses a low voltage motor for spraying the pesticide thereby reducing the weight of the device.

The invention as claimed in claim 1, wherein there is no reverse flow of -contents in the sprayer since diaphragm pump consist of a Non Return Valve.