Nowadays, farmers in the agriculture field facing a lot of problems in pouring the water into their field to keep their crops green especially in summer season. It’s because they don’t have a proper idea about the power availability. Even it is available, they have to wait until the field is properly watered. Thus, this procedure checks them to stop doing other acts. But, there is a solution, namely “solar powered auto irrigation system”.In the trial of solar power based irrigation system, PV cells are used to produce electricity, that energy is stored in rechargeable batteries.The energy which is produced from the batteries is used for the system operation. A water pump is used to pump the water from a boor well to a water storage tank. This article discusses solar powered irrigation system using solar energy.
This article is a collection of electronics kits for beginners, which can be used as simple projects for engineering students. The following projects can also be used for your beginner, hobbyists.or mini project needs. But, we won’t recommend these projects for your final year project requirements. While choosing the projects, you have to take care with popular circuits which are easy to implement. The logic behind learning electronics for beginners or choosing beginner Btech projects is simple; We advise you go through all the following projects which are practically tested and that will save you a lot of time for troubleshooting. All of these projects fall into the category of beginner, small or hobby and that’s why we used simple electronics for beginners as a title. And you can experiment all these circuits at your own free will and creativity.
The term TFET stands for tunneling field effect transistor, that has been developed in the year 1992 by T. Baba, as one of the capable changes to the conventional MOSFET’s based on numerous performance factors includes Possible for above the 60mV/decade, sub threshold swing, ultra-low power & ultra-low voltage, the effects of short channel, leakage current reduction, speed requirement exceeding due to the effects of tunneling, capability to work on sub-threshold and super-threshold voltage, similarity in the assembly process as equated with a MOSFET. Taking into attention the above factors, the MOSFET could be changed by a potential substitute in terms of tunneling field effect transistor for the purpose of high-speed, energy efficient , and ultra-low power applications in the area of integrated circuits.
Thermal imaging device is a benefit to the armed forces like navy, army and air force because of its 24 hours working capability to perform well in all climate conditions. Thermal detectors capture the IR(Infrared) radiation produced by all objects above complete zero temperature. The temperature differences of the captured section are denoted as a hectogram. With the beginning of IR detector technology, the large cooled thermal detectors having moving parts and difficult cryogenic temperatures have changed into small, and less expensive uncooled microbolometers having no moving parts. Thermal imaging system due to its numerous advantages has various applications in the military and also defines.
It is widely used by the armed forces for border surveillance and law implementation. It is also used in ship accident avoidance and control systems. In the aviation industry, it seriously mitigates the dangers of flying in the night conditions. They are widely used in military flight to recognize, find and aim the enemy forces. Recently, they are also being merged in civil aviation for health checking of aircraft.
In this article, let us discuss the circuit for recharging the Lead Acid battery using the Solar panel. The concept of solar is not new for us. As day by day, non-renewable energy sources are reducing, and the usage of solar energy is improved. This energy is not only used on the Globe, but also used in space stations where no electrical power is accessible. Here is the simple circuit to charge a rechargeable Lead-acid battery (12V, 1.3Ah) from the solar panel. This solar charger has regulation of current, voltage and also has over-voltage cut off services. This circuit may also be used to charge the Lead-acid battery at constant voltage because o/p voltage is variable.
The transformer is a static device that changes electrical energy from one circuit to another circuit with the help of mutual induction (without any connection) between two windings namely primary winding and secondary winding. It changes power from one circuit to another circuit without altering its frequency, but may be on changing voltage level. This is the simple definition of transformer. This article discusses what is transformer, basic theory and why this only works with AC.
In the year 1997, the electronic eye security system was found and base of processes in New Delhi. There are different organizations under these systems,such as electronic eye Pvt.Ltd, IIST (Indian institute of science and technology), electronic eye systems, and Mahamahi Exims. The electronic eye security system creates an entire collection of surveillance products and high-tech security. These Systems work on the integration of system and project execution at the customers place for numerous surveillance products.The electronic eye security systems which are available in the market are expensive, and programming is very problematic for a microcontroller based system. Here is a simple and inexpensive electronic eye security system that you can build easily.
Photo-sensing (LM393) based Electronic Eye Security System
The main goal of this project is to design an electronic security system based on a photo-sensing arrangement. It uses a double comparator LM393 that is extensively used in several profitable applications. Here, it is used to detect the input signal through a LDR (light-dependent resistor). The output of the comparator drives a relay and a buzzer. This concept is very beneficial as a burglar warning in public places such as banks, hotels jewelry stores, malls, and homes.
What is LM393?
The LM393 is a dual independent precision voltage comparator accomplished by single or split supply process. These devices are intended to let a common mode range-to-ground level with the only supply operation. Input offset voltage conditions as low as 2.0 mV make this device a superb collection of several applications in buyer automotive and industrial electronics. The features of LM393 include the following.
- Single supply ranges from 2.0 Vdc to 36 Vdc
- Split Supply Range: +/-1.0 Vdc to +/-18 Vdc
- Low Current Drain Independent of Supply Voltage: 0.4 mA
- Low i/p Bias Current is 25 nA
- Low i/p Offset Current: 5.0 nA
- Power Supply Voltage and differential i/p voltage range both are equal
- O/p voltage is compatible with ECL, DTL, MOS, TTL, and CMOS Logic Levels
- ESD locks on the i/ps
- ESD Locks on the i/ps increase the roughness of the device without disturbing performance
Circuit and Working of the Electronic Eye Security System
The circuit diagram of an electronic eye security system using LM393 is shown below. The following circuit is built with various electrical and electronic components like around 12V-0-12V, X1-(750mA secondary transformer), 1N4007 rectifier diodes (D1 through D3), LDR , C1 and C2 filter capacitors, 5V IC17805 voltage regulator, IC2 (dual comparator LM393), 12V PZ- (multi-tone high-gain buzzer), T1 transistor for driving PZ1, T2 transistor BC547 for driving 12V, relay (1C/O) for controlling a bulb (B1), and 10-kilo-ohm potentiometer VR1.
When the light drops on light dependent resistor (LDR1), its resistance extremely falls, which leads to activating an alarm to alert the user.The proposed system is appropriate for locking lockers, cash boxer, etc. This circuit is located in the locker or cash box in such a way that, when the robber opens it and uses a torch light to discover the valuables, light falls on light dependent resistor (LDR1), which performs as an electronic eye.
The signal o/p from the light dependent resistor (LDR1) is fed to IC2. The o/p from IC2 triggers the alarm when light falls on light dependent resistor during a robbery attempt.Similarly, bulb-B1 glows as a visual aware to prevent the burglary attempt.
If the reference voltage at pin-3 of IC2 is less than sensor voltage at pin -2 of IC2, o/p goes low routinely. This specifies that no light is dipping on the light dependent resistor. Low o/p of IC2 is fed to T1&T2. As a result, both are in cutoff state, so no flow of current through the beeper, keeping it in silent mode. Likewise, no flow of current in the relay, and so bulb B1 do not glow.
If the reference voltage at pin-3 of IC2 is superior than sensor voltage at pin-2 of IC2, o/p goes high automatically. This indicates that light is falling on LDR1. High o/p of IC2 is fed to T1 and T2. As a result, both transistors are in on (active) state. The flow of current through the buzzer & relay. The buzzer generates a loud alarm to alert you or people around you and, at the same time, bulb B1 glows as the circuit finishes through relay RL1’s contacts.
Operation of Electronic Eye Security System
- Initially, connect the circuit of the electronic eye security system as shown in the above circuit diagram on the bread board.
- Now connect the battery for the supply voltage of 9v.
- Place the LDR (Light Dependent Resistor) in the light.You can detect no sound is generated from the buzzer.
- Place the light dependent resistor in the dark, then the buzzer starts buzzing. Light emitting diode connected to the buzzer also starts flashing.
- As the light intensity dropping on the LDR growths sound generated by the buzzer increases.
Applications of Electronic Eye Security System
- This system can be used in door bell circuits.
- This can be used in a garage door opening and closing circuits.
- This system can be used in security applications.
Thus, this is all about electronic eye security system using photo-sensing (LM393). We hope that you have got a better understanding of this concept.Furthermore, any doubts regarding this concept or to implement any electrical and electronic projects, please give your valuable suggestions by commenting in the comment section below. Here is a question for you, What is the function of LM393?
The Power MOSFET is a type of MOSFET. The operating principle of power MOSFET is similar to the general MOSFET. The power MOSFETS are very special to handle the high level of powers. It shows the high switching speed and by comparing with the normal MOSFET, the power MOSFET will work better. The power MOSFETs is widely used in the n-channel enhancement mode, p-channel enhancement mode, and in the nature of n-channel depletion mode. Here we have explained about the N-channel power MOSFET. The design of power MOSFET was made by using the CMOS technology and also used for development of manufacturing the integrated circuits in the 1970s.
What is a Power MOSFET?
A power MOSFET is a special type of metal oxide semiconductor field effect transistor. It is specially designed to handle high-level powers. The power MOSFET’s are constructed in a V configuration. Therefore, it is also called as V-MOSFET, VFET. The symbols of N- channel & P- channel power MOSFET are shown in the below figure.
Basic Statures of Power MOSFET
There is three basic status in the power MOSFET which is following.
- On sate resistance
- Breakdown voltage
- Body diode
On State Resistance
If the power MOSFET is in ON sate, then it produces the resistive behavior in-between the drain & source terminals. We can see in the following figure, that the resistance is the sum of many elementary contributions. The RS resistance is the source resistance. It will show all resistance between the source terminals of the package to the channel of the MOSFET.
The Rch resistance is the channel resistance and this resistance is inversely proportional to the channel width & for a given die size, to the channel density. This resistance is very important contributors to the RDSon of the low voltage MOSFET. The intensive work has done to reduce their cell size with respect to increase the channel density.
The access resistance is represented by the Ra. The access resistance shows the resistance of the epitaxial zone directly to the gate electrode. The current direction is changed from the channel to the vertical.
RJFET is the detrimental effect of the cell size reduction. The P implantation is observed from the gate of a parasitic JFET transistor and it has reduced the width of the current flow.
Rn represents the epitaxial layer and it is used for sustaining the blocking voltage. This resistance is directly related to the voltage rating of the device. The high voltage MOSFET requires a thick low dependent layer which is highly resistive and a low voltage transistor requires a thin layer with the higher doping layer which is very less resistive. This is the main factor for the resistance of high voltage MOSFET.
The RD resistance is the equivalent of resistance of the RS for the drain. The RD resistance, represent the transistor substrate and the package connections.
Break Down Voltage
The power MOSFET is equivalent to the PIN diode, if it is in the OFF state and it is initiated by the P+ diffusion, the N- epitaxial layer and the N+ substrate. This structure is reverse biased when it is highly nonsymmetrical structure and the space charge region extends principally to the lightly doped side, which is the N- layers.
Even though, when the MOSFET is in the ON state, there is a no function of the N- layers. Moreover, it is lightly doped rejoin, intrinsic resistivity is non-negligible and it is added to the MOSFET ON- state drain to source resistance.
There are two important parameters to run both the breakdown voltage and the RDSon of the transistor, which is the doping level and the thickness of the N- epitaxial layer. If the layer is thicker, it has low doping level and the breakdown voltage is high. Similarly, thicker the layer, it has the high doping level and the radon is low. Hence we can observe that there is a trade-off in the design of the MOSFET, between the voltage rating and the ON state resistance.
The body diode can be seen in the following figure that the source metallization is connected to both the N+ and P implantations. Even though the basic principle of the MOSFET requires only that the source should be connected to the N+ zone. Thus, this would result in a floating P zone between the N-doped source and drain. It is equivalent to an NPN transistor with a nonconnected base. Under some conditions like high drain current, in the order of the same volts of an on-state drain to source voltage, this parasitic transistor of NPN should be triggered and make the MOSFET uncontrollable.
The connections of the P implantation to the source metallization short the base terminal of the transistor parasitic to its emitter and it prevents the latching. Hence this solution creates a diode between the cathode & anode of the MOSFET and the current blocks in one direction.
For inductive loads, the body diodes utilize the freewheeling diodes in the configuration of H Bridge & half bridge. Generally, these diodes will have a high forward voltage drop, the current is high. They are sufficient in many applications like reducing part count.
Working with Power MOSFET and Characteristics
The construction of the power MOSFET is in V-configurations, as we can see in the following figure. Thus the device is also called as the V-MOSFET or V-FET. The V- the shape of power MOSFET is cut to penetrate from the device surface is almost to the N+ substrate to the N+, P, and N – layers. The N+ layer is the heavily doped layer with a low resistive material and the N- layer is a lightly doped layer with the high resistance region.
Both the horizontal and the V cut surface are covered by the silicon dioxide dielectric layer and the insulated gate metal film is deposited on the SiO2 in the V shape. The source terminal contacts with the both N+ and P- layers through the SiO2 layer. The drain terminal of this device is N+.
The V-MOSFET is an E-mode FET and there is no exists of the channel in between the drain & source till the gate is positive with respect to the source. If we consider the gate is positive with respect to the source, then there is a formation of the N-type channel which is close to the gate and it is in the case of the E-MOSFET. In the case of E-MOSFET, the N-type channel provides the vertical path for the charge carriers. To flow between the drain and source terminals. If the VGS is zero or negative, then there is no channel of presence and the drain current is zero.
The following figures show the drain & transfer characteristics for the enhancement mode of N-channel power MOSFET is similar to the E-MOSFET. If there is an increase in the gate voltage then the channel resistance is reduced, therefore the drain current ID is increased. Hence the drain current ID is controlled by the gate voltage control. So that for a given level of VGS, ID is remaining constant through a wide range of VDS levels.
The channel length of the power MOSFET is in the diffusion process, but in the MOSFET the channel length is in the dimensions of the photographic masks employed in the diffusion process. By controlling the doping density and diffusion time, the channel length will become shorter. The shorter channels will give, the more current densities which will contribute again to larger power dissipation. It also allows a larger transconductance gm to be attained in the V-FET.
In the geometry of power MOSFET, there is an important factor which is the presence of lightly doped, N- epitaxial layer which is close to the N+ substrate. If the VGS is at zero or negative, then the drain is positive with respect to the source and there is a reverse biased between the P- layer & N- layer. At the junction the depletion region penetrates into the N- layer, therefore it punch-through the drain to the source are avoided. Hence, relatively high VDS are applied without any danger of device breakdown.
In the power MOSFET, there is available of P-channel. The characteristics are similar to the N-channel MOSFET. The direction of the current and voltage polarities are in reverse direction.
MOSFET Power Amplifier
There are different types of MOSFET power amplifiers like 300W MOSFET power amplifier, 240W MOSFET power amplifier, 160W MOSFET power amplifier and 100W MOSFET power MOSFET amplifier. But here we are explaining about the 100W MOSFET power amplifier with its circuit.
100W MOSFET Power Amplifier Circuit Operation
The circuit operation of 100w MOSFET amplifier consists of PNP transistor from the differential amplifier circuit. The AC input signal is sent to one of the transistors and the other transistor gets the output signal from the feedback. The AC signal is a coupled to the base terminal of the transistor Q1 with the help of the coupling capacitor and the feedback signal. The feedback signal is fed into the base terminal of the second transistor Q2 with the help of resistor R5 & R6. The potentiometer is used to set the output of the amplifier.
The first stage differential output amplifier is fed to the second stage differential amplifier input. In the case of the first differential amplifier, when the input voltage is more than the feedback voltage than the input voltage of the two transistors Q3 and Q4 of second differential amplifier differs from each other. The current mirror circuit of the transistors is Q5 & Q6. This circuit ensures the flowing of output current in the push-pull amplifier circuit is constant.
Thus, this circuit can be achieved because, when the collector current of transistor Q3 is increased, the collector current of Q4 decreases is to maintain the flow of constant current through the universal point of the emitter terminal of the transistors Q3 &Q4. There is an equal output current in between the current mirror circuit & collector current of the Q3 transistor. The potentiometer R12 protects the applications of DC biasing to each MOSFET because the two MOSFETs are in the balancing to each other.
If the positive voltage is applied to the gate terminal of the Q7 transistor then it will conduct. Correspondingly transistor Q8 will conduct for the negative threshold voltage. To prevent the MOSFET output from the oscillating the gate resistors are used.
Applications of Power MOSFET
The power MOSFET’s are used in the power supplies
- DC to DC converters
- Low voltage motor controllers
- These are widely used in the low voltage switches which are less than the 200V
This article will give the information on the working principle of power MOSFET circuit and its applications. I hope by reading this article you have gained some basic information on the power MOSFET. If you have any queries about this article or to implement electronic projects for engineering students, please feel free to comment in the below section. Here is the question for you, what are the functions of the power MOSFET?
Day by day, as the technology is rapidly progressing that affect the human daily lives more flexible, especially in controlling home appliances. Electrical installations are the heart of every building, thus intelligent building control absolutely ensures the safety and efficient control and finally saves the power consumption and manpower. Home automation system does the operations such as lighting control & regulation, regulating heating, equipment’s ventilation and air con equipment, load, and energy management, audio or video systems, security and monitoring, human machine interfaces and other control tasks.
RF Based Home Automation System
To develop a home automation system with an RF controlled remote, houses are also getting smarter. As technology is advancing so houses are also getting smarter.Modern houses are gradually shifting from conventional switches to a centralized control system, involving radio frequency controlled switches.
At present, conventional wall switches located in different parts of the house make it difficult for the operator to go near them to operate.In order to complete this, an RF remote is interfaced to the microcontroller on the TX side which sends commands to the receiver where different loads are connected. By operating the particular remote switch on the TX, the loads can be switched ON/OFF remotely through wireless technology.
This circuit uses an RF module to make a wireless remote, which could be used to drive an o/p from a distance place. As the name suggests, RF module uses radio frequency to send signals, which are transmitted at a specific frequency & a baud rate.
Hardware and Software Requirements
The hardware and software requirements of RF-based home automation system include Series Microcontroller, Transformer, Opto-isolator, TRIAC, Voltage Regulator, Crystal Diodes, Resistors, Capacitors, Lamps, RF modules, Push Buttons, Keil compiler, and Languages: Embedded C or Assembly.
RF Transmitter and Receiver
- Normally, RF modules are divided into three groups, RF TX module, RF receiver module, and RF transceiver module.
- 433MHz, ASK transmitter and receiver are used for the remote control.
Features of RF
The main features of RF transmitter include the following
- Range in standard conditions is 100 meters
- RX frequency-433MHz
- Typical sensitivity-105Dbm
- Supply current of RX-3.5 mA
- IF frequency of RX-1MHz
- Low power consumption
- Easy for Application
- Operating voltage of RX-5V
- Frequency range of TX-433.92MHz
- Supply voltage of TX- 3V to 6VO/p of TX- 4 to 12 dBm
- Encoder HT12E IC gets parallel data in the form of address and control bits
- The control signals from remote switches along with 8-bits constitute a set of 12 parallel signals
- The encoder converts the parallel inputs into a serial set of signals.
- These signals are serially transmitted through RF to the response point.
- Transmission is permitted by providing ground to pin-14 which is active low.
- In the receiver circuit, we use an RF module to get the information and decoded by the decoder.
- Decoder delivers the data into 4-bit and we use the further control circuit to switch ON/OFF.
- The decoder is used after the RF receiver to decode the serial format and regain the original signals as o/ps.
- This o/ ps can be observed on equivalent LEDs.
- Opto-coupler MOC3061 or MOC3063 a LED, SCR sort combination.
- It is a 6-pin IC.
- Additionally, while using this IC with a microcontroller and also LED can be connected in series with IC LED to specify when the high is given from microcontroller so that we can know that flow of current is in internal LED of the opto-IC.
- When the logic high is given, then the current flow through LED from pin 1 to 2
- So in this process, LED falls on SCR to cause pins 4 and 6 to close only at the zero cross of the supply voltage.
BC547 NPN Transistor
- The transistor (BC547) is an NPN epitaxial silicon transistor
- This transistor is used in general purpose switching & amplification BC847 or BC547 series 45V, 100mA NPN general purpose transistors.
- The ratio of two currents ‘Ic’ and ‘Ib’ is called the C current gain of the device and is given the symbol of hfe or beta.
- The current gain from the Emitter (E) to the collector terminal is called alpha.
The main goal of this project is to design a home automation system with an RF controlled remote. As day by day technology is advancing and houses are getting smarter. These houses are progressively changing from conventional switches to the integrated control system, including RF controlled switches.
Presently, conventional wall switches located in various parts of the house make it difficult for the user to go nearby them to work. Even more, it becomes more difficult for the elderly or physically handicapped people to do so. The proposed system offers a simple solution with RF technology.
In order to get this, an RF remote is connected to the microcontroller on the TX side which sends ON/OFF signals to the RX where different loads are connected. By operating the particular remote switch on the TX, the loads can be switched ON/OFF remotely through wireless technology.
The microcontroller used here is 8051 family, the different loads are connected to the microcontroller using TRIACs and Opto-isolators.
Applications of RF-Based Home Automation System
The applications of RF-based home automation system include the following
- Burglar alarm, smoke alarm, fire alarm, car alarm, security system, etc.
- Car door and garage door controllers
- Cordless telephone
- Other remote control systems
- Wireless security systems
- Car alarm systems
- Remote controls
- Sensor reporting
Thus, this is all about RF based home automation system. We hope that you have got a better understanding of this concept. Furthermore, any queries regarding this concept or to implement any home automation projects, please give your valuable suggestions by commenting in the comment section below. Here is a question for you, What are the applications of home automation system?
Nowadays, the necessity of the solar inverter has been increased. A solar inverter is a common inverter but uses energy from the sun that is solar energy. This type of inverter aids in changing the DC into AC using solar power. DC is the power which flows in one direction in the circuit and helps in providing current when there is no electricity. Direct current is used for small appliances such as gadgets, iPod, MP3 players, etc. where there is power stored in the battery. In the case of AC (alternative current) is the power that supplies back and forth inside the circuit. Generally, the AC power is used for household appliances.A solar inverter helps many devices that run on DC power to run on AC power so that the operator makes use of the AC power. If you are thinking why to use this inverter as an alternative to the normal electric one, then it is because the solar inverter makes use of the solar energy which is obtainable in ample from the Sun and is clean and also pollution free.