The Faraday's Club of Electrical Igniters

30/09/2015

THE FARADAY'S CLUB is back with its most interesting and very useful product i.e. INVERTER as a workshop on 6th october. please do participate in the workshop.certificates are issued by the ISTE-CHAPTER OF SNIST. LIMITED REGISTRATIONS ONLY. HURRY UP!!!!!!

Date: 6th Oct
Registration Fee: Rs.350(per head) and Rs.500(for team of 2)
Get registered in the link given below..
https://docs.google.com/forms/d/1Q_ARvGgjRsrxVbHQWll5OFwZ3-myhaImM_ipgzhhK5M/viewform

14/03/2015

The Campus Connect - SNIST

mentioned us specially 4r conducting

" Power Bank " work shop in Adastra 2015

ty :) The Campus Connect

The Institute of Electrical and Electronics Engineers (IEEE) students’ chapter of SNIST; a conjuncture of engineers, scientists and students; has recoiled once…

14/03/2015

A MEGA quiz event for the GENERAL ELECTRICAL AND APTITUDE by THE FARADAY' CLUB OF ELECTRIC IGNITERS ON 19TH MARCH 2015 TIMINGS:12:30--1:30 JOIN WITH US AND SHOW YOUR SKILL IN APTITUDE..

22/02/2015

What you want as the Next article among the

topics mentioned here ?

1.

This circuit is used to block the signals of cell phones with in the range of 100 meters. This circuit can be used in TV transmission and also for remote controlled toys or play things.

2.

helps us to intimate others regarding our bad situation without any delay. It is more useful when an intruder entering our house or bad health status at which we are unable to intimate to the people around us.

3.

Lead Battery is a rechargeable battery and is more useful in our real life as it will dissipate very little energy, it has very low energy to weight ratio, it can deliver high current, can work for long time with high efficiency and is very low cost.

22/02/2015

" Cell Phone Detector Circuit "

The most common electronic equipment used is cell phones. With advancement in communication technology, the requirement of cell phones has increased manifold. A cell phone typically transmits and receives signals in the frequency range of 0.9 to 3 GHz. This article provides a simple circuit to detect the presence of an activated cell phone by detecting these signals.

Basic Principle of Mobile Phone Detector Circuit :-

The basic principle behind this circuit is the idea of using a Schottky diode to detect the cell phone signal. Mobile phone signal is in the frequency range of 0.9 to 3GHZ. Schottky diodes have a unique property of being able to rectify low frequency signals, with low noise rate. When an inductor is placed near the RF signal source, it receives the signal through mutual induction. This signal is rectified by the Schottky diode. This low power signal can be amplified and used to power any indicator like an LED in this case.

Circuit Components :-

V 1 = 12 V
L 1 = 10 uH
R 1 = 100 ohms
C 1 = 100 nF
R 2 = 100 K
R 3 = 3 K
Q 1 = BC 547
R 4 = 200 Ohms
R 5 = 100 Ohms
IC 1= LM 339
R 6 = 10 Ohms
LED = Blue LED

Cell Phone Detector Circuit Design :-

(i) Detector Circuit Design :-
The detector circuit consists of an inductor, diode, a capacitor and a resistor. Here an inductor value of 10 uH is chosen. A Schottky diode BAT 54 is chosen as the detector diode, which can rectify low frequency AC signal. The filter capacitor chosen in a 100 nF ceramic capacitor, used to filter out AC ripples. A load resistor of 100 Ohms is used.

(ii) Amplifier Circuit Design :-
Here a simple BJT BC547 is used in common emitter mode. Since the output signal is of low value, the emitter resistor is not required in this case. The collector resistor value is determined by the value of battery voltage, collector emitter voltage and collector current. Now the battery voltage is chosen to be 12 V (since maximum open source collector emitter voltage for BC 547 is 45V), operating point collector emitter voltage is 5 V and collector current is 2 MA. This gives a collector resistor of approx 3 K. Thus a 3 K resistor is used as RC. The input resistor is used to provide bias to the transistor and should be of larger value, so as to prevent the flow of maximum current. Here we chose a resistor value of 100 K.

(iii) Comparator circuit Design :-
Here LM339 is used as comparator. The reference voltage is set at the inverting terminal using a potential divider arrangement. Since output voltage from the amplifier is quite low, the reference voltage is set low of the order of 4V. This is achieved by selecting a resistor of 200 Ohms and a potentiometer of 330 Ohms. An output resistor of value 10 Ohms is used as a current limiting resistor.

Mobile Phone Tracking Circuit Operation :-
In normal condition, when there is no RF signal, the voltage across the diode will be negligible. Even though this voltage is amplified by the transistor amplifier, yet the output voltage is less than the reference voltage, which is applied to the inverting terminal of the comparator. Since the voltage at non inverting terminal of the OP AMP is less than the voltage at the inverting terminal, the output of the OP AMP is low logic signal.

Now when a mobile phone is present near the signal, a voltage is induced in the choke and the signal is demodulated by the diode. This input voltage is amplified by the common emitter transistor. The output voltage is such that it is more than the reference output voltage. The output of the OP AMP is thus a logic high signal and the LED starts glowing, to indicate the presence of a mobile phone. The circuit has to be placed centimeters away from the object to be detected.

Have a nice day :)

Theory Behind Cell Phone Tracking System :-

Mobile Phone Signal Detection using Schottky Diode:

The signal from mobile phone is a RF signal. When a mobile phone is present near the circuit, the RF signal from the mobile induces a voltage in the inductor via mutual induction. This AC signal of high frequency of the order of GHz is rectified by the Schottky diode. The output signal is filtered by the capacitor. Schottky diodes are special diodes formed by combining N type semiconductor material with a metal and are typically low noise diodes, operating at a high frequency. These diodes have a unique property of conducting at a very low forward voltage between 0.15 to 0.45V. This enables the diode to provide high switching speed and better system efficiency. The low noise is due to the very low reverse recovery time of about 100 per sec.

Signal Amplifier using BJT :-

BJT or bipolar junction transistor in its common emitter form is the most common amplifier used. A transistor amplifier works on the fact that the input base current is amplified to the output collector current by a factor of β. Here the emitter is the common terminal. The circuit is biased using a voltage divider circuit formed by combination of two resistors. When a transistor is biased in active region, i.e. the emitter base junction is forward biased and the collector base junction is reverse biased, a small base current results in a larger collector current.

LM 339 as Comparator :-

LM 339 is a comparator IC containing 4 comparators. Here we are using only one comparator. When the voltage at non inverting (+) terminal is higher than the voltage at inverting terminal, the output voltage goes high. When the voltage at inverting terminal is higher, the output voltage goes low.

Cell Phone Detector Circuit Applications :-

1.This circuit can be used at examination halls, meetings to detect presence of mobile phones and prevent the use of cell phones.

2.It can be used for detecting mobile phones used for spying and unauthorized transmission of audio and video.

3.It can be used to detect stolen mobile phones.



Limitations of Mobile Phone Detector Circuit :-

1.It is a low range detector, of the order of centimeters
2.The Schottky diode with higher barrier height is less sensitive to small signals.

08/02/2015

" IR Remote Control Switch "

This circuit is low cost and can be constructed easily. By using this circuit, we can control any house hold appliance with the help of remote. In this project, there are two parts – one is in transmitting section and the other is in receiving section. Receiving section will be in a stable position which is connected to any load and transmitter will act as a normal remote.

Block Diagram Explanation :-

1. The main function of this remote control switch is to control any load (TV, Radio, Stereo, Fan, Light, etc.). In this circuit, we are using one switch for operating the transmitter, with this we can switch on or off the TV, motor, radio or any other home appliances.

2. We can even control the volume of TV, radio and many more by adding extra circuitry to the actual circuit. Here in the transmitter section, we have NE555 timer which is configured in astable mode and infrared LEDs whose infrared rays are directed by the concave lens and the source of power is from 9V battery.

3. Switch in the circuit plays the key role in the transmitter circuit. When the switch is closed, the power from the battery turns on the NE555 timer which will act as an astable multivibrator. The infrared LEDs which are connected to the output of NE555 will get high and produce the infrared beam through the concave lens.

4. When the infrared beam from the transmitter is reached by the receiver section, the photo LEDs will receive the infrared beam and charge the capacitor which will increase the input voltage of one pin of operational amplifier and high output is generated. This high output is given to the 4018 Counter as input and counter will drive the load through a relay to switch on or switch off accordingly.

Infrared Remote Control Switch Circuit Components :-

(1).CA3130: - CA3130 is a BiCMOS operational amplifier, which has very high input impedance, very low input current and high speed performance. It had very low input swing i.e. below 0.5V; the operating supply voltage is of around 5V to 16V. It will permit the output swing also. Maximum differential voltage between two inputs should be 8V. The main applications are they are used as single supply amplifiers, timers or monostable multivibrators, voltage followers and detectors, peak detectors etc. They can also be used in photodiode – a sensor amplifier that’s why we use this component in our circuit as amplifier.

(2). CD4018:- The main function of counter is to store (and sometimes displays) the number of times a particular event or process has occurred, often in relationship to a clock signal. CD4018 is the 16 pin counter in which there are 5 jam inputs (sets the counter to that number and sends the number out immediately. If the number is outside the minimum and maximum count range, this message is ignored), clock, data, preset, enable and reset pins. It had around 5 Johnson counter (twisted ring counter) in which output of the last stage is inverted back and given as input to the first stage. The main features are fully static operations, different noise margins at different voltages (1V noise margin is 5V), supply voltage ranges from 3V to 18V. Clock input frequency also varies at different supply voltage. 5V VDD will give around 3Mhz frequency. Counters are used in different applications like frequency division, counter control, programmable decade counter, minicomputer, etc.

Circuit Explanation :-
1. In the receiver section there are 3 photodiodes which will detect the infrared signals from the receiver and produce leakage current to the capacitor C1. This current is given to the inverting input of 3130 IC which will get triggered by this current and give amplified output. Remaining all other pins are connected to the ground.
2. R2 and C2 are used to stop the unwanted signals from triggering the IC. C3 is used for high gain which is used as comparator amplifier.
3. The output of IC3130 is given to the pin14 CLK of Johnson counter 4018. The output of 4018 IC will go high by applying successive clock pulses.
4. The resistor R4 is used to stop loading the transistor. The transistor will get ON when the output of 4018 is high and drive the relay to operate in 12V. The diode D4 will protect the relay from reverse current.
5. The relay will switch ON or OFF the appliance that is connected to it. LED will act as a visual indicator and also stops the reverse voltage which will effect the counter.
6. In the transmitter section, the 555 timer is configured in astable mode and resistors R5, R6 and capacitor C6 are adjusted to give the 5Khz operating frequency.
7. When the switch is ON, the capacitor C6 will get charged and when the switch is OFF, it will be discharged through R6 and 555 timer internal transistors. When switch on the 555 timer, output pin3 will be high this will trigger the transistor SK100.
8. Resistor R7 is used to stop loading of transistor. When transistor is ON, the infrared diodes which are connected to it will produce high intensity invisible infrared beam which should be given to the photo diodes of receiver.

NOTE :-

1. Operating voltage can be between 6V to 15V.
2. Relay voltage rating should be equal to the main power supply.
3. Heat sink can be attached to the transistor SK100 for compensating the heat dissipation.
4. Concave lens is used for producing the strong rays of high intensity.
5. The disadvantage in the circuit is switching time between the transmitter and receiver (if we produce the signal from transmitter, again we have to produce the signal after 5 to 6 seconds). Rapid switching like regular remote cannot be done.

Applications of Infrared Remote Control Switch :-

1. This circuit can be used for switch ON or OFF the TV, radio, washing machine and any electronic appliances.
2. By using the relative relays, we can even switch ON or switch OFF the motor appliances also.

08/02/2015

" AUTO NIGHT LAMP USING HIGH POWER LED's "

Auto Night Lamp Using High Power LEDs is a circuit which turns ON the LED lights interfaced to it at night time and it turns OFF the lights automatically when it is day. Usage of LEDs is growing day by day due to the advantages they provide compared to the conventional filament bulbs or fluorescent lamps. They provide good quality of white light with a better intensity compared to others. They also consume less power compared to their alternatives. These are the advantages which the LEDs encourage us to use them compared to their alternatives.

In this article, we shall see the circuit and the working of turning on or off of high power LEDs with light intensity. The element which is used for sensing light in the circuit is the light dependent resistor. The resistance of the light dependent resistor depends on the light incident on it. If the intensity of light incident on it is more, then the resistance of the circuit decreases. If the intensity of light incident on it decreases, then the resistance of the device increases. We are making use of this property of the light dependent resistor to detect the light and thereby operate the LEDs. We are arranging twenty five light emitting diodes in an array such that five LEDs are in series and five such series LEDs are arranged in parallel.

Do you know about How a Light Activated Switch Circuit Works?

Circuit Diagram of Auto Intensity Control of LED Lights:
Auto Night Lamp Using LED Circuit

The transistors are used in saturation mode. They are used as electronic switches in this mode. The transistor BC547 is a general purpose NPN transistor which is used to further switch the LEDs. This is a power transistor with a heat sink. The heat sink helps the transistor to dissipate the generated heat into air so that the transistor can handle higher power loads than it can do without the heat sink.

The entire circuit along with the LEDs is powered by a 12V DC power supply. A battery based DC power supply is usually preferred. However, you can use a ac rectified and regulated power supply.

The LEDs used in the circuit are high powered white LEDs. The intensity of light produced by these LEDs equals an ordinary fluorescent bulb. The lighting produced is sufficient for reading or to do any other daily activity. The circuit can be assembled on a printed circuit board with all the components neatly arranged and the LEDs placed in order. Try to place the LEDs maintaining a distance of about 1 cm between the LEDs so that the the lighting will be well distributed in your room.

27/01/2015

Tomarrow there is a session of THE FARADAY'S CLUB OF ELECTRICAL IGNITERS from 4:30 to 7:00 transportation is provided till Uppal and Ecil all the students are requested to present over there.........

23/01/2015

in the process of doing a project :)

23/01/2015

a project of building a LED sign

23/01/2015

many more projects and electronics are present 4r us to work on