Running Message Display

Running Message Display

Click here for the circuit diagram

Light emitting diodes are advan- tageous due to their smaller size, low current consumption and catchy colours they emit. Here is a running message display circuit wherein the letters formed by LED arrangement light up progressively. Once all the letters of the message have been lit up, the circuit gets reset. The circuit is built around Johnson decade counter CD4017BC (IC2). One of the IC CD4017BE’s features is its provision of ten fully decoded outputs, making the IC ideal for use in a whole range of sequencing operations. In the circuit only one of the outputs remains high and the other outputs switch to high state successively on the arrival of each clock pulse. The timer NE555 (IC1) is wired as a 1Hz astable multivibrator which clocks the IC2 for sequencing operations. On reset, output pin 3 goes high and drives transistor T7 to ‘on’ state. The output of transistor T7 is connected to letter ‘W’ of the LED word array (all LEDs of letter array are connected in parallel) and thus letter ‘W’ is illuminated. On arrival of first clock pulse, pin 3 goes low and pin 2 goes high. Transistor T6 conducts and letter ‘E’ lights up. The preceding letter ‘W’ also remains lighted because of forward biasing of transistor T7 via diode D21. In a similar fashion, on the arrival of each successive pulse, the other letters of the display are also illuminated and finally the complete word becomes visible. On the following clock pulse, pin 6 goes to logic 1 and resets the circuit, and the sequence repeats itself. The frequency of sequencing operations is controlled with the help of potmeter VR1.
The display can be fixed on a veroboard of suitable size and connected to ground of a common supply (of 6V to 9V) while the anodes of LEDs are to be connected to emitters of transistors T1 through T7 as shown in the circuit. The above circuit is very versatile and can be wired with a large number of LEDs to make an LED fashion jewellery of any design. With two circuits connected in a similar fashion, multiplexing of LEDs can be done to give a moving display effect

Weather Station

Weather Station

This project on the TechDesign Electronics Web site uses the PIC 18F452 microcontroller, pressure, temperature, and humidity sensors along with radio transmitter and receiver modules to allow you to monitor the weather.

click here to view about this project

Sound Pressure Level Meter

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Suitable for home-cinema setup

9 Volt operated portable unit

Circuit diagram:

Parts:

R1______________10K  1/4W Resistor
R2,R3___________22K  1/4W Resistors
R4_____________100K  1/4W Resistor
R5_____________100R  1/4W Resistor

C1_______________1µF  63V Polyester or Electrolytic Capacitor
C2_____________100µF  25V Electrolytic Capacitor
C3_____________220µF  25V Electrolytic Capacitor

D1-D4_________BAT46  100V 150mA Schottky-barrier Diodes

IC1__________CA3140  Op-Amp IC

MIC___________Miniature electret microphone (See Notes)

J1,J2___________4mm  Output sockets

SW1____________SPST  Toggle or Slider Switch

B1______________9V   PP3 Battery

Clip for PP3 Battery

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Comments:

This project was requested by some correspondents wishing to setup their home-cinema set adjusting all the loudspeaker outputs to the same level when heard from the listening position.
In practice this device is a simple (though linear and precise) ac millivoltmeter, using an existing multimeter set to 50 or 100µA fsd with the probes connected to J1 and J2 to read the results.
The precision of the measure is entirely depending on the frequency response of the microphone used but, fortunately, for the main purpose of this circuit an absolutely flat response is not required. Therefore, a cheap miniature electret microphone can be used.

Use:

The amplifiers driving the loudspeakers must be fed, one at a time, with a sine wave in the 400Hz - 1KHz range, but different values can also be chosen. For this purpose you can use a simple signal generator circuit like one of those available on this site, namely: 1KHz Sine wave Generator or, better still, Spot-frequency Sine wave Generator.
As an alternative, the input sine wave can be provided by a CD test track, a cassette-tape or a personal computer.
Please be careful and set the volume control very low, to avoid loudspeakers' damage. Switch-on the Sound Pressure Level Meter and increase the volume of the amplifier in order to obtain an approximate center-scale reading. Repeat the same steps with all channels.

Notes:

• If external electret (battery powered) or dynamic microphone types are used, R1 must be omitted.
• Using a good quality microphone, this circuit can be very useful in setting-up parametric equalizers or tone controls in HiFi chains etc.

Induction Receiver

Induction Receiver

The induction receiver shown below is very sensitive and can serve a variety of purposes. It is excellent for tracing wiring behind walls, receiving audio from an induction transmitter, hearing lightning and other electric discharges, and monitoring a telephone or other device that produces an audio magnetic field ("telephone pickup coil").

The receiving coil could be a "telephone pickup coil" if available or a suitable coil from some other device. The coil in the prototype was salvaged from a surplus 24 volt relay. Actually, two relays were needed since the first was destroyed in the attempt to remove the surrounding metal so that a single solenoid remained. Epoxy putty was used to secure the thin wires and the whole operation was a bit of a challenge. A reed relay coil will give reduced sensitivity but would be much easier to use. The experimentally inclined might try increasing the inductance of a reed relay by replacing the reed switch with soft iron. Avoid shielded inductors or inductors with iron pole pieces designed to concentrate the magnetic field in a small area or confine it completely (as in a relay or transformer) unless you can remove the iron. The resulting coil should be a simple solenoid like wire wrapped around a nail. Don't try to wind your own - it takes too many turns. Evaluate several coils simply by listening. Coils with too little inductance will sound "tinny" with poor low frequency response and other coils will sound muffled, especially larger iron core coils. This prototype was tested with a large 100 mH air core coil with superb results but the 2 inch diameter was just too big for this application.

The other components are not particularly critical. The 2N4401 can be just about any NPN general purpose small-signal transistor. The TL431 is a shunt voltage regulator but it is being used as an audio amplifier in this circuit. In fact, the whole device is nothing more than a low noise, high gain audio amplifier with a pickup coil connected to the input and other amplifiers will work equally well.

The circuit is built into a 8 mm cassette box with the power switch and earphone jack in the back. The circuit board is a piece of pink countertop laminate which looks good against the violet hue of the cassette box. The battery fits nicely into the box and a piece of foam fills in the remaining space. These video cassette boxes make nice project boxes, unlike audio cassette boxes which are too flimsy.

When you first turn on the unit you will probably hear a lot of buzzing from the wiring in the room. Rotate the receiver in a horizontal plane to find a "null" where the hum is minimal. If you can get a reasonable null, you should be able to hear distant lightning crackles or other magnetic noises. If you cannot get a null then go outside away from the building. Try holding the coil near electronic devices like your computer monitor, telephone (when in use), cell phone readout, etc. You can trace power wires behind a wall or ceiling by listening for a sharp increase in hum as the coil passes near the wire. Make sure that current is flowing in the wires to be traced by turning on a lamp or other appliance. (Here is an experiment to try: Build a line voltage lamp flasher that can be connected to the circuit to be traced. The desired wire will now have an on and off buzz - buzz sound that will be easy to distinguish. I wonder if you could even identify a specific breaker or fuse?)

Other wires can be traced if they are carrying alternating current in the audio range or a signal generator can be connected to produce the current. Connect the generator to the wire to be traced and connect the generator's "ground" to the house wiring ground. Also ground the far end of the wire you are tracing so that current flows in the wire. This ground connection can also just be a temporary wire laying on the floor running from the generator ground to the far end of the wire you wish to trace.

For the ambitious: try wrapping one or two turns of wire around the whole house and connect the loop to the output of an audio power amplifier (one channel of a stereo should work). Add a 4 ohm, high wattage resistor in series to protect the amplifier. You should be able to pick up the magnetic field fairly easily anywhere within the loop with the power amplifier supplying just a few watts of power.

Clap Activated Remote

Clap Activated Remote

Click here for the circuit diagram

An infra-red or wireless remote control has the disadvantage that the small, handy, remote transmitter is often misplaced. The sound operated switch has the advantage that the transmitter is always with you. This project offers a way to control up to four latching switches with two claps of your hand. These switches may be used to control lights or fans – or anything else that does not produce too loud a sound. To prevent an occasional loud sound from causing malfunction, the circuit is normally quiescent. The first clap takes it out of standby state and starts a scan of eight panel-mounted LEDs. Each of the four switches are accompanied with two LEDs – one for indicating the ‘on’ and the other for indicating the ‘off’ state. A second clap, while the appropriate LED is lit, activates that function. For example, if you clap while LED10 used in conjunction with Lamp 1 is lit then the lamp turns on. (If it is already on, nothing happens and it remains on.) A condenser microphone, as used in tape recorders, is used here to pick up the sound of the claps. The signal is then amplified and shaped into a pulse by three inverters (N1 through N3) contained in CMOS hex inverter IC CD4069. A clock generator built from two of the inverter gates (N5 and N6) supplies clock pulses to a decade counter CD4017 (IC2). Eight outputs of this IC drive LEDs (1 through 8). These outputs also go to the J and K inputs of four flip-flops in two type CD4027 ICs (IC3 and IC4). The clock inputs of these flip-flops are connected to the pulse shaped sound signal (available at the output of gate N3). Additional circuitry around the CD4017 counter ensures that it is in the reset state, after reaching count 9, and that the reset is removed when a sound signal is received. Outputs of the four flip-flops are buffered by transistors and fed via LEDs to the gates of four triacs. These triacs switch the mains supply to four loads, usually lamps. If small lamps are to be controlled, these may be directly driven by the transistors. If this circuit is to be active, i.e. scanning all the time, some components around CD4017 IC could be omitted and some connections changed. But then it would no longer be immune to an occasional, spurious loud sound. The condenser microphone usually available in the market has two terminals. It has to be supplied with power for it to function. Any interference on this supply line will be passed on to the output. So the supply for the microphone is smoothed by resistor-capacitor combination of R2, C1 and fed to it via resistor R1. CD4069, a hex unbuffered inverter, contains six similar inverters. When the output and input of such an inverter is bridged by a resistor, it functions as an inverting amplifier. Capacitor C2 couples the signal developed by the microphone to N1 inverter in this IC, which is configured as an amplifier. The output of gate N1 is directly connected to the input of next gate N2. Capacitor C3 couples the output of this inverter to N3 inverter, which is connected as an adjustable level comparator. Inverter N4 is connected as an LED (9) driver to help in setting the sensitivity. Preset VR1 supplies a variable bias to U3. If the wiper of VR1 is set towards the negative supply end, the circuit becomes relatively insensitive (i.e. requires a thunderous clap to operate). As the wiper is turned towards resistor R4, the circuit becomes progressively more sensitive. The sound signal supplied by gate N2 is added to the voltage set by preset VR1 and applied to the input of gate N3. When this voltage crosses half supply voltage, the output of gate N3 goes low. This output is normally high since the input is held low by adjustment of preset VR1. This output is used for two things: First, it releases the reset state of IC2 via diode D1. Second, it feeds the clock inputs to the four flip-flops contained in IC3 and IC4. In the quiescent state, IC2 is reset and its ‘Q0’ output is high. Capacitor C4 is charged positively and it holds this charge due to the connection from R5 to this output (Q0). IC2 is a decade counter with fully decoded outputs. It has ten outputs labelled Q0 to Q9 which go successively high, one at a time, when the clock in put is fed with pulses. IC3 and IC4 are dual JK flip-flops. In this circuit they store (latch) the state of the four switches and control the output through transistors and triacs. At the first clap, the output of gate N3 goes low. Diode D1 is forward biased and it conducts, discharging capacitor C4. The reset input of IC2 goes low, releasing its reset state. All the J and K inputs of the four flip-flops are low and so these do not change state, even though their clock inputs receive pulses. When the reset input of IC2 is low, each clock pulse causes IC2 to advance by one count and its outputs go high successively, lighting up the corresponding LEDs and pulling high the J and K inputs of the four flip-flops, one after the other. Resistor R8 limits the current through LEDs 1 through 8 to about 2 mA. Larger current might cause malfunction due to the outputs of IC2 being pulled down below the logic 1 state input voltage. If a second clap is detected while the J input of a particular flip-flop is high, its Q output will go high, regardless of what state it was in previously. Similarly, if its K input was high, the output will go low. (If both J and K are high, the output will change state at each clock pulse.) Thus although all flip-flops receive the clap signal at their clock inputs, only the one selected by the active output of IC2 will change state. Resistor R9 and capacitor C6 ensure that the flip-flops start in the off state when power to the circuit is switched on, by providing a positive power-on-reset pulse to the reset input pins when power is applied. The preset input pins are not used and are therefore connected directly to ground. When, after eight clock pulses, output Q8 of IC2 becomes high, diode D2 conducts, charging capacitor C4, thereby resetting IC2 and making its Q0 output high. And there it stays, awaiting the next clap. The four Q outputs of IC3 and IC4 are buffered by npn transistors, fed through current limiting resistors and LEDs (to indicate the on/off state of the loads) to the gates of four triacs. Four lamps operating on the mains may thus be controlled. For demonstrations, it might be better to drive small lamps (drawing less than 100 mA at 12V) directly from the emitters of the transistors. In this case the triacs, LEDs and their associated current limiting resistors may be omitted. It has to be noted that one side of the mains has to be connected to the negative supply line of this circuit when mains loads are to be controlled. This necessitates safe construction of the circuit such that no part of it is liable to be touched. The advantage is that it may be mounted out of reach of curious hands since it does not need to be handled during normal operation. It is advisable to start with the low voltage version and then upgrade to mains operation, once you are sure everything else is working satisfactorily. CMOS ICs are used in this circuit for implementing the amplifying and logic functions. Use of a dedicated supply is recommended because the integrated circuits will be damaged if the supply voltage is too high, or is of wrong polarity. An external power supply may get connected up the wrong way around, or be inadvertently set to too high a voltage. Therefore it is a good idea to start by constructing the power supply section and then add the other components of the circuit. If the clock is working, you may turn your attention to the amplifier. LED9 should be off, and should flash when the terminals of capacitor C2 are touched with a wet finger (the classic wet finger test). Preset VR1 may need to be adjusted until LED9 just turns off. The output of gate N2 will be at about half the supply voltage. The output of gate N3 would normally be high. The voltage at the input of gate N3 should vary when preset VR1 is varied. High-efficiency LEDs should preferably be used in this circuit. The microphone has two terminals, one of which is connected to its body. This terminal has to be connected to circuit ground, and the other to the junction of resistor R2 and capacitor C2. These wires are preferably kept short (one or two centimetres) to avoid noise pickup. With the microphone connected, a loud sound (a clap) should result in LED9 blinking. Adjust preset VR1 so that LED9 stays off on the loudest of background noises but starts glowing when you clap. If the clap-to-start feature is not required, it may be disabled by omitting components D1, D2, R5, C4 and connecting a wire link in place of diode D2. Then IC2 will be alive and kicking all the time.

Photic phone

Photic phone LASER LINK FOR VOICE TRANSMISSION FIBER OPTIC LINK FOR VOICE TRANSMISSION

Using a single ultrabright l.e.d., this simple low-cost, high security, optical voice link achieved a range of four metres, and 15 metres with a single lens(not included in the kit) This project slices up the human voice into forty-thousand binary segments a second, transmits it over a light-beam, then re-integrates it at the other side. That is, it applies pulse width modulation (p.w.m.) to the voice, to create a binary transmission. This is far more advantageous than similar analogue circuits, which typically achieve a range of no more than a few metres. The circuit presented here has a range approximately five times greater than similar analogue circuitWithout the use of lenses, the prototype Photic Phone achieved a range of four metres. With a single lens at the Transmitter, it achieved a range of 15 metres. In theory, therefore, with the use of two lenses, it should achieve a range of fifty metres using a single cheap, ultrabright l.e.d. The problem with similar analogue circuits is that these depend on a light beam of continuously variable intensity. What happens in this case is that, over distance, the subtler nuances of the light beam are lost – and with them the intelligibility of the voice. Transmitting a voice in binary form has the advantage of always transmitting at full intensity. This means that even the weakest nuances of a voice will reach the Receiver as strongly as the rest. Lighting The Way Besides being good fun, communicating via a light-beam may have certain advantages over other methods of transmission. It requires no wires, it needs no radio license, it is very cheap to implement, and it is all but impossible for anyone to eavesdrop on a transmission. Not only this, but the PROJECT may also be used with fibre optic cable or a laser (at a price)s.

DIGITAL LOCK

Digital locks have many advantages over their conventional mechanical counterparts and perhaps the greatest is that no keys are required. Over the years many circuits for digital locks have been designed, usually based on special custom integrated circuits or even microprocessors with many features, such as built-in alarms to detect multiple incorrect entries by someone trying to break the code. It is possible, though, to construct a simple yet effective combination lock based on a single easily available counter integrated circuit. The design can be further simplified by defining the combination by means of wire links instead of storing it in a memorydevice. Whilst this makes it more difficult to change the code, it is unlikely that this will be problem. A coded lock circuit can also find many applications apart from the obvious one of its use in a door. By using the circuit to control a relay, the circuit could be used to switch on the supply to a piece of equipment, for instance, thus preventing its unauthorised use.

ROOM THERMOMETER

ROOM THERMOMETER

ELECTRONIC thermometers have all but replaced the old mercury or alcohol-in-glass types in most applications.The electronic types can usually respond much faster to temperature changes, and also allow the display to beremote from the sensor, allowing greater flexibility in use. They can also be more accurate and, depending on the sensor, can be used over greater temperature ranges. It has to be said, though, that the thermometer design described here is not the last word either in range or accuracy (perhaps a temperature indicator would be a more apt description), as it is intended to display the temperature of a room where neither of these attributes is particularly important. Here the range is limited to 10°C and this is displayed in one degree steps on ten l.e.d.s. These are normally turned off to save power, but may be turned on by means of a pushswitch when a reading is required. Basic Operation All electronic thermometers contain a sensor which converts a change in temperature to a change in some electrical property such as resistance, output current etc. In most cases, this is converted to a voltage which is then further processed (amplified, etc.) before being fed to some sort of analogue-to-digital converter (ADC) and output to a digital display. Of the many different sensors available, a thermistor is used here for simplicity.

KITCHEN TIMER

KITCHEN TIMER

Constructional Project Kitchen Timer THERE are many simple operations in a kitchen which require short timing intervals without constant attention, and simply needing a signal to alert the user that the operation has been completed. Such devices are available in the shops, including electronic timers featuring crystal controlled timing with l.c.d. displays. But if such sophistication is not really needed, it can still be almost as cheap to build your own, and much more fun! The timer described here can be set for periods of up to nine minutes in one minute increments, but a simple component change can result in, say, a 4·5 minute period in 30 second increments, or 18 minutes in two minute increments. Longer periods are impractical unless the timing is repeated or the clock oscillator redesigned. The elapsed time is displayed to the nearest minute and an alarm indicates the end of the period.

Multicore Cable Tester

Multicore Cable Tester

THE number of fairly complex multicore cables in the home and the workshop is steadily increasing. The workshop PC brings with it a printer, keyboard, mouse and monitor, possibly a network connection and probably a modem line. All of these items require a dedicated connector and a multicore cable to connect it all together. Buying commercially-made leads can be expensive, and even then, you may not be able to get exactly what you require and have to manufacture your own; with the attendant doubt that all is wired, and wired correctly! Testing these leads can be confusing, especially if there are several to make up of the same type. Commercially manufactured leads are just as prone to damage, kinking, and connector failure as those we make ourselves, and if you count up the number of leads that surround us in the home and at work, the result can be quite surprising. If The cable is quite long and checking with a multimeter is simply not an easy option. This tester allows easy identification and testing of multicore cables in a variety of situations so long as at least two cores are connected. It offers quicker testing than traditional continuity methods, using l.e.d. indication and sound to check continuity and correct connections in cables. There is also a “quick check” for crossover wired cables. The unit is designed to test cables having up to eight cores, with cables having more than eight conductors being split into groups of tests. However, eight cores is sufficient for most, including: 1. Ethernet cables 2. Audio cables 3. Keyboard and mouse extension leads 4. Computer monitor cables 5. Modem/serial leads 6. USB cables, etc. The unit will: 1 Identify a cable 2. Check continuity of all cores 3. Identify a “crossover” type cable

Parking Radar

Parking Radar

Presented now is a little unit that is both inexpensive and easily fitted to any car and should help to prevent expensive mishaps. The unit uses ultrasonics to determine the distance to an obstruction, the presence of which is indicated initially by an L.E.D. As the distance is reduced, a sounder emits a tone that rises in pitch to give a rough indication of the distance before impact. As well as its intended use, this unit could also be suitable for a blind or partially sighted person to indicate the presence of obstacles in their path. All radars operate on more or less the same principle – a signal is transmitted which bounces back from the target to a receiver, which measures the time taken for the echo to return. For long distance radar, radio frequency signals are used, but for short range applications (up to a few tens of metres) ultrasonics offer a simpler method.

Driver alert

Driver alert

REACTION times are affected by many factors, such as alcohol, drugs, general medical conditions and tiredness. It seemed a good idea, therefore, to devise a circuit to test reaction times. Unfortunately, during extensive tests using volunteers who consumed large quantities of beer, it was found that sheer reaction time is not greatly affected – particularly if the person is poised waiting for something to happen. This is quite unlike driving a car, where anything can happen at any time, and so concentration and thinking times are critical. Using a dual 7-segment display, the project described here tests the “driver’s” ability to concentrate, think and react. The beer tests now provided more dramatic results. How thinking/reaction time increased progressively with the number of cans of lager consumed .A mobile phone test was also devised, and, surprisingly it was found that speaking on a mobile phone, including a hands-free unit gave similar results to drinking four cans of lager. The results for several people are also illustrated. The Driver Alert allows drivers to test their own thinking/reaction time. It consists of three buttons labelled 1, 2 and 3, three lights and a dual 7-segment display A number 1 appears, meaning “Test 1”. After a random delay a single l.e.d. lights up in any position, or two lights in any position, or all three lights appear. You have to press the appropriate button according to the number of lights that appear. Since the lights may be in any position, a little thought is needed to press the correct button, and it is mainly this thinking time which is affected by alcohol etc.

INFRA RED CONTROL FOR PC

This is unique project designed to to control the PC functions using any remote controls that comes with house hold equipments such as tv,vcr dvd etc.

you can play a song ,open a document watch movie,or conduct slide shows on PC.Receiver circuit is connected on the PC COM port . KIT COMES ALONG WITH V.B. EXAMPLE CODES FOR SLIDE SHOW ON CD.

Line follower Robot

Line follower Robot

This robot will follow the black line or it will only move on the black road ,and it will never go out of road.It will stop in case obsticle comes in it's passage. Based on 8051 We have fixed two light sensors on fore side on the robo. The principle of sensors is that black colour will normally observe the light where other colours will normally reflects the lights light source is fixed down ward Ld1 ,a white led reflected light will fall on the ldr if the light is more the resistance of the ldr is normally low and transister remains in cutoff state When the robo moves on the black road , the light reflected is less and the ldr resistance is increasd, vr1 forms a potential driver along with ldr due to increase in resistance the base voltage on t1 will rise to conductionlevel and transister will go into on (conduction)state. Resulting it’s collector which was getting high logic from the default microcontroller pin will become low. This low logic detection confirms that the robo is on the black road if the robo is our of the black road this logic will become high and it indicates off-road. Depending upon the left or right sensor robo will move towards right or left direction in order to stay on road out put from both the sensors shoul be low when the robo is on the road....

HOME APPLIANCE CONTROL THROUGH PC

This is unique project designed to Control Home appliances through your computer, using

1. Hyper Terminal 2. Dialup network 3. Internet, using web applications 4. Through s.m.s.

Application area: the project can be used for various application wherever you require control using pc. 1 hotel power management 2.street light management 3.home automation 4.load shedding 5. High voltage grid control 6. Industrial automation 7.electro,hydrolic and pneumatic valve control 8. Robotic control and many more ....

No pc software is required if you are using Hyperterminal.How to use hyperterminal is explained in this project.

R.F.I.D FOR DIFFERENT APPLICATIONS

R.F.I.D FOR DIFFERENT APPLICATIONS

OVERVIEW: Radio frequency identification has been in use since very long time

You must have seen on discovery channel that the people used to connect a tag to animal and then they used to monitor their location so that they can study their behaviour. With the advancement of technology same rfid’s are becoming popular, modern rfid consists of a transmitter and a receiver. Transmitter dose not require any power supply it receives it,s power solely from it,s antenna coil attached to it.at I a very small antenna coil and has a very low transmitting range. Transmitter range is within the range of few mm.receiver will have a display device normally a lcd and a data port from where data can be sent to pc. Advanced receivers have Real time clock with enough memory to store the data and later on the data can be transmitted to pc when it’s memory is full.

Most of the commercial available rfid tags and receiver are costly and is not possible by students to develop such devices , even components required are not easily available.

I have designed a rfid device on the similar principals. My transmitter and receiver both are based on intel’s popular controller 8051 family of controller. I have used at89c2051 microcontroller.

Application area: 1 Bus route application. 2 Attendence register 3 Inventry application 4 Security application 5 Rfid can be given to any living or non living thing which need accountabilitry.

TELEPHONE CALLS LOGGER ( LOGS ALL incoming and outgoing CALLS TO PC)

My purpose of designing of this project is to make people accountable. You call up any public office , most of the time, people are not available on phone or they ignore it.You must have seen an english movie, where a vilian is behind a person ,the person is runing here and there to protect himeself and finally reaches a public telephone booth, , makes a call to police, by the time he could speak any word, the vilian comes behind and stabs him or shoots him and you see the phone drops down from his hand and a pool of blood is shown, What heppend next ,you find that police arrives in time and The person is taken to hospital ,his life is saved.How dose the police know that the panic call came from which location.?

PANIC ID/ CALL ID LOGGER

The concept is very simple every police station has complete data base of all the telephone numbers along with the complete details of the owner ,the movement any calls comes to police station, they get complete details of that phone number, so even you are not able to speak to him ,he will call back to you and if not responded, he will emmidately inform the nearest police on petrol about the call. Thet is how the police in most of the advanced country functions. This projects is designed to monitor all incoming and outgoing calls from your landline telephone, and each calls it also sends to pc for logging you can detect any misuse of your telephone line just connect this device in parallel to your telephone line . silently this device will keep doing its job . you can develop pc based software to put time stamp on each call .police department and hospitals can trace any panic call and take necessary action.I will take one more case ,about few years back Mumbai ,s leading MTNL company which provides land line telephone service. If your telephone goes bad or any other problem with your line, the complaint department used to write your complaint manually,the telephones used to remain dead for many days. If you wanted same day service, just bribe the line man he will do it same day. This was my experience may be yours too. See now a days every call is logged on the computer and complaint number is also generated your phone get repaired on the first day of your complaint y because, the data logged on computer can be seen by any senior official. and every one of them are accountable now . Why cant we make the other departments also accountable such as MAHA NAGAR PALIKA ,PUBLIC HEALTH DEPARTMENTS,SANETARY DEPARTMENTS,WATER DEPARTMENTS,POLICE STATIONS, AMBULENCE SERVICES,FIRE BRIGADES,ELECTRICITY DEPARTMENT .PUBLIC TRANSPORT SERVICES,ANTI-CURRPTION BUREO,CONSUMER REDRESSAL FORUM, RTO OFFICE, AND MANY MORE…… Then is project is most suitable for these types of applications.

DC motor speed control from PC Suitable for Robotic arm

DC motor speed control from PC

Suitable for Robotic arm

INEXPENSIVE d.c. motors are often used by model-makers, not only for model locomotives and racing cars but in robots of all kinds. They may also be used for driving non-mobile models made from anything from cardboard to Meccano. This project controls a small 6V d.c.motor, but can be used for 12V or highervoltage d.c. motors as well. The circuit controls both the speed and the direction of the motor. There is a wide range of cheap low-voltage motors available, running at maximum no-load speeds ranging from 3600 r.p.m. to 18,000 r.p.m. or more. Torque may be anything between 3g-cm for the cheaper versions and over 60g-cm for the slightly more expensive motors. Many applications require slower speeds with correspondingly greater torque, and there are several different plastic gearboxes available for the model maker to use. There are also motor-driven devices such as cooling fans and water pumps that can be controlled by this project. If controlling motors is of no interest to you, perhaps you might like to use the circuit for controlling the brightness of a filament This D.C. Motor Controller project It is possible to control the speed of a motor by simply wiring a resistor in series with it. Apart from the inefficiency of such a system, there is the need for a heavy-duty variable resistor (potentiometer). A typical d.c. motor requires several hundred milliamps to drive it. If the motor is taking, say, 300mA and the variable resistor is dropping, say, 3V, the power dissipated in the resistor is 0·9W. The typical variable potentiometer is rated at only 0·25W, so something much more robust is required, costing three or more times as much.Another factor is that motors do not run well on less than their full rated voltage. They fail to start turning when current is switched on and have a tendency to stall when extra load is applied.

We all know that ac motors are normally constant speed motors Vriable speed ac drives uses very complex circuitory because the ac motor speed is varied by the frequency variation.and is not quite easy.Stepper motor gives calculated angle of rotation they take number of steps in one revolution they canot be stopped inbetween the step. Also they are not constant running motors their use is limited to the area where you wanted a calculated steps to be taken such as priners, plotters, and other similar applications. Dc motors are widely used in industry where wide range of variable speed is required. Their application area is very wide : textile , petrochemical, medical electronics,consumer electronics, submarines,aircrafts, military equipments,setallites vehicles, rockets, trains,trams, non pollution vehicles,cars, robotics and the list is non ending. In a nut shell where a precission speed control is required, dc motor is required. The circuit designed using atmel 89c51 family of microcontroller the speed is controlled using pwm techniques pwm pulse is the on off ( low or high pulse) given to the motor driver circuit.

DC motor speed control using radio link SUIATBLE FOR ROBOTIC ARM

DC motor speed control using radio link SUIATBLE FOR ROBOTIC ARM

INEXPENSIVE d.c. motors are often used by model-makers, not only for model locomotives and racing cars but in robots of all kinds. They may also be used for driving non-mobile models made from anything from cardboard to Meccano.This project controls a small 6V d.c.motor, but can be used for 12V or highervoltage d.c. motors as well. The circuit controls both the speed and the direction of the motor. There is a wide range of cheap low-voltage motors available, running at maximum no-load speeds ranging from 3600 r.p.m. to 18,000 r.p.m. or more. Torque may be anything between 3g-cm for the cheaper versions and over 60g-cm for the slightly more expensive motors. Many applications require slower speeds with correspondingly greater torque, and there are several different plastic gearboxes available for the model maker to use. There are also motor-driven devices such as cooling fans and water pumps that can be controlled by this project. If controlling motors is of no interest to you, perhaps you might like to use the circuit for controlling the brightness of a filament This D.C. Motor Controller project It is possible to control the speed of a motor by simply wiring a resistor in series with it. Apart from the inefficiency of such a system, there is the need for a heavy-duty variable resistor (potentiometer). A typical d.c. motor requires several hundred milliamps to drive it. If the motor is taking, say, 300mA and the variable resistor is dropping, say, 3V, the power dissipated in the resistor is 0·9W. The typical variable potentiometer is rated at only 0·25W, so something much more robust isrequired, costing three or more times as much.Another factor is that motors do not run well on less than their full rated voltage. They fail to start turning when current isswitched on and have a tendency to stall when extra load is applied. We all know that ac motors are normally constant speed motors Vriable speed ac drives uses very complex circuitory because the ac motor speed is varied by the frequency variation.and is not quite easy. Stepper motor gives calculated angle of rotation they take number of steps in one revolution they canot be stopped inbetween the step. Also they are not constant running motors their use is limited to the area where you wanted a calculated steps to be taken such as priners, plotters, and other similar applications. Dc motors are widely used in industry where wide range of variable speed is required. Their application area is very wide : textile , petrochemical, medical electronics,consumer electronics, submarines,aircrafts, military equipments,setallites vehicles, rockets, trains,trams, non pollution vehicles,cars, robotics and the list is non ending. In a nut shell where a precission speed control is required, dc motor is required.

POWER HOUSE MONITORING USING RADIO-LINK

POWER HOUSE MONITORING USING RADIO-LINK

Power house monitoring is done on the receiver part fitted with lcd.Following parameters monitored are ,high voltage,over load, no-voltage or temperature high.,these paremeters are transmitted by transmitter .audio and visual alarm comes on both the places ,alarms have to be reset from both the places.receiver will also display the alarming condition.these conditions also logged on to pc through serial port.