Friday, April 15, 2011

Wireless Protable Intercom Voice Activated

Chamberlain wireless portable inte- Provides convenient and expandablemunication for your home- Advanced features include voice activation and monitor mode- Crystal clear secure 900 MHz digitalmunication- 1000 Foot rangeCHNLS2
Technical Details
* This wireless intercom system has an amazing 1000 ft.
* This portable wireless intercom system is fully expandable to an unlimited number of intercom stations that share 4 Channels.
* The Monitor Mode features the most advanced Voice Operated Switch (VOX) allowing you to customize sensitivity settings
* Secure 900 MHZ radio link. Compact size- each intercom unit measures less than 4″x5.5″x2″.

Low Cost Burglar Alarm For Boats

This low-cost burglar alarm employs a 12V strobe light and a truck reversing horn as the visible and audible alarm outputs while the alarm itself is a 12V horn relay and some pressure mat switches. This simple approach has the benefit that the alarm continues to operate even if the entry point is immediately closed and it draws no current while in the armed condition. To make it independent of the boat supply it runs from a single 12V or two 6V alkaline lantern batteries connected in series. These should last well in excess of two years. An advantage of a lantern battery is that it will last less than an hour while powering the alarm in its active role.
This means the alarm system will not seriously contravene noise pollution laws. If there are very strict noise regulations in your area, you can fit an alarm timer, available from some electronic shops, in the circuit between the battery positive and the key switch. The key switch can be installed in the cockpit bulkhead and connects to two normally open (NO) switches wired in parallel. One switch is a pressure mat placed on the cockpit floor near the entry, underneath a suitable piece of carpet or pliable cover. If a pressure mat is unsuitable, the main entry can be protected by a mechanical switch such as an automobile boot lid or door courtesy light switch.
The second switch can be used to protect against entry through a forward hatch or second wheelhouse door. Any number of normally open (NO) switches can be installed in this system, all wired in parallel. If the alarm is tripped, the relay closes and latches on due to the wiring of its contacts and the horn and strobe light are powered. The suggested truck reversing horn is the Hella 6023 intermittent reversing buzzer which has an 85dB sound level and a current drain of 0.9A at 12V. The suggested strobe is a Hella 1657 which has an amber lens in a weatherproof housing. This strobe flashes about once per second and the current drain at 12V is 0.25A. The strobe can be installed outside on deck or in the main cabin where its flash will be seen through most ports and windows. Wiring to both the warning horn and strobe light should be concealed.
Author: Dave Jeanes – Copyright: Silicon Chip Electronics

Fridge door Alarm

Beeps if you leave open the door over 20 seconds
3V battery operation, simple circuitry

This circuit, enclosed into a small box, is placed in the fridge near the lamp (if any) or the opening. With the door closed the interior of the fridge is in the dark, the photo resistor R2 presents a high resistance (>200K) thus clamping IC1 by holding pin 12 high. When a beam of light enters from the opening, or the fridge lamp illuminates, the photo resistor lowers its resistance (<2K), pin 12 goes low, IC1 starts counting and, after a preset delay (20 seconds in this case) the piezo sounder beeps for 20 sec. then stops for the same lapse of time and the cycle repeats until the fridge door closes. D2 connected to pin 6 of IC1 allows the piezo sounder beeping 3 times per second.
Parts:
R1____________10K 1/4W Resistor
R2___________Photo resistor (any type)
R3,R4________100K 1/4W Resistors
C1____________10nF 63V Polyester Capacitor
C2___________100µF 25V Electrolytic Capacitor
D1,D2_______1N4148 75V 150mA Diodes
IC1___________4060 14 stage ripple counter and oscillator IC
Q1___________BC337 45V 800mA NPN Transistor
BZ1__________Piezo sounder (incorporating 3KHz oscillator)
SW1__________Miniature SPST slide Switch
B1___________3V Battery (2 AA 1.5V Cells in series)

12V Battery Charger

Solid state two color LED indicates stage of charger; a quick connect harness for use in hard to reach areas
Perfect for all lead-acid, flooded or sealed maintenance free batteries (AGM and gel cell)
Complete 4-step charging program (initialization, bulk charge, absorption mode and float mode) that maintains batteries at full charge without overcharging via its 4-step charging system
Automatically switches to float/maintenance mode voltage after fully charging the battery
Temperature compensated to ensure optimum charge voltage according to ambient temperature, and spark proof and reverse polarity protected; 10-year limited warranty

Simple Battery Isolator

This circuit is even simpler and employs a 6V feed from one of the stator connections on the vehicle’s alternator. This is connected to a 6V automotive relay (RLY1) which controls a Continuous Duty Solenoid (RLY2). This solenoid electrically connects or isolates the batteries. When the engine is started and the alternator stator voltage rises, the 6V relay turns on. This turns on the Continuous Duty Solenoid to connect the two batteries in parallel. As long as the engine is running, the vehicle’s alternator will maintain charge in both batteries.
When the engine is shut down, the alternator stator voltage drops and the Continuous Duty Solenoid switches off, thus isolating the second battery from the vehicle’s electrical system. Provided that camping accessories are only connected to the second battery, the main battery should never discharge. Because the concept is entirely dependent upon the alternator’s stator output voltage, you cannot forget to turn the system on or off as it happens automatically.
Copyright: Silicon Chip Electronic

Easy dry cell charger with CMOS IC 4011

The dry cell charger circuit can be fully charged about 12 hours.When used with a 9 volt supply,the equipments in the circuit for the AA type cell.When using the C and D type cell, should reduce the value of the resistance Rx to be 68 ohms.In charge of the cell, you should not be charged to the same series, may cause cell damage is fully charged.
If the cell voltage is below 1.6 volt,The compared circuit to leave the square wave oscillator by the CMOS gate,then the transistor made a charge until the cell voltage is 1.6 volt.The comparison circuit will cut the charging LED blinks, notice prevents over-charging.

alarm with countdown timer

This circuit is IC implementation schedule. No. 555 applied with IC number LM3905.By the IC to the number 555 are the circuits Stable multi-vibrator. How often do produce it.This frequency is then forwarded to the scheduling with the integrated circuit number LM3905.
When entering the power supply circuit IC1 No. 555. To be atable multivibrator circuit. Produce about 0.5 hertz frequency out.The R1, VR1, R2 and C1 determine the frequency.The output pin 3 will be out of a square wave LED1 will be lit.The signal is a negative split.and LED2 will be lit during a split positive signal.This will flash alternately throughout the duration of scheduled. IC2 is a timer IC.Includes VR2, R6 and C3.The setup time will be how long it can adjust the VR2.And while time is the output pin 7 of IC2 pin voltage will be 0 volt.And when it’s time to set the output pin 7 will have a positive voltage to Buzzer beeps out the rhythmic flashing of the LED.

Source : Countdown timer with alarm


Simple Wireless Security Alarm For Car

Alarm circuit is functioning as a car wireless security alarm. Yes, this is an FM radio-controlled anti-theft alarm. This alarm can be used on any vehicle that has a DC power supply 6-12V.
Alarm circuit system is divided into two parts, the transmitter unit and receiver unit. Transmitter unit is working on the range of VHF Band II, exactly at a frequency of 88-108 MHz. This transmitter is a miniature FM transmitter that is installed in vehicles at night while parked in the car porch or car park.

Simple Car Wireless Security Alarm Schematic
The receiver is a single IC-based FM radio module, CXA1019, kept inside. Receiver tuned frequency matches the transmitter. CXA1019 IC is widely available in the market with an affordable price, or you can find replacement parts CXA1191.
How This Car Wireless Secuity Alarm Works
When the transmitter is on and the signals are being received by the FM radio receiver, no hissing noise is available at the output of the receiver. Thus transistor T2 (BC548) does not conduct. This result in the relay driver transistor T3 getting its forward base bias via 10k resistor R5 and the relay gets energized.
When an intruder tries to drive the car and takes it a few metres away from the car porch, the radio link between the car (transmitter) and alarm (receiver) is broken. As a result FM radio module generates hissing noise.
Hissing AC signals are coupled to relay switching circuit via an audio transformer. These AC signals are rectified and filtered by diode D1 and capacitor C8, and the resulting positive DC voltage provides a forward bias to transistor T2. Thus transistor T2 conducts, and it pulls the base of relay driver transistor T3 to ground level. The relay thus gets de-activated and the alarm connected via N/C contacts of relay is switched on.
If, by chance, the intruder finds out about the wireless security alarm and disconnects the transmitter from battery, still remote alarm remains activated because in the absence of signal, the receiver continues to produce hissing noise at its output. So the burglar alarm is fool-proof and highly reliable.

50 THINGS EVERYONE SHOULD KNOW


The word "queue" is the only word in the English language that is still pronounced the same way when the last four letters are removed.Beetles taste like apples, wasps like pine nuts, and worms  like fried bacon.
Of all the words in the English language, the word 'set' has the most definitions!
What is called a "French kiss" in the English speaking world is known as an "English kiss" in France.
"Almost" is the longest word in the English language with all the letters in alphabetical order.
"Rhythm" is the longest English word without a vowel.

In 1386, a pig in France was executed by public hanging for the murder of a child

A cockroach can live several weeks with its head cut off!

Human thigh bones are stronger than concrete.

You can't kill yourself by holding your breath

There is a city called Rome on every continent.

It's against the law to have a pet dog in Iceland!

Your heart beats over 100,000 times a day!

Horatio Nelson, one of England's most illustrious admirals was throughout his life, never able to find a cure for his sea-sickness.
The skeleton of Jeremy Bentham is present at all important meetings of the University of London
Right handed people live, on average, nine years longer than left-handed people

Your ribs move about 5 million times a year, everytime you breathe!

The elephant is the only mammal  that can't jump!

One quarter of the bones in your body, are in your feet!

Like fingerprints, everyone's tongue print is different!

The first known transfusion of blood was performed as early as 1667, when Jean-Baptiste, transfused two pints of blood from a sheep to a young man

Fingernails grow nearly 4 times faster than toenails!

Most dust particles in your house are made from dead skin!

The present population of 5 billion plus people of the world is predicted to become 15 billion by 2080.

Women blink nearly twice as much as men.Adolf Hitler was a vegetarian, and had only ONE testicle.


Honey is the only food that does not spoil. Honey found in the tombs of Egyptian pharaohs has been tasted by archaeologists and found edible.

Months that begin on a Sunday will always have a "Friday the 13th."

Coca-Cola would be green if colouring weren’t added to it.

On average a hedgehog's  heart beats 300 times a minute.

More people are killed each year from bees than from snakes.

The average lead pencil will draw a line 35 miles long or write approximately 50,000 English words.
More people are allergic to cow's milk than any other food.

Camels have three eyelids to protect themselves from blowing sand.

The placement of a donkey's eyes in its' heads enables it to see all four feet at all times!

The six official languages of the United Nations are: English, French, Arabic, Chinese, Russian and Spanish.
Earth is the only planet not named after a god.

It's against the law to burp, or sneeze in a church in Nebraska, USA.

You're born with 300 bones, but by the time you become an adult, you only have 206.

Some worms will eat themselves if they can't find any food!

Dolphins sleep with one eye open!


It is impossible to sneeze with your eyes open

The worlds oldest piece of chewing gum is 9000 years old!
The longest recorded flight  of a chicken is 13 seconds
Queen Elizabeth I regarded herself as a paragon of cleanliness. She declared that she bathed once every three months, whether she needed it or not
Slugs have 4 noses.

Owls are the only birds who can see the colour blue.

A man named Charles Osborne had the hiccups for 69 years!

A giraffe can clean its ears with its 21-inch tongue!

The average person laughs 10 times a day!
An ostrich's eye is bigger than its brain

Amazing Facts about India


Amazing Facts about India and Indians!
  1. India is the world's largest, oldest, continuous civilization.
  2. India never invaded any country in her last 10000 years of history.
  3. India is the world's largest democracy.
  4. Varanasi, also known as Benares, was called "the ancient city" when Lord Buddha visited it in 500 B.C.E, and is the oldest, continuously inhabited city in the world today.
  5. India invented the Number System. Zero was invented by Aryabhatta.
  6. The World's first university was established in Takshashila in 700BC. More than 10,500 students from all over the world studied more than 60 subjects. The University of Nalanda built in the 4th century BC was one of the greatest achievements of ancient India in the field of education.
  7. Sanskrit is the mother of all the European languages. Sanskrit is the most suitable language for computer software - a report in Forbes magazine, July 1987.
  8. Ayurveda is the earliest school of medicine known to humans. Charaka, the father of medicine consolidated Ayurveda 2500 years ago. Today Ayurveda is fast regaining its rightful place in our civilization.
  9. Although modern images of India often show poverty and lack of development, India was the richest country on earth until the time of British invasion in the early 17th Century. Christopher Columbus was attracted by India's wealth.
  10. The art of Navigation was born in the river Sindhu 6000 years ago. The very word Navigation is derived from the Sanskrit word NAVGATIH. The word navy is also derived from Sanskrit 'Nou'.
  11. Bhaskaracharya calculated the time taken by the earth to orbit the sun hundreds of years before the astronomer Smart. Time taken by earth to orbit the sun: (5th century) 365.258756484 days.
  12. The value of pi was first calculated by Budhayana, and he explained the concept of what is known as the Pythagorean Theorem. He discovered this in the 6th century long before the European mathematicians.
  13. Algebra, trigonometry and calculus came from India. Quadratic equations were by Sridharacharya in the 11th century. The largest numbers the Greeks and the Romans used were 106 whereas Hindus used numbers as big as 10**53(10 to the power of 53) with specific names as early as 5000 BCE during the Vedic period. Even today, the largest used number is Tera 10**12(10 to the power of 12).
  14. IEEE has proved what has been a century old suspicion in the world scientific community that the pioneer of wireless communication was Prof. Jagdish Boseand not Marconi.
  15. The earliest reservoir and dam for irrigation was built in Saurashtra.
  16. According to Saka King Rudradaman I of 150 CE a beautiful lake calledSudarshana was constructed on the hills of Raivataka during Chandragupta Maurya's time.
  17. Chess (Shataranja or AshtaPada) was invented in India.
  18. Sushruta is the father of surgery. 2600 years ago he and health scientists of his time conducted complicated surgeries like cesareans, cataract, artificial limbs, fractures, urinary stones and even plastic surgery and brain surgery. Usage of anesthesia was well known in ancient India. Over 125 surgical equipment were used. Deep knowledge of anatomy, physiology, etiology, embryology, digestion, metabolism, genetics and immunity is also found in many texts.
  19. When many cultures were only nomadic forest dwellers over 5000 years ago, Indians established Harappan culture in Sindhu Valley (Indus Valley Civilization).
  20. The four religions born in India, Hinduism, Buddhism, Jainism, and Sikhism, are followed by 25% of the world's population.
  21. The place value system, the decimal system was developed in India in 100 BC.
  22. India is one of the few countries in the World, which gained independence without violence.
  23. India has the second largest pool of Scientists and Engineers in the World.
  24. India is the largest English speaking nation in the world.
  25. India is the only country other than US and Japan, to have built a super computer indigenously.
Following facts were published in a German Magazine which deals with world history. (I couldn't find out the name of that German Magazine, if you find please let me know.)
  • 38% of Doctors in America are Indians.
  • 12% of Scientists in America are Indians.
  • 36% of NASA employees are Indians.
  • 34% of Microsoft employees are Indians.
  • 28% of IBM employees are Indians.
  • 17% of Intel employees are Indians.
  • 13% of Xerox employees are Indians.
Famous Quotes on India (by non-Indians)
  • Albert Einstein said: We owe a lot to the Indians, who taught us how to count, without which no worthwhile scientific discovery could have been made.
  • Mark Twain said: India is, the cradle of the human race, the birthplace of human speech, the mother of history, the grandmother of legend, and the great grand mother of tradition. Our most valuable and most instructive materials in the history of man are treasured up in India only.
  • French scholar Romain Rolland said: If there is one place on the face of earth where all the dreams of living men have found a home from the very earliest days when man began the dream of existence, it is India.
  • Hu Shih, former Ambassador of China to USA said: India conquered and dominated China culturally for 20 centuries without ever having to send a single soldier across her border.