Who is the inventor of microwave

He helped develop the first gaseous rectifier tube, which made the radio a plug-in appliance. Spencer was a leading authority in the field of microwave energy and high frequency devices, and held patents for inventions. His inventions included the application of microwave energy to medical diathermy and the Radarange oven that cooks food electronically. As a result of inventions made in the field of radar during this time Dr. Spencer was awarded the U. Spencer also developed the special electronic tubes that made possible the proximity fuses introduced in World War II.

On this day in , Percy Spencer, the self-taught scientist who discovered the power of microwave technology, was born. With an endlessly curious mind, Spencer spent much of his early life figuring out how things worked. Orphaned as a small boy, Spencer had little schooling before he entered the workforce.

But a fascination with electricity and nights of studying on his own led to a job with a new firm in Cambridge — Raytheon. During World War II, Spencer and his co-workers developed technology that gave the Allies a critical edge in radar detection.

Later, a set of simple experiments based on everyday experiences resulted in the first microwave oven, the pound, five-foot-tall RadarRange. His lack of formal education meant that he had to teach himself trigonometry, calculus, chemistry, physics, and metallurgy at night.

Percy Spencer, a New England farm boy who never completed grammar school, grew up to be one of the world's most successful and respected electrical engineers. One colleague with a degree from M. Percy doesn't know what can't be done. Spencer was born in Howland, Maine. Military Enigma machines also had a plugboard, which swapped specific pairs of letters both at the keyboard input and at the output lamps.

The rotor-machine era finally ended around , with the advent of electronic and software encryption, although a Soviet rotor machine called Fialka was deployed well into the s. The HX pushed the envelope of cryptography. For starters it has a bank of nine removable rotors. The unit I acquired has a cast-aluminum base, a power supply, a motor drive, a mechanical keyboard, and a paper-tape printer designed to display both the input text and either the enciphered or deciphered text.

In encryption mode, the operator types in the plaintext, and the encrypted message is printed out on the paper tape. Each plaintext letter typed into the keyboard is scrambled according to the many permutations of the rotor bank and modificator to yield the ciphertext letter. In decryption mode, the process is reversed. The user types in the encrypted message, and both the original and decrypted message are printed, character by character and side by side, on the paper tape. While encrypting or decrypting a message, the HX prints both the original and the encrypted message on paper tape.

The blue wheels are made of an absorbent foam that soaks up ink and applies it to the embossed print wheels. Beneath the nine rotors on the HX are nine keys that unlock each rotor to set the initial rotor position before starting a message. That initial position is an important component of the cryptographic key. To begin encrypting a message, you select nine rotors out of 12 and set up the rotor pins that determine the stepping motion of the rotors relative to one another.

Then you place the rotors in the machine in a specific order from right to left, and set each rotor in a specific starting position. Finally, you set each of the 41 modificator switches to a previously determined position. To decrypt the message, those same rotors and settings, along with those of the modificator, must be re-created in the receiver's identical machine.

All of these positions, wirings, and settings of the rotors and of the modificator are collectively known as the key. The HX includes, in addition to the hand crank, a nickel-cadmium battery to run the rotor circuit and printer if no mains power is available.

A volt DC linear power supply runs the motor and printer and charges the battery. The precision volt motor runs continuously, driving the rotors and the printer shaft through a reduction gear and a clutch. Pressing a key on the keyboard releases a mechanical stop, so the gear drive propels the machine through a single cycle, turning the shaft, which advances the rotors and prints a character. The printer has two embossed alphabet wheels, which rotate on each keystroke and are stopped at the desired letter by four solenoids and ratchet mechanisms.

Fed by output from the rotor bank and keyboard, mechanical shaft encoders sense the position of the alphabet printing wheels and stop the rotation at the required letter. Each alphabet wheel has its own encoder. One set prints the input on the left half of the paper tape; the other prints the output on the right side of the tape.

After an alphabet wheel is stopped, a cam releases a print hammer, which strikes the paper tape against the embossed letter. At the last step the motor advances the paper tape, completing the cycle, and the machine is ready for the next letter. As I began restoring the HX, I quickly realized the scope of the challenge. The plastic gears and rubber parts had deteriorated, to the point where the mechanical stress of motor-driven operation could easily destroy them.

Replacement parts don't exist, so I had to build such parts myself. After cleaning and lubricating the machine, I struck a few keys on the keyboard. I was delighted to see that all nine cipher rotors turned and the machine printed a few characters on the paper tape. But the printout was intermittently blank and distorted. I replaced the corroded nickel-cadmium battery and rewired the power transformer, then gradually applied AC power.

To my amazement, the motor, rotors, and the printer worked for a few keystrokes. But suddenly there was a crash of gnashing gears, and broken plastic bits flew out of the machine.

Printing stopped altogether, and my heartbeat nearly did too. I decided to disassemble the HX into modules: The rotor bank lifted off, then the printer.

The base contains the keyboard, power supply, and controls. These snubbers had disintegrated. Also, the foam disks that ink the alphabet wheels were decomposing, and gooey bits were clogging the alphabet wheels.

I made some happy, serendipitous finds. To rebuild the broken printer parts, I needed a dense rubber tube. I discovered that a widely available neoprene vacuum hose worked perfectly. Using a drill press and a steel rod as a mandrel, I cut the hose into precise, millimeter sections.

But the space deep within the printer, where the plastic snubbers are supposed to be, was blocked by many shafts and levers, which seemed too risky to remove and replace. So I used right-angle long-nosed pliers and dental tools to maneuver the new snubbers under the mechanism.

After hours of deft surgery, I managed to install the snubbers. The HX has nine rotors and also uses a technique called reinjection. Each rotor has a set of conductors that connect each and every electrical contact on one side of the rotor with a different contact on the other side.

For every rotor the pattern of these connections is unique. When the operator strikes a key on the keyboard, representing one of 26 letters, current travels through the set of nine rotors twice, once in each direction, and then through a separate set of 15 rotor contacts at least two times.

This reinjection technique greatly increases the complexity of the cipher. The ink wheels were made of an unusual porous foam. I tested many replacement materials, settling finally on a dense blue foam cylinder. Alas, it had a smooth, closed-cell surface that would not absorb ink, so I abraded the surface with rough sandpaper. After a few more such fixes, I faced just one more snafu: a bad paper-tape jam.

I had loaded a new roll of paper tape, but I did not realize that this roll had a slightly smaller core. The tape seized, tore, and jammed under the alphabet wheels, deeply buried and inaccessible. I was stymied—but then made a wonderful discovery. Other food industry establishments used microwaves for roasting coffee beans and peanuts, defrosting and precooking meat, and even shucking oysters. Other industries also found uses for microwave heating.

Microwave ovens are also used to dry cork, ceramics, paper, leather, tobacco, textiles, pencils, flowers, wet books and match heads, according to Gallawa. Raytheon acquired Amana Refrigeration in , and two years later, the Amana Radarange, which could fit on a kitchen countertop, was introduced.

Soon after, microwave ovens became more popular than even the dishwasher due to decreasing sizes and costs. In , only 4 percent of U. Today, approximately 90 percent of households in the United States have a microwave oven, according to the Bureau of Labor Statistics.

Microwave ovens use radio waves set at a specific frequency — 2, megahertz with a power ranging from to 1, watts, according to the World Health Organization WHO. Food that sits in a microwave oven is bombarded on all sides by the microwaves. Water molecules within the food absorb the microwaves, and the resulting vibrations generate heat and cook the food. Microwaves pass through plastic, glass and ceramic but not metals, which is why it is not recommended to use metal containers or utensils in a microwave oven, according to SciTech.

A magnetron generates the microwaves. According to EngineerGuy , a magnetron is two permanent magnets on either side of a vacuum tube. Microwave radiation is created by the flow of electrons building up magnetic and electric fields, according to Tech-Faq. The microwaves are directed to the oven chamber in order to heat and cook the food. Since their initial development, microwave ovens have gotten a bad rap due to their use of microwave radiation. According to the World Health Organization WHO , microwave ovens are safe when they are used properly and maintained in good condition.

While massive amounts of microwave radiation can be harmful, ovens are designed to keep the radiation within the oven and present only when the oven is switched on and the door is shut. The first commercially available microwave oven also appeared in It was made by Raytheon, it was called Radarange had 1.

In time price fell. In the s, Litton Company developed a new configuration of the microwave: the short, wide shape that is now common, with a magnetron feed that could survive a no-load condition when there is nothing in the oven to absorb microwaves which made microwave oven safer.

This helped rapid growth of the market for home microwave ovens. Prices fell rapidly in the s and microwave ovens became a standard part of households. Facts and History of Microwave A microwave oven, microwave, is a kitchen appliance that is used for heating food. Microwave History Microwave oven was invented by accident.