Rotary dial Guide, Meaning , Facts, Information and Description
The rotary dial is a device mounted on or in a telephone or switchboard that is designed to send interrupted electrical pulses, known as pulse dialing, corresponding to the number dialed. It was invented in 1888 by Almon Strowger.The dial is circular, about four inches (10 cm) in diameter, with 10 finger holes cut through the outer perimeter. The dial is mounted via a shaft extending from inside the phone or mounting and sits approximately 1/4 inch (0.7 cm) above a faceplate. The faceplate is set so that through each finger hole letters and numbers printed on the faceplate may be seen. In the US, traditional dials have letter codes displayed with the numbers under the finger holes in the following pattern: 1, 2 ABC, 3 DEF, 4 GHI, 5 JKL, 6 MNO, 7 PRS, 8 TUV, 9 WXY and 0 Operator. However, such letter codes were not used in all countries (older Australian rotary dial phones had them, but the letter combinations were often printed in the centre plate adjacent to the number). The 1 is normally set at approximately 60 degrees clockwise from the uppermost point of the dial (if one imagines an analogue clock face over the dial, the 1 is located at approximately the 2 o'clock position), and then the numbers progress upward counterclockwise, with the 0 being at about 5 o'clock. A curved device called a finger stop sits above the dial at the 4 o'clock position. To dial a 6, the user puts a finger in the 6 finger hole and rotate the dial clockwise until it reaches the finger stop. The user then pulls out the finger, and a spring in the dial returns it to the resting position. As the dial returns, electrical contacts wired through the mechanism underneath will open and close 6 times, thus sending 6 pulses to the receiving end. A centrifugal governor regulates the speed at which the dial returns under the force of the spring.
You can fake out a phone system into thinking you are dialing a phone number without ever turning a dial or pressing buttons. This method will fool the system into thinking you are using a rotary phone. To do this, first find the little button, switch, or hook that is pushed down when you hang up the phone. To "dial" the digit 1, tap it once. For the digit 2, tap it twice QUICKLY. For the digit 3, use three taps, etc. The digit 0 is ten taps. Nearly all newer phone models now have a tone/pulse switch. When pulse mode is activated, the telephone automatically converts the tone into pulses. This is an easier way to dial pulse, but considered a less fun technique.
Many phone lines no longer recogonize pulse dialing, however, and it often has to be ordered separately from a phone company. The shorter dialing times possible for tone dialing added to the shift away from pulse dialing, which is has been largely abandoned in many places now.
Different pulse systems are used depending on which country you are in. Sweden uses 1 pulse to signal the number zero, and 10 pulses to signal the number nine. New Zealand uses ten pulses minus the number desired; so to dial 7, the hook must be pressed three times. For this reason, the numbers on the dial are shifted in different countries to work with their system because of the difference of the number arrangement on the dial.
Note: Not all phone systems and phones support this method.