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Ifowuni enesandi esinamandla, eyahlukileyo kunye neefowuni eziqhelekileyo ze-analog/IP

IXESHA: 2022-11-03 I-HITS: 46

Sound powered telephone,different with normalindustrial analog/IP telephones

Isandi amandla tkubaniphone is a communication device that allows users to talk to each other using a TVphone, similar to a traditional phone, but without the need for an external power source. Since at least 1944, the technology has been used for day-to-day and emergency communications on ships to communicate between key locations onboard when power is unavailable. A voice telephone circuit can have two or more stations on the same circuit. The circuit is always active, so the user starts talking instead of dialing another station. Voice phones are usually not connected to telephone exchanges.



The microphone transducer converts the sound pressure from the user's speech into electrical current, which is then converted back to sound by a transducer at the receiver node. The most significant difference between a regular phone and a voice phone is the operation of the microphone. Since the microphones used in most phones are designed to modulate the current supplied, they cannot be used with acoustic energy transducers. Most voice phones use dynamic microphones. A common approach to transducer design is the balanced armature design due to its high efficiency. The number of listeners at the same time is limited because the signal is not amplified.


A sound powered telephone circuit can be as simple as two cell phones connected together with a pair of wires, which is defined as the "talk" part of the circuit. The call circuit can be achieved with a pair of wires 50 kilometers (30 miles) long. More complex circuits include magnetos, selector switches, and bells to allow one user to select and call another, which is defined as the "call" portion of the circuit. The voice communication ("talk") circuit is completely separate from the "call" circuit, allowing communication without external power.


U.S. Navy lookout using early audio telephones in the Pacific, circa 1944

Voice phones are widely used on ships. A typical example on a U.S. Navy ship is the "JL" circuit, which is used by lookouts to report visual contact to the wheelhouse and the Combat Information Center (CIC). In this case, there are five stops on the track (stern lookout, port lookout, starboard lookout, wheelhouse and CIC).


USCoast Guard regulations require this emergency communications capability on most ships today, and specify the location of the phone. Dial-up telephone systems with battery backup will not comply with USCG regulations as they currently exist.


Other uses for voice telephony technology today include high-rise buildings, suspension bridges, ski lifts, and emergency communication systems in temporary locations where reliable communication is required. These types of systems allow two or more parties to be able to talk to each other in areas experiencing power loss or when radio communications are subject to radio frequency signal loss and/or limitations.


Audio phones are widely used in ski lifts. Because there are only two phones (rarely three, with intermediate stations), a voice phone is ideal. They are used to confirm the movement of the elevator with other operators, as well as the abnormal operation of the elevator machinery.

Many different types of devices are trying to replace voice phones on ships. Due to the rugged, reliable, and powerless nature of the device, it is still used on all U.S. warships, merchant ships, and work vessels.


Therefore,normalindustrial analog/IP telephonesis more widely used in oil exploitation,chemical industry,prison,tunnel etc.The industrial telephones have many kinds like explosion-proof/iifowuni ezingenamanzi,iifowuni zasejeleand other vandal resistant public telephones.Ningbo Joiwo is specialized in the production of them and in industrial telecommunication and telephone system solution.You're welcomed to contact with us:

Ningbo Joiwo Explosionproof Science & Technology Co., LTD         

Yongeza: No. 695, Yangming West Road, Yangming Street, Yuyao City, Zhejiang Province, China 315400

Umnxeba: +86-574-58223625 / Iseli: +8613858299692

I-imeyile: sales@joiwo.com

Skype: yyxlong01

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