Telephone System

The telephone is a familiar end instrument in telecommunication switching system. The development of telephone and circuits started around midst 1850. The table 3.1 shows the development of telephone.

Table 3.1. Development of telephone



Early 1854

Charles Bourseul discovered the vibration due to speech waves on the sufficiently flexible disc. Also he found this vibration can made and brake current from a battery.

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DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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