Video Phone Terminal Equipment

Video Phone Terminal Equipment

A video telephone is a terminal device that transmits voice in both directions by electrical signals.

The history of the video phone improvements and inventions include: toner microphone, telephone manual switchboard, dial pad, automatic telephone exchange, program-controlled telephone switches, dual tone multi-frequency dialing, voice digital sampling. In recent years, new technologies include ISDN, DSL, analog mobile phones and digital mobile video telephony. The history of the video phone improvements and inventions include: toner microphone, telephone manual switchboard, dial pad, automatic telephone exchange, program-controlled telephone switches, dual tone multi-frequency dialing, voice digital sampling. In recent years, new technologies include ISDN, DSL, analog mobile phones and digital mobile video telephony.

March 10, 1876 Alexander Graham Bell invented the video phone, the video phone has become a necessity. Normally, Alexander Graham Bell is the inventor of the phone. The United States Congress on June 15, 2002, Resolution 269 confirmed that Antonio Meucci (Antonio Meucci) for the inventor of the phone. "AGBell invented the video phone is different.Through the very complex Morse code, the development of the general people are very easy to use the degree of Bell invented the phone is 1: 1 way, but with The development of new materials, the development of the exchange technology, the way of paging changes and the development of Internet telephony, etc., after the development of modern mechanical civilization has become a living necessities of society now let everyone share some video phone common faults and maintenance Method:

One, off-hook silent off-hook silent that is unreasonable, often caused by the DC circuit is not normal, can be off-hook state of the city outside the line voltage.

Second, the call is normal, but can not dial the normal call, can explain the dial-up chip to start the circuit work properly

(1) dial-up chip can not get the normal working current.

(2) The clock oscillation circuit does not operate.

(3) dial keyboard circuit is not normal.

(4)) handle can not send.

(5) handle to send voice is small, if the receiver of the bias voltage of about 2V, mostly for the receiver lead or reverse the lead.

(6) handle can not be heard.

1. no ringing, send the normal analysis of maintenance: video phone to send normal, indicating that the video phone can work properly, the on-hook state outside the phone does not ring, you can determine the fault occurred in the ringing circuit.

2. Ringing sound anomaly analysis overhaul: video phone ringing sound abnormalities. Refers to the outside calls when the ringing sound is small, ringing sound for the single tone, ringing sound harsh distortion and so on.

3. Ringing sound becomes smaller, indicating that the ringing circuit work is basically normal, but a component deterioration or leakage, resulting in ringing circuit voltage abnormalities caused by ringing sound smaller.

4. Ring once the automatic off-hook analysis overhaul: video phone appears this failure, the reason may be ringing input circuit in a component breakdown or poor printed circuit insulation, leakage, ignition, etc., outside the call ringing after the breakdown , So that the ringing input circuit constitutes a DC circuit, the program-controlled switches mistakenly believe that the video phone has been off-hook, and thus stop sending ringing signal caused by automatic off-hook failure.

5. After hanging on the ring after the continuous analysis of overhaul: the video phone calls normal, hang up after the ringing constantly, the fault should occur in the ringing input circuit.

6. When the outside call ringing good and bad when the analysis of overhaul: outside the call when the video phone is sometimes ringing normal, sometimes not ringing, according to maintenance experience, the reasons for this failure is generally ringing circuit components are bad While the hands-free switch (self-locking) causes the possibility of failure.