|
|
|
|
|
|
| conference telephone
technique summary |
|
一、Task source
Shenyang SanYuan corporation developed
with huge market-research and test of feasibility,and compiling
the native and international market,the success of this
project stops the monopoly of foreign company, fill up the
vacancy in China.
二、 technology explain： the main technology and resolution
in the design of conference telephone
with the development of electrical
technology and the application of computer in communication,the
technology and service of telephone terminal is greatly
improved, supply the customer with convenience, and are
welcome
1、 hand-free conference telephone
The old hand free phone, send the
sound with loud speaker,but the user still need to speak
into the handle. Because it is very practical,then comes
the hand-free conference phone.
it is easier to use than normal
ones,make more speakers possible,so it is welcome. But in
order to improve the quality of the sound of multi-speaker,many
problems need to be resolved,if not, it influences not only
the quality of sound, and even the net work.
2、key technology
2.1 avoid of feedback of sound
the sound of speaker,can also be
received by the microphone of the phone itself. So sometimes,
there will be self-oscillation,named tweet. Usually, it is
very strong and can influence the whole net-work, and is
not allowed.
The way of feedback,have there kinds sound、electricity
、mechanical.
sound feedback includes：（1）the
sound from speaker,through the air in the room,directly
transfer to microphone,named“nonstop sound” in acoustics；（2）the
sound from speaker,reach the microphone by the reflection
on the wall, ground and ceiling and the things in the room,named
mix sound in acoustics（3）the sound of speaker from phone
crust,reach microphone by nonnormal way.
electricity feedback mainly in phone
circuit,the sound received by microphone,after amplified,is
sent to the line. In order to avoid it, the method of killing
side sound,under the condition , out-line impedance is of
a certain value. In the practical condition,it is always
changing,and can not be managed by the designer. It can
only be removed with special technology.
mechanical feedback comes because
of the vibration of the phone cruse. If microphone can absorb
not only sound but also vibration,they can also mix.
2.2 loudness、limit user and DC resistance
some customer hope the conference phone
can at least as loud as radio,but because of the difference
of electricity feedback,the former is given by the telephone
company's line,and the latter is of battery or stable electricity,so
when the intensity of electricity feedback,it means all
the other factors are managed,it can also not always as
loud as radio .Of course,it is not totally impossible to
improve it.
As we know, with the electricity feedback
of 18mA,telephone's DC feed-in power is only around 72mW. It
can only support the normal work and can not afford the
loud speaker. So, the conference phone can not work well
with 18mA.
2.3 circle-lose
In the native market, the need
of conference phone is more and more,so the need of higher
circle-lose index is based on the application of it. Because
when used, the signal reflected happens not only on the
electricity interface ,but also where the sound and mechanical
feedback happen.
Becuase of the need to provide DC
to hte hand-free part and the DC shoule be got from line,the
way that getting is also very daintily in the design
of phone circuit.
3、 solution of key technique
3.1 the avoid or restrain of sound feedback
There is three way to resolve this problem:acoustics、machine、circuit.
（1） the way of acoustics and machine
The restrain of nonstop sound from
loudhailer to microphone only can be resolved by logical
layout of loudhailer and microphone. General principle is
that the loudhailer and the microphone should be placed
as long as good and even better when the not in the same
plane.Lounhailer with good frequency sound can lighten reverberation.To
the microphone inner the phone shell,the way can be adopt
is that insulate the microphone with all the sound track
inner the phone shell.
Machine feedback is caused by the shell
vibrancy which is caused by the vibrancy of loudhailer.The
solution is lighten the shell vibrancy.This can be got by
thicken the material and add muscle. Also the telephone
transmitter should be placed on the shell by quakeproof
material.
（2）the way of circuit
Telephone has function that transform
between 2 line and 4 line. The signal received by telephone
transmitter ,one part is send to the line,and the other
part is send back to the transmitter,named as side-sound.To
lighten the curcuit feedback,avoiding the side-sound is
the basic.
三、 Our company's conference telephone adopt advanced digital
control technique and acoustics technique.We resolve many
problem like telephone circle-sound by combine acoustics、eletricity
and machine technique.Three inner deliver sound system and
unaided sound box achieve the best sound effects.It supply
high quality communication for all the conference and widely
adapt to top grade meeting room、top grade office and top
grade parlor.All its index tally with nation standard and
has nation patent.
四、 At present,the conference telephone in China market maily
America、Italy and Korea product.This is the compare of these
products.
| Performance\factory |
"Future-Star" conference
telephone |
America conference
telephone |
Italy conference telephone |
Korea conference
telephone |
Control
technique
|
Digital
control and sound control technique |
Digital
control |
Digital
control |
Digital
control |
| Scope of pick up sound |
360° |
360° |
360° |
360° |
| Send frequency sound |
good |
good |
good |
good |
| Receving frequency sound |
Peak value 86db(A) |
Peak value 86db(A) |
Peak value 80db(A) |
Peak value 80db(A) |
| standby power |
no |
yes |
yes |
yes |
| circle sound control |
perfert |
perfert |
good |
good |
| sale price |
1300-4300 |
2300-15000 |
2800-10000 |
2500-8000 |
五、 Our product's creativity and advantage
Our company's conference telephone adopt advanced digital
control technique and acoustics technique.We resolve many
problem like telephone circle-sound、noise、echo and reverberation
by combine acoustics、eletricity and machine technique. There
is foure breakthrough in the design of our product:
1、Place loudhailer and telephone transmitter independently
2、The loudhailer services as sound box and gets high quality
sound effects.
3、Telephone transmitter is made up of three high sensitive
electret and can services 3600's talk.
4、Realize the transform between loudhailer and telephone
transmitter by adopting digital control technique.
六、With the developement of economy and the melioration of
people's life and worke condition,people start to request
comminication terminal with higher performance、practicability
and low price.Our product fulfill this request.It widely
adapt to various of meeting rooms、offices and parlours and
has a very good future. |
|
| |
