US 8,897,429 B2Granted

Communication circuit employing optocoupler

AssigneesFu Tai Hua Industry (Shenzhen) Co., Ltd., Hon Hai Precision Industry Co., Ltd.

InventorRen-Wen Huang

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Abstract

An communication circuit of a communication device includes an interface unit, a direct current (DC) control circuit, a voice output circuit includes a voice input terminal, and a voice receiving circuit includes a voice output terminal. The interface unit outputs human speech and receives human speech from another communication device. The DC control circuit provides a constant current for the optocoupler circuit. When the outgoing human speech is coupled to the DC control circuit by a first optocoupler and sent to another communication device and incoming human speech is transmitted from the other communication device via the DC control circuit and a second optocoupler, echoes and extraneous noise in the speech is reduced.

Claims19

Dependent claims

A communication circuit of a first communication device, comprising:

an interface unit;
the interface unit outputting a first voice signal to a second communication device and receiving a second voice signal from the second communication device;
a DC control circuit providing a constant current for the communication circuit;
the DC control circuit connecting to a voice output circuit comprising a voice input terminal and a control signal input terminal and a voice receiving circuit comprising a voice output terminal;
and
wherein in DC control circuit comprises a first transistor, a second transistor, a first zener diode and a plurality of resistors;
the first transistor and the second transistor both comprises a first conducting terminal, a second conducting terminal and a control terminal;
the first conducting terminal of the first transistor is electrically connected to the interface, the first conducting terminal of the first transistor is electrically connected to the control terminal of the first transistor via a first resistor, the control terminal of the first transistor is electrically connected to the voice output circuit, the second conducting terminal of the first transistor is electrically connected to the second conducting terminal of the second transistor, the second conducting terminal of the second transistor is electrically connected to the control terminal of the second transistor via a second resistor and a third resistor in series;
a cathode of the first zener diode is electrically connected to the first conducting terminal of the second transistor, an anode of the first zener diode is electrically connected to the interface unit;
wherein the first voice signal into the voice input terminal is coupled to the DC control circuit by a first optocoupler and the interface unit outputs the first voice signal to the second communication device;
and the second voice signal is transmitted from the second communication device via the interface unit and is coupled from the DC control circuit to the voice output terminal by a second optocoupler.

8 more elements

A communication circuit, comprising:

an interface unit;
a direct current (DC) control circuit connecting to the interface unit and providing a constant current to the communication circuit, wherein the DC control circuit comprises a first transistor, a second transistor, a first zener diode and a plurality of resistors;
the first transistor and the second transistor both comprises a first conducting terminal, a second conducting terminal and a control terminal;
the first conducting terminal of the first transistor is electrically connected to the interface, the first conducting terminal of the first transistor is electrically connected to the control terminal of the first transistor via a first resistor, the control terminal of the first transistor is electrically connected to the voice output circuit, the second conducting terminal of the first transistor is electrically connected to the second conducting transistor is electrically connected to the control terminal of the second transistor via a second resistor and a third resistor in series;
a cathode of the first zener diode is electrically connected to the first conducting terminal of the second transistor, an anode of the first zener diode is electrically connected to the interface unit;
a voice output circuit and a voice receiving circuit both electrically connected to the DC current control circuit;
the voice output circuit comprising a voice input terminal receiving an outgoing voice signal and coupling the outgoing human voice signal to the interface unit by a first optocoupler;
the voice receiving circuit receiving an incoming voice signal from the interface unit and coupling the incoming voice signal to a voice output terminal of the voice receiving circuit by a second optocoupler.

5 more elements

A communication circuit, comprising:

an interface unit;
a direct current (DC) control circuit connecting to the interface unit and providing a constant current to the communication circuit, wherein the DC control circuit comprises a first transistor, a second transistor, a first zener diode and a plurality of resistors;
the first transistor and the second transistor both comprises a first conducting terminal, a second conducting terminal and a control terminal;
the first conducting terminal of the first transistor is electrically connected to the interface, the first conducting terminal of the first transistor is electrically connected to the control terminal of the first transistor via a first resistor, the control terminal of the first transistor is electrically connected to the voice output circuit, the second conducting terminal of the first transistor is electrically connected to the second conducting terminal of the second transistor, the second conducting terminal of the second transistor is electrically connected to the control terminal of the second transistor via a second resistor and a third resistor in series;
a cathode of the first zener diode is electrically connected to the first conducting terminal of the second transistor, an anode of the first zener diode is electrically connected to the interface unit;
a voice output circuit and a voice receiving circuit both electrically connected to the DC current control circuit;
the voice output circuit comprising a voice input terminal receiving an outgoing voice signal and coupling the outgoing human voice signal to the interface unit by a first optocoupler;
the voice receiving circuit receiving an incoming voice signal from the interface unit and coupling the incoming voice signal to a voice output terminal of the voice receiving circuit by a second optocoupler;
and
an echo reduction circuit coupled between the voice output circuit and the voice receiving circuit, the echo reduction circuit eliminating an echo between the first voice signal and the second voice signal.

7 more elements

Dependencies are inferred from the claim text.

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Abstract

A communication circuit of a first communication device, comprising:

an interface unit;
the interface unit outputting a first voice signal to a second communication device and receiving a second voice signal from the second communication device;
a DC control circuit providing a constant current for the communication circuit;
the DC control circuit connecting to a voice output circuit comprising a voice input terminal and a control signal input terminal and a voice receiving circuit comprising a voice output terminal;
and
wherein in DC control circuit comprises a first transistor, a second transistor, a first zener diode and a plurality of resistors;
the first transistor and the second transistor both comprises a first conducting terminal, a second conducting terminal and a control terminal;
the first conducting terminal of the first transistor is electrically connected to the interface, the first conducting terminal of the first transistor is electrically connected to the control terminal of the first transistor via a first resistor, the control terminal of the first transistor is electrically connected to the voice output circuit, the second conducting terminal of the first transistor is electrically connected to the second conducting terminal of the second transistor, the second conducting terminal of the second transistor is electrically connected to the control terminal of the second transistor via a second resistor and a third resistor in series;
a cathode of the first zener diode is electrically connected to the first conducting terminal of the second transistor, an anode of the first zener diode is electrically connected to the interface unit;
wherein the first voice signal into the voice input terminal is coupled to the DC control circuit by a first optocoupler and the interface unit outputs the first voice signal to the second communication device;
and the second voice signal is transmitted from the second communication device via the interface unit and is coupled from the DC control circuit to the voice output terminal by a second optocoupler.

8 more elements