Cordless telephone-to-sound card interface adapter with hybrid transformer and control circuit
First Claim
1. A cordless telephone-to-sound card interface adapter for providing mobility to an end user during voice communications over the Internet, comprising:
- a housing unit;
a hybrid transformer circuit carried in the housing unit;
the hybrid transformer circuit including;
a first hybrid transformer;
a second hybrid transformer coupled to the first hybrid transformer;
an impedance matching circuit coupled to the first and the second hybrid transformers;
the first hybrid transformer including a coil A which is inductively coupled with coils B and C formed along the same core;
the second hybrid transformer including a coil F which is inductively coupled with coils D and E formed along the same core;
a telephone jack coupled to the first and the second hybrid transformers and being configured to connect to a cordless telephone system with a telephone cord;
a speaker plug contact for coupling to a speaker plug which is configured to connect to a speaker jack of a computer sound card;
a microphone plug contact for coupling to a microphone plug which is configured to connect to a microphone jack of the computer sound card;
a speaker jack which is configured to connect with an external speaker;
a microphone jack which is configured to connect with an external microphone;
a first terminal of the coil C and a first terminal of the coil E coupled to the telephone jack;
a second terminal of the coil C coupled to a second terminal of the coil E;
first and second terminals of the coil A for coupling to the speaker plug;
first and second terminals of the coil F for coupling to the microphone plug;
a first terminal of the coil B coupled to a second terminal of the coil D;
a second terminal of the coil B and a first terminal of the coil D coupled to the impedance matching circuit;
a control circuit;
the control circuit being operative to switchably connect the speaker and the microphone plug contacts to the first and the second hybrid transformers, respectively, in response to detecting a telephone off-hook condition; and
the control circuit being operative to switchably connect the speaker and the microphone plug contacts to the speaker and the microphone jacks, respectively, in response to detecting a telephone on-hook condition.
1 Assignment
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Accused Products
Abstract
A cordless telephone-to-sound card interface adapter provides a connection between any standard cordless telephone system and a sound card of a computer for PC-to-PC or PC-to-telephone voice communications over the Internet. The interface adapter includes a hybrid transformer circuit for interfacing a two-wire circuit of the cordless telephone and a four-wire circuit of the computer sound card. Consisting of passive components, this hybrid transformer circuit cancels out the voice echo that would otherwise exist due to mismatched impedances between the two media and/or from leakage of the signal being transmitted and received on the same pair of telephone lines. Preferably, a Universal Serial Bus (USB) interface is provided to supply a bias voltage to the cordless telephone system through the interface adapter. The interface adapter may also include interfaces for connecting with external computer speakers and microphone, and a control circuit for automatically switchably coupling the computer sound card to either the cordless telephone or the external speakers and microphone as appropriate.
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Citations
13 Claims
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1. A cordless telephone-to-sound card interface adapter for providing mobility to an end user during voice communications over the Internet, comprising:
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a housing unit; a hybrid transformer circuit carried in the housing unit; the hybrid transformer circuit including; a first hybrid transformer; a second hybrid transformer coupled to the first hybrid transformer; an impedance matching circuit coupled to the first and the second hybrid transformers; the first hybrid transformer including a coil A which is inductively coupled with coils B and C formed along the same core; the second hybrid transformer including a coil F which is inductively coupled with coils D and E formed along the same core; a telephone jack coupled to the first and the second hybrid transformers and being configured to connect to a cordless telephone system with a telephone cord; a speaker plug contact for coupling to a speaker plug which is configured to connect to a speaker jack of a computer sound card; a microphone plug contact for coupling to a microphone plug which is configured to connect to a microphone jack of the computer sound card; a speaker jack which is configured to connect with an external speaker; a microphone jack which is configured to connect with an external microphone; a first terminal of the coil C and a first terminal of the coil E coupled to the telephone jack; a second terminal of the coil C coupled to a second terminal of the coil E; first and second terminals of the coil A for coupling to the speaker plug; first and second terminals of the coil F for coupling to the microphone plug; a first terminal of the coil B coupled to a second terminal of the coil D; a second terminal of the coil B and a first terminal of the coil D coupled to the impedance matching circuit; a control circuit; the control circuit being operative to switchably connect the speaker and the microphone plug contacts to the first and the second hybrid transformers, respectively, in response to detecting a telephone off-hook condition; and the control circuit being operative to switchably connect the speaker and the microphone plug contacts to the speaker and the microphone jacks, respectively, in response to detecting a telephone on-hook condition. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A hybrid transformer circuit for a cordless telephone-to-sound card interface adapter, comprising:
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a first hybrid transformer having a single coil A which is inductively coupled with two coils B and C formed along the same core; a second hybrid transformer having a single coil F which is inductively coupled with two coils D and E formed along the same core; an impedance matching circuit; a telephone jack coupled to first terminals of the coils C and E and being configured to connect to a cordless telephone system with a telephone cord; a second terminal of the coil C coupled to a second terminal of the coil E; first and second terminals of the coil A for coupling to a speaker plug cable which terminates in a speaker plug configured to connect with a speaker jack of a computer sound card; first and second terminals of the coil F for coupling to a microphone plug cable which terminates in a microphone plug configured to connect with a microphone jack of the computer sound card; a first terminal of the coil B coupled to a second terminal of the coil D; a second terminal of the coil B and a first terminal of the coil D being coupled to the impedance matching circuit; a speaker jack being configured to connect with an external speaker; a microphone jack being configured to connect with an external microphone; a control circuit being operative to switchably connect the speaker and the microphone plug cables to the coils A and F, respectively, in response to detecting a telephone off-hook condition; and the control circuit being operative to switchably connect the speaker and the microphone plug cables to the speaker and the microphone jacks, respectively, in response to detecting a telephone on-hook condition. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification