US5952741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
External A/C adapter protecting user against hazardous voltage
Assignee: Cisco Technology Inc
•
Filing: 1998-07-15
•
Granted: 1999-09-14
•
Expires: 2018-07-15
Abstract
Abstract A safe external A/C adapter protecting the user against hazardous, high-voltage D/C output. High voltage is defined as any voltage in excess of 60V D/C. The adapter provides an internal remote ON/OFF circuit that automatically switches the D/C output OFF unless the output plug is seated within a mating socket disposed in an electronic device powered by the adapter. When the output plug is so seated, the hazardous voltage output is inaccessible to the user. In addition, a secondary shutdown circuit is provided that latches off the A/C input in the unlikely event that the remote ON/OFF circuit should fail. The secondary shutdown circuit is largely independent from the primary remote ON/OFF circuit, and can be implemented using control circuitry already present in the adapter. No special mechanical connectors are required. Also, because the D/C output is energized only upon insertion of the D/C output plug into the mating socket, and disabled when the output plug is removed, both the electronic device and the user are protected from electric arcing or sparking.
Inventors
- 👤 Samson K. K. Toy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:22
CPC Classifications
H; H01; H01R; H01R13/00; H01R13/66; H01R13/665; H01R13/6666
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
342 words
A system for providing high-voltage from an external A/C adapter to an electrical appliance, comprising: an external A/C adapter including: an A/C input; power-supply circuitry for converting said A/C input into a D/C output of absolute voltage relative to a local ground of more than 60 Volts; a D/C output cord in the form of an insulated cable terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to said local ground, for delivering said D/C output from said adapter to an electrical appliance; a controlling circuit coupled to said D/C output through a first coupler, said circuit capable of regulating said D/C output by controlling said A/C input; a safety switch linked to said D/C output, said switch capable of turning said D/C output on and off; a Remote ON/OFF (ROF) socket disposed within said output plug; an actuator circuit linked to said ROF socket and said safety switch, said actuator circuit capable of turning said safety switch ON when a triggering voltage of less than 60V relative to said local ground is applied to said ROF socket, and turning said safety switch OFF when a voltage other than said triggering voltage is applied to said ROF socket; and a secondary shutdown circuit, linked to said ROF socket and said D/C output and coupled to said controlling circuit through a second coupler, and capable of latching off said A/C input in the event that said triggering voltage is not applied to said ROF socket but said safety switch is nevertheless ON (for example, if said safety switch is shorted); and an electrical appliance including: a mating socket having a plurality of connectors, each said connector complementary to, and capable of mating with, a respective one of said plurality of connectors of said output plug; and an ROF pin, capable of mating with said ROF socket, and shorting said ROF socket to a source of voltage equal to said triggering voltage when said output plug is seated within said mating socket.
Claim 2
Independent Claim
342 words
A system for providing high-voltage from an external A/C adapter to an electrical appliance, comprising: an external A/C adapter including: an A/C input; power-supply circuitry for converting said A/C input into a D/C output of absolute voltage relative to a local ground of more than 60 Volts; a D/C output cord in the form of an insulated cable terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to said local ground, for delivering said D/C output from said adapter to an electrical appliance; a controlling circuit coupled to said D/C output through a first coupler, said circuit capable of regulating said D/C output by controlling said A/C input; a safety switch linked to said D/C output, said switch capable of turning said D/C output on and off; a Remote ON/OFF (ROF) socket disposed within said output plug; an actuator circuit linked to said ROF socket and said safety switch, said actuator circuit capable of turning said safety switch ON when a triggering voltage of less than 60V relative to said local ground is applied to said ROF socket, and turning said safety switch OFF when a voltage other than said triggering voltage is applied to said ROF socket; and a secondary shutdown circuit, linked to said ROF socket and said D/C output and coupled to said controlling circuit through a second coupler, and capable of latching off said A/C input in the event that said triggering voltage is not applied to said ROF socket but said safety switch is nevertheless ON (for example, if said safety switch is shorted); and an electrical appliance including: a mating socket having a plurality of connectors, each said connector complementary to, and capable of mating with, a respective one of said plurality of connectors of said output plug; and an ROF pin, capable of mating with said ROF socket, and shorting said ROF socket to a source of voltage equal to said triggering voltage when said output plug is seated within said mating socket.
Claim 3
Dependent Claim
76 words
The system of claim 1, wherein said ROF pin is recessed in relation to the other connectors in said mating socket, ensuring that when said output plug is inserted into said mating socket, said ROF pin is the last of said plurality of connectors in said mating socket to mate, and conversely, when said output plug is removed, said ROF pin is the first of said plurality of connectors in said mating socket to become disconnected.
Claim 4
Dependent Claim
27 words
The system of claim 1, wherein said source of voltage equal to said triggering voltage is one of said plurality of connectors of said D/C output cord.
Claim 5
Dependent Claim
19 words
The system of claim 1, wherein said triggering voltage is equal to said local ground of said D/C output.
Claim 6
Dependent Claim
47 words
The system of claim 1, wherein said ROF pin is linked to a mechanical safety switch, said switch controlled by a user and capable of preventing said triggering voltage from being applied to said ROF socket even when said ROF socket is mated with said ROF pin.
Claim 7
Dependent Claim
33 words
The system of claim 1, wherein each of said plurality of connectors of said output plug are female sockets, and each of said plurality of connectors of said mating socket are male pins.
Claim 8
Dependent Claim
11 words
The system of claim 1, wherein said switch is a transistor.
Claim 9
Dependent Claim
13 words
The system of claim 1, wherein said first coupler is an optical isolator.
Claim 10
Dependent Claim
13 words
The system of claim 1, wherein said second coupler is an optical isolator.
Claim 11
Dependent Claim
12 words
The system of claim 1, wherein said first coupler is a transformer.
Claim 12
Dependent Claim
12 words
The system of claim 1, wherein said second coupler is a transformer.
Claim 13
Dependent Claim
266 words
A safe external A/C adapter for delivering high-voltage to an electrical appliance, said adapter comprising: an A/C input; power-supply circuitry for converting said A/C input into a D/C output of absolute voltage relative to a local ground of more than 60 Volts; a D/C output cord in the form of an insulated cable terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to said local ground, for delivering said D/C output from said adapter to an electrical appliance; a controlling circuit coupled to said D/C output through a first coupler, said circuit capable of regulating said D/C output by controlling said A/C input; a safety switch linked to said D/C output, said switch capable of turning said D/C output on and off; a Remote ON/OFF (ROF) socket disposed within said output plug; an actuator circuit linked to said ROF socket and said safety switch, said actuator circuit capable of turning said safety switch ON when a triggering voltage of less than 60V relative to said local ground is applied to said ROF socket, and turning said safety switch OFF when a voltage other than said triggering voltage is applied to said ROF socket; and a secondary shutdown circuit, linked to said ROF socket and said D/C output and coupled to said controlling circuit through a second coupler, and capable of latching off said A/C input in the event that said triggering voltage is not applied to said ROF socket but said safety switch is nevertheless ON (for example, if said safety switch is shorted).
Claim 14
Dependent Claim
266 words
A safe external A/C adapter for delivering high-voltage to an electrical appliance, said adapter comprising: an A/C input; power-supply circuitry for converting said A/C input into a D/C output of absolute voltage relative to a local ground of more than 60 Volts; a D/C output cord in the form of an insulated cable terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to said local ground, for delivering said D/C output from said adapter to an electrical appliance; a controlling circuit coupled to said D/C output through a first coupler, said circuit capable of regulating said D/C output by controlling said A/C input; a safety switch linked to said D/C output, said switch capable of turning said D/C output on and off; a Remote ON/OFF (ROF) socket disposed within said output plug; an actuator circuit linked to said ROF socket and said safety switch, said actuator circuit capable of turning said safety switch ON when a triggering voltage of less than 60V relative to said local ground is applied to said ROF socket, and turning said safety switch OFF when a voltage other than said triggering voltage is applied to said ROF socket; and a secondary shutdown circuit, linked to said ROF socket and said D/C output and coupled to said controlling circuit through a second coupler, and capable of latching off said A/C input in the event that said triggering voltage is not applied to said ROF socket but said safety switch is nevertheless ON (for example, if said safety switch is shorted).
Claim 15
Dependent Claim
19 words
The adapter of claim 12, wherein said triggering voltage is equal to said local ground of said D/C output.
Claim 16
Dependent Claim
17 words
The adapter of claim 12, wherein said plurality of connectors of said output plug are female sockets.
Claim 17
Dependent Claim
11 words
The adapter of claim 12, wherein said switch is a transistor.
Claim 18
Dependent Claim
13 words
The adapter of claim 12, wherein said first coupler is an optical isolator.
Claim 19
Dependent Claim
13 words
The adapter of claim 12, wherein said second coupler is an optical isolator.
Claim 20
Dependent Claim
12 words
The adapter of claim 12, wherein said first coupler is a transformer.
Claim 21
Dependent Claim
12 words
The adapter of claim 12, wherein said second coupler is a transformer.
Claim 22
Dependent Claim
77 words
A mating socket for use with the adapter of claim 1, said mating socket comprising: a plurality of connectors, each said connector complementary to, and capable of mating with, a respective one of said plurality of connectors of said output plug; and an ROF pin, capable of mating with said ROF socket, and shorting said ROF socket to a source of voltage equal to said triggering voltage when said output plug is seated within said mating socket.
Claim 23
Dependent Claim
77 words
The mating socket of claim 20, wherein said ROF pin is recessed in relation to the other connectors in said mating socket, ensuring that when said output plug is inserted into said mating socket, said ROF pin is the last of said plurality of connectors in said mating socket to mate, and conversely, when said output plug is removed, said ROF pin is the first of said plurality of connectors in said mating socket to become disconnected.
Claim 24
Dependent Claim
28 words
The mating socket of claim 20, wherein said source of voltage equal to said triggering voltage is one of said plurality of connectors of said D/C output cord.
Claim 25
Dependent Claim
14 words
The mating socket of claim 20, wherein said plurality of connectors are male pins.
Claim 26
Independent Claim
167 words
A system for providing voltage from an external A/C adapter to an electrical appliance, comprising: an external A/C adapter including: an A/C input; circuitry for converting said A/C input into a D/C output; a D/C output cord terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to a local ground, for delivering said D/C output from said adapter to an electrical appliance; a switch linked to said D/C output, said switch capable of turning said D/C output on and off; and an actuator circuit to said switch and controlling said switch according to a triggering voltage applied to at least one of said plurality of connectors of said output plug when said output plug is mated with said electrical appliance; and an electrical appliance including; a mating socket having a plurality of connectors each said connector complementary to, and capable of mating with, a respective one of said plurality of connectors of said output plug.
Claim 27
Independent Claim
167 words
A system for providing voltage from an external A/C adapter to an electrical appliance, comprising: an external A/C adapter including: an A/C input; circuitry for converting said A/C input into a D/C output; a D/C output cord terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to a local ground, for delivering said D/C output from said adapter to an electrical appliance; a switch linked to said D/C output, said switch capable of turning said D/C output on and off; and an actuator circuit to said switch and controlling said switch according to a triggering voltage applied to at least one of said plurality of connectors of said output plug when said output plug is mated with said electrical appliance; and an electrical appliance including; a mating socket having a plurality of connectors each said connector complementary to, and capable of mating with, a respective one of said plurality of connectors of said output plug.
Claim 28
Dependent Claim
51 words
The system of claim 24, further comprising: a controlling circuit coupled to said D/C output, said controlling circuit capable of regulating said D/C output by controlling said A/C input, and a secondary shutdown circuit, linked to said output plug and capable of latching off said A/C input if said switch fails.
Claim 29
Dependent Claim
53 words
The adapter of claim 25 wherein said actuator circuit is capable of turning said switch ON when a triggering voltage of less than a predetermined level is applied to said output plug, and turning said switch OFF when a voltage at or higher than said predetermined level is applied to said output plug.
Claim 30
Dependent Claim
126 words
An external A/C adapter for delivering voltage to an electrical appliance, said adapter comprising: A/C input; circuitry for converting said A/C input into a D/C output; a D/C output cord terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to a local ground, for delivering said D/C output from said adapter to an electrical appliance; a switch linked to said D/C output, said switch capable of tuning said D/C output on and off; and an actuator circuit linked to said switch and controlling said switch according to a triggering voltage applied to at least one of said plurality of connectors of said output plug when said output plug is mated with said electrical appliance.
Claim 31
Dependent Claim
126 words
An external A/C adapter for delivering voltage to an electrical appliance, said adapter comprising: A/C input; circuitry for converting said A/C input into a D/C output; a D/C output cord terminated by an output plug having a plurality of connectors, wherein at least one of said plurality of connectors is linked to a local ground, for delivering said D/C output from said adapter to an electrical appliance; a switch linked to said D/C output, said switch capable of tuning said D/C output on and off; and an actuator circuit linked to said switch and controlling said switch according to a triggering voltage applied to at least one of said plurality of connectors of said output plug when said output plug is mated with said electrical appliance.
Claim 32
Dependent Claim
51 words
The adapter of claim 27, further comprising: a controlling circuit coupled to said D/C output, said controlling circuit capable of regulating said D/C output by controlling said A/C input; and a secondary shutdown circuit, linked to said output plug and capable of latching off said A/C input if said switch fails.
Claim 33
Dependent Claim
53 words
The adapter of claim 28 wherein said actuator circuit is capable of turning said switch ON when a triggering voltage of less than a predetermined level is applied to said output plug, and turning said switch OFF when a voltage at or higher than said predetermined level is applied to said output plug.
References Cited (Backward Citations)
US4591732A
Cited
US4704599A
Cited
US4835737A
Cited
US4871924A
Cited
US4995017A
Cited
US4915639A
Cited
US5203004A
Cited
US5293636A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-09-13 | 2003-03-15 | 2003-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-09-13 | 2007-03-15 | 2007-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-09-13 | 2011-03-15 | 2011-09-14 | $7700.00 | Window Closed / Lapsed |