Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
181 words
A remotely actuable switch (10 for use in testing a remote circuit normally carrying both alternating and direct current, characterized in: at least one solid state bilateral switch (12; 12ai 12a'; 12b; 38, 40) having a first and a second terminal (14, 16) connected in series with said remote circuit and a gate (18) for rendering the switch conductive between said terminals in response to a first predetermined current level; a solid state avalanche device (20; 20a, 20a'; 20b; 50) for each bilateral switch (12) connected between the gate (18) and the second terminal (14) of the bilateral switch (12), said avalanche (20) device being responsive to a first predetermined control voltage ro render said solid state switch (12) conductive, said solid state switch (12) being nonconductive below said control voltage; whereby said switch (10) is normally transparent to and conductive for both alternating and direct currents normally encountered in said circuit at said remote locations, but may be selectively rendered conductive or nonconductive for test purposes by the application of a control voltage above or below said first predetermined voltage.
Claim 2
Dependent Claim
181 words
A remotely actuable switch (10 for use in testing a remote circuit normally carrying both alternating and direct current, characterized in: at least one solid state bilateral switch (12; 12ai 12a'; 12b; 38, 40) having a first and a second terminal (14, 16) connected in series with said remote circuit and a gate (18) for rendering the switch conductive between said terminals in response to a first predetermined current level; a solid state avalanche device (20; 20a, 20a'; 20b; 50) for each bilateral switch (12) connected between the gate (18) and the second terminal (14) of the bilateral switch (12), said avalanche (20) device being responsive to a first predetermined control voltage ro render said solid state switch (12) conductive, said solid state switch (12) being nonconductive below said control voltage; whereby said switch (10) is normally transparent to and conductive for both alternating and direct currents normally encountered in said circuit at said remote locations, but may be selectively rendered conductive or nonconductive for test purposes by the application of a control voltage above or below said first predetermined voltage.
Claim 3
Dependent Claim
19 words
The remotely actuable switch of claim 1, characterized in that said solid state bilateral switch is a triac (12).
Claim 4
Dependent Claim
20 words
The remotely actuable switch of claims 1 or 2, characterized in that said avalanche device is a diac (20) .
Claim 5
Dependent Claim
40 words
The remotely actuable switch of any one of claims 1 - 3, characterized in a means connected in series with said avalanche device (20) for limiting the amount of current flow to the gate (18) of said bilateral switch (12).
Claim 6
Dependent Claim
27 words
The remotely actuable switch of any one of claims 1, 2 and/or 4, characterized in that said avalanche device includes two zener diodes connected back to back.
Claim 7
Dependent Claim
39 words
The remotely actuable switch of any one of claims 1 to 5, characterized in a means for suppressing voltage transients beyond a second predetermined level connected across the first and second terminals (14, 16) of the bilateral switch (12).
Claim 8
Dependent Claim
38 words
The remotely actuable switch of claim 6, characterized in that said suppressing means includes a resistor (26) and capacitor (29) connected in series across the first and second terminals (14, 16) of said solid state bilateral switch (12).
Claim 9
Dependent Claim
89 words
The remotely actuable switch of any one of claims 1 to 7, characterized in its use as a maintenance termination unit (MTU) connected within a remote telephone subscriber circuit, such switch (10) further including: a termination circuit means (32) connected across said remote circuit on the subscriber side of said switches (10) to identify said MTU to a telephone central office. .The remotely actuable switch of claim 8, characterized in that said termination circuit includes a resistance means (31) and at least one diode means (35) connected in series.
Claim 10
Dependent Claim
41 words
The remotely actuable switch of any one of claims 1 to 7, characterized in: a circuit means for supplying said first predetermined current level for actuating said bilateral switch (10) in response to a control signal from a central telephone office.
Claim 11
Dependent Claim
37 words
The remotely actuable switch of claim 10, characterized in that said circuit means includes at least one frequency tone detector (102, 134, 148, 150, 174) which is actuated by a tone generated at the central telephone office.
Claim 12
Dependent Claim
38 words
The remotely actuable switch of claim 10, characterized in that said circuit means includes a voltage and polarity detector means (101) which is actuated by a polarity encoding imposed on a control signal from the central telephone office.
Claim 13
Dependent Claim
25 words
The remotely actuable switch of any one of claims 10 to 12, characterized in that said circuit means includes at least one latching circuit (156).
Claim 14
Dependent Claim
34 words
The remotely actuable switch of claim 10, characterized in that said circuit means includes a resistance-capacitance time constant circuit (110, 112) connected between each remote circuit and ground responsive to a DC control voltage.
Claim 15
Dependent Claim
29 words
The remotely actuable switch of any one of claims 10 to 14, characterized in that said circuit means in- eludes a pilot switch means for each bilateral switch (10).
Claim 16
Dependent Claim
22 words
The remotely actuable switch of claim 15, characterized in that said pilot switch means includes a field effect transistor (FET) (123, 123').
Claim 17
Dependent Claim
37 words
The remotely actuable switch of claim 16, characterized in that said pilot switch includes at least one resistance-capacitance time constant circuit (110', 112') within a bridge for normally energizing said FET (123, 123') and rendering it conductive.
Claim 18
Dependent Claim
33 words
The remotely actuable switch of claim 14, characterized in that said circuit means includes an off-hook detector means (154) for releasing said latching means (156) in response to a permanent condition being removed.