1. An arc-fault detecting circuit-breaker system operable with a protected electrical circuit, the arc-fault detecting circuit-breaker system comprising:
a normally closed line circuit breaker connected in series by an electrical line with the protected electrical circuit whose current flow is to be interrupted upon the occurrence of an arc fault;
a detector of a rate of change with time of the current flow in at least one of the protected electrical circuit and the electrical line;
an activating element alternating current voltage source having an activating element alternating current output at an activating element alternating current output frequency; and
a circuit-breaker activating element operable responsive to the detector, wherein the circuit-breaker activating element is electrically connected between the electrical line and the activating element alternating current output, and wherein the circuit-breaker activating element is a normally open switch that closes to establish a connection between the electrical line and the alternating current output in the event that the detector detects the rate of change with time of the current flow in excess of a permitted maximum rate-of-change value.
2. The circuit breaker system of claim 1, wherein the protected electrical circuit is a direct current device.
3. The circuit breaker system of claim 1, wherein the protected electrical circuit is an alternating current device having a protected-circuit frequency of no greater than about 200 Hertz.
4. The circuit breaker system of claim 1, wherein the protected electrical circuit is an alternating current device having a protected-circuit frequency, and wherein the activating element alternating current output frequency is at least twice that of the protected-circuit frequency.
5. The circuit-breaker system of claim 1, wherein the line circuit breaker is a resettable circuit breaker.
6. The circuit-breaker system of claim 1, wherein the detector comprises a transformer.
7. The circuit-breaker system of claim 1, wherein the activating element is a silicon-controlled rectifier having a gate of the silicon-controlled rectifier in electrical communication with a detector output signal of the detector.
8. The circuit breaker system of claim 1, wherein the activating element alternating current output frequency is in excess of about 200 Hertz.
9. The circuit breaker system of claim 1, wherein the activating element alternating current output frequency is about 400 Hertz.
10. The circuit breaker system of claim 1, wherein the activating element alternating current voltage source is a single phase voltage source.
11. The circuit breaker system of claim 1, wherein the activating element alternating current voltage source is a two phase voltage source.
12. The circuit breaker system of claim 1, wherein the activating element alternating current voltage source is a three phase voltage source.
13. The circuit breaker system of claim 1, further including
an impedance connected between the detector and the circuit breaker activating element.
14. The circuit breaker system of claim 1, further including
a power diode in series between the circuit breaker and the protected electrical circuit.
15. The circuit breaker system of claim 1, wherein there are two circuit-breaker activating elements, and wherein the circuit breaker system further includes
an alternating gate circuit that alternatingly delivers an output of the detector to the two circuit breaker activating elements.
16. The circuit breaker system of claim 1, wherein the circuit-breaker activating element comprises two silicon-controlled rectifiers, and wherein the circuit breaker system further includes
an alternating gate circuit that alternatingly connects an output of the detector to the gates of the two silicon-controlled rectifiers.
17. An arc-fault detecting circuit-breaker system operable with a direct current protected electrical circuit having a protected-circuit input that receives a direct current electrical signal, the arc-fault detecting circuit-breaker system comprising:
a normally closed line circuit breaker having an electrical input and an electrical output;
an electrical line connecting the electrical output of the normally closed line circuit breaker to the protected-element input;
a detector of a rate of change with time of a current flow in the electrical line;
an activating element alternating current voltage source having an activating element alternating current output at an activating element alternating current output frequency; and
a circuit-breaker activating element operable responsive to the detector, wherein the circuit-breaker activating element is electrically connected between the electrical line and the alternating current output, and wherein the circuit breaker activating element is a normally open switch that closes to establish a connection between the electrical line and the alternating current output in the event that the detector detects the rate of change with time of the current flow in excess of a permitted maximum rate-of-change value.
18. An arc-fault detecting circuit-breaker system operable with a protected electrical circuit having a protected circuit input that receives an alternating current electrical signal at a protected circuit frequency, the arc-fault detecting circuit-breaker system comprising:
a normally closed line circuit breaker having an electrical input and an electrical output;
an electrical line connecting the electrical output of the normally closed line circuit breaker to the protected-element input;
a detector of a rate of change with time of a current flow in the electrical line;
an activating element alternating current voltage source having an activating element alternating current output at an activating element alternating current output frequency at least twice that of the protected-circuit frequency; and
a circuit-breaker activating element operable responsive to the detector, wherein the circuit-breaker activating element is electrically connected between the electrical line and the alternating current output, and wherein the circuit breaker activating element is a normally open switch that closes to establish a connection between the electrical line and the alternating current output in the event that the detector detects the rate of change with time of the current flow in excess of a permitted maximum rate-of-change value.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A recording and reproducing apparatus comprising:
a receiving portion that receives broadcast data;
an extracting portion that extracts video data, audio data, and time information from the broadcast data;
a counting portion that generates system time information from the time information;
a clock generating portion that generates a clock signal in accordance with which the counting portion is operated;
a decoding portion that decodes, the video data and the audio data that are extracted by the extracting portion;
a recording portion that records the broadcast data; and
a control portion that operates to record, a control variable based on which a frequency of the clock signal generated by the clock generating portion is controlled when the decoding portion decodes the video data and the audio data, and to control the clock generating portion by using the control variable.
2. A recording and reproducing apparatus comprising:
a tuner that receives a digital broadcast signal;
an extracting portion that extracts video data, audio data, and time information from the digital broadcast signal;
a counter that generates system time information from the time information;
a clock generating portion that generates a clock signal in accordance with which the counter is operated;
a decoder that decodes the video data and the audio data that are extracted by the extracting portion;
a recording medium that records the digital broadcast signal;
a control portion that operates to record, a control variable based on which a frequency of the clock signal generated by the clock generating portion is controlled when the decoder decodes the video data and the audio data, and to control the clock generating portion by using the control variable.
3. A receiving apparatus comprising:
a tuner that receives a digital broadcast signal;
an extracting portion that extracts video data, audio data, and time information from the digital broadcast signal;
a counter that generates system time information from the time information;
a clock generating portion that generates a clock signal in accordance with which the counter is operated;
a decoder that decodes the video data and the audio data that are extracted by the extracting portion;
an encoder that encodes the video data and the audio data as decoded by the decoder; and
a control portion that controls the clock generating portion by using a control variable based on which a frequency of the clock signal generated by the clock generating portion is controlled when the decoder decodes the video data and the audio data, so that the system time information generated by the counter synchronizes with the time information extracted upon reception of the digital broadcast signal.