Arc detection system
The present invention generally directed to arc detection circuits or systems that help prevent fire damage to solid state (LED) based light sources by providing an arc detection system that can be used to detect acing in LED based light fixtures. Once the arcing is detected, power can be quickly turned off to the lighting system. One arc detection circuit according to the present invention comprises a high pass filter circuit arranged to accept an electrical signal with an arc current component having one or more arcing events and a direct current (DC) component, wherein the high pass filter passes only the arc current component. An arc detection circuit is included that accepts the arc current component and filters out arcing events below a threshold. Wherein the arc detection circuit provides an arcing signal with arcing events above said threshold. A microcontroller is also included that accepts the arcing signal to generate control signals based on the arcing signal. In some embodiment, the control signals can be used to control a power supply.
1. An arc detection circuit for, comprising:
a high pass filter circuit arranged to accept an electrical signal with an arc current component having one or more arcing events and a direct current (DC) component, wherein said high pass filter passes only said arc current component;
an arc detection circuit that accepts said arc current component and filters out arcing events below a threshold, said arc detection circuit providing an arcing signal with arcing events above said threshold; and
a microcontroller that accepts said arcing signal to generate control signals based on said arcing signal.
2. The circuit of claim 1 , further comprising an arc current amplification circuit to amplify said electrical signal before being provided to said high pass filter circuit.
3. The circuit of claim 1 , further comprising an arc bypass initial spike circuit arranged to cause an initial turn on current spike not to be considered an arcing event by said arc detection circuit.
4. The circuit of claim 1 , further comprising a detection signal to microcontroller circuit arranged to accept said arcing signal and modify said arcing signal before being accepted by said microcontroller.
5. The circuit of claim 1 , arranged to detect arcing events in an LED based electrical system.
6. The circuit of claim 1 , arranged to detect an arcing event in a light emitting diode (LED) based electrical sign system.
7. The circuit of claim 1 , wherein said microcontroller control signals are used to control a power supply.
8. An LED based system, comprising:
a plurality of light emitting diodes (LEDs);
a power supply for supplying an electrical signal to said LEDs to cause said LEDs to emit light;
an arc detection circuit arranged to detect arcing events in said system, said arc detection comprising;
a high pass filter arranged to accept an electrical signal with an arc event current component and a direct current (DC) component, wherein said high pass filter passes only said arc event current component;
a first sub-circuit that accepts said arc event current component and filters out arcing events below a threshold, said firs sub-circuit providing an arcing signal with arcing events above said threshold; and
a microcontroller that accepts said arcing signal to generate control signals to control said power supply based on said arcing signal.
9. The system of claim 8 , wherein said arc event current component comprises a plurality of arcing events.
10. The system of claim 8 , wherein said arc detection circuit further comprises a second sub-circuit to amplify said electrical signal before being provided to said high pass filter.
11. The system of claim 8 , wherein said arc detection circuit further comprises a third sub-circuit arranged to cause an initial turn on current spike not to be considered an arcing event by said arc detection circuit.
12. The system of claim 8 , wherein said arc detection circuit further comprises a fourth sub-circuit arranged to accept said arcing signal and modify said arcing signal before being provided to said microcontroller.
13. The system of claim 8 , arranged to detect arcing events between electrical conductors.
14. The system of claim 8 , wherein said microcontroller comprises software to generate said control signals based on the arcing signal.
15. The system of claim 8 , wherein said plurality of LEDs comprises two channels of LED each having a respective arc detection circuit.
16. A method for an electrical circuit to detect arcing events in an electrical system, comprising:
a first step of monitoring the electrical signal driving an electrical system;
a second step of separating arcing events on said electrical signal from the remainder of said drive electrical signal;
a third step of detecting said arcing event;
a fourth step of tuning off said drive electrical signal for a predetermined amount of time;
a fifth step of restarting said drive electrical signal; and
a sixth step of repeating said first through fifth steps a predetermined number of time before completing the final step of turning off said electrical signal until manually reset.