Overvoltage protection with status signalling
The present invention teaches an overvoltage protection device that includes at least one non-linear resistance element and a single cut-off device coupled with the at least one non-linear resistance element to disable the at least one non-linear resistance element when the at least one non-linear resistance element reaches a pre-determined temperature. The single cut-off device may include stranded wire, a first solder having a first melting point connecting the stranded wire to the at least one non-linear resistance element, and a second solder having a second melting point, higher than the first melting point, connecting the stranded wire to the at least one non-linear resistance element. The single cut-off device may further include a shifting part that shifts when the at least one non-linear resistance element heats the first solder to the first melting point. In other particular embodiments, the overvoltage protection device may further include a status indicator configured to be moved by the single cut-off device to indicate one of at least two conditions of the at least one non-linear resistance element. The status indicator may include a lever, and the single cut-off device moves the lever to indicate the one of at least two conditions of the at least one non-linear resistance element.
1. An overvoltage protection device, comprising:
a. at least one non-linear resistance element; and
b. a single cut-off device coupled with the at least one non-linear resistance element to disable the at least one non-linear resistance element when the at least one non-linear resistance element reaches a pre-determined temperature, wherein the single cut-off device comprises
i. a shiftable actuator;
ii. a first solder having a first melting point connecting the actuator to the at least one non-linear resistance element, the actuator movable to a first shift position upon melting of the first solder; and
iii. a second solder having a second melting point, higher than the first melting point, connecting the actuator to the at least one non-linear resistance element, the actuator movable to a second shift position upon melting of the second solder; and
iv. a status indicator operably connected to the actuator to give a visual indication of a first condition of the non-linear resistance element at the first shift position of the actuator and a different visual indication of a second condition of the non-linear resistance element at the second shift position of the actuator.
2. The overvoltage protection device of claim 1 , wherein the at least one non-linear resistance element is a varistor.
3. The overvoltage protection device of claim 1 , wherein the actuator comprises a shifting part that shifts when the at least one non-linear resistance element heats the first solder to the first melting point.
4. The overvoltage protection device of claim 3 , wherein the shifting part shifts to disable the at least one non-linear resistance element when the at least one non-linear resistance element heats the second solder to the second melting point.
5. The overvoltage protection device of claim 1 , wherein the status indicator comprises a lever and the actuator moves the lever to indicate the one of at least two conditions of the at least one non-linear resistance element.
6. The overvoltage protection device of claim 5 , wherein the status indicator further comprises a spring connected to the lever to bias the lever.
7. The overvoltage protection device of claim 1 , wherein the shiftable actuator comprises
a lever;
a conductive connecting element;
a spring connected to the lever to bias the lever against the conductive connecting element;
an adaptor coupled to the conductive connecting element; and
wherein the first solder connects the adaptor to the conductive connecting element, and the second solder connecting the adaptor to the non-linear resistance element.
8. The overvoltage protection device of claim 1 , wherein the shiftable actuator comprises
a lever;
a conductive strip adaptor coupled to the at least one non-linear resistance element;
a spring connected to the lever to bias the lever against the conductive strip; and
wherein the first solder connects the conductive strip to the non-linear resistance element, and the second solder connects the conductive strip adaptor to the at feast one non-linear resistance element.