IP Library › Granted Patent US 12688957
Granted Patent B2
US 12688957 · App. 18/486,277 · Granted Jul 21, 2026

Thermally protected metal oxide varistor

Inventors: Hailang Tang (Dongguan, CN); Dongjian Song (Dongguan, CN); Charles Hu (Dongguan, CN)
Assignee: Dongguan Littelfuse Electronics Company Limited
H01C7/12H01C1/14
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Quick Facts
Patent No.
US 12688957
App. No.
18/486,277
Granted
Jul 21, 2026
Kind
B2
Abstract

A metal oxide varistor (MOV) includes an MOV body, a first electrode, a second electrode, and a thermal cut-off insulation shell. The MOV body is a crystalline microstructure with zinc oxide mixed with one or more other metal oxides. The first electrode is adjacent one side of the MOV body and is connected to a first radial lead. The second electrode is adjacent a second side of the MOV body and is connected to a second radial lead having a curved portion. The thermal cut-off insulation shell is adjacent the second electrode and has a protrusion, with the curved portion of the second radial lead being adjacent the protrusion.

Claims (13)

1 . A metal oxide varistor comprising:

a metal oxide varistor body comprising a crystalline microstructure featuring zinc oxide mixed with one or more other metal oxides;

a first electrode disposed adjacent a first side of the metal oxide varistor body, wherein the first electrode is coupled to a first radial lead;

a second electrode disposed adjacent a second side of the metal oxide varistor body, wherein the second electrode is coupled to a second radial lead, wherein the second radial lead comprises a circular portion; and

a thermal cut-off insulation shell disposed adjacent the second electrode, the thermal cut-off insulation shell comprising a cylindrical protrusion, wherein the circular portion fits around the cylindrical protrusion.

2 . The metal oxide varistor of claim 1 , the second radial lead further comprising a vertical portion extending radially outward from the metal oxide varistor body, wherein the vertical portion is connected to the circular portion.

3 . The metal oxide varistor of claim 2 , the second radial lead further comprising an end portion, wherein the end portion is affixed to the second electrode using a soldering paste.

4 . The metal oxide varistor of claim 3 , wherein the end portion moves away from the second electrode once the soldering paste melts.

5 . The metal oxide varistor of claim 1 , wherein the second radial lead is a phosphor copper wire.

6 . The metal oxide varistor of claim 1 , wherein the second radial lead comprises bronze C5191.

7 . The metal oxide varistor of claim 1 , wherein the second radial lead comprises steel.

8 . The metal oxide varistor of claim 1 , wherein the thermal cut-off insulation shell comprises Al2O3.

9 . The metal oxide varistor of claim 1 , wherein the thermal cut-off insulation shell comprises plastic.