MOV varistor
14D471K metal-oxide varistor · 470 V at 1 mA · clamps surges, absorbs about 70 J · use across mains after the fuse
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: Metal-oxide varistor
Pins
- Lead 1
- Lead 2
Ratings and limits
| V at 1 mA | 470 V |
|---|---|
| Energy | 70 J |
| Use on | 230 V mains |
How to use it
Across the mains after the fuse. Normally it draws nothing; a surge pushes it into conduction and it clamps the spike. Repeated surges wear it out, and a failed MOV shorts and blows the fuse.
Lessons and builds that use it
- 65 W USB-C PD charger from scratch: mains flyback (UC3844, 800 V MOSFET, PQ2625 transformer), TL431 + PC817 feedback, PD controller (build)
- Real device: phone charger, 220 V AC wall to 5 V USB (build)
- Real device: laptop charger, 220 V AC wall to 20 V with PFC (build)