A post by Miduoduo314

DIY welder fail diary: a JX-D99 five-MOSFET welder board is a ‘toy’ without enough punch; adding MOSFETs, it blew after a dozen or so welds, a second one still wasn’t enough; finally switched to an AWithZ UF20B (1750A); welding 0.1 nickel strip gives bright, clean welds

The creator ‘teaches you welders’: first a JX-D99 welder board (a toy) + welding pens, hooked to a battery, five MOSFETs underneath; it felt underpowered so he added MOSFETs at the back, and after a dozen or so welds it blew; bought another and it still didn’t feel up to it; then switched to an AWithZ welder, model UF20B, 1750A, 5000W instantaneous (nameplate: 6.0V MAX, 1750A MAX, 10.5kW MAX, 100–240V, Shenzhen Juequi Technology); test-welded two pieces of 0.1-thick nickel strip — welds very good, bright and clean. Comments: ‘so the conclusion is you bought a welder for a few hundred bucks’, ‘you’re teaching us to buy a welder’, ‘talked into buying yet another one’; someone says Xiaoqiang’s can reach 2500+; someone claims a 5-MOSFET board with a 4S 120C battery at gear 75 can weld 0.1 nickel stacked on 0.5 copper (creator: no way).

Outcome

Steps4 steps · click a frame to jump

1. 
   1. JX-D99 welder board + pens, five MOSFETs

   Teaching you welders; this is a welder ‘toy’ (JX-D99 board) and a welding pen; hook up the battery first; five MOSFETs underneath.

   00:00 – 00:09
2. 
   2. Not enough punch, added MOSFETs and it blew, bought another and still no good

   Felt underpowered, so added MOSFETs at the back; the one he added earlier blew after a dozen or so welds; bought another and it still wasn’t up to much.

   00:09 – 00:18
3. 
   3. Switch to the AWithZ UF20B: 1750A / 5000W

   Switched to an AWithZ welder, model UF20B, 1750A, 5000W instantaneous; nameplate 6.0V / 1750A / 10.5kW MAX.

   00:18 – 00:28
4. 
   4. 0.1 nickel strip test weld: bright, clean welds

   Two pieces of 0.1-thick nickel strip; look at the weld result; welding is very good, welds are bright and clean.

   00:28 – 00:47

Bill of materials

Pitfalls

• The DIY welder board blew after a dozen or so welds once MOSFETs were added; a second board was still underpowered 00:11

Li-ion safety

• MOSFETs blowing 00:14

Quotes