Any old working microwave will do

[PJElectricalSW]

Hi again

Random question, do any of you lucky people live or work in East Devon and have an old working microwave laying about you want rid of.

Willing to travel and/or meet somewhere?

Required for spot welder project mk2...

Thanks in advance

 

[Marvo]

C'mon, spill the beans, what you making? I'd guess either a spot welder or a wood burning thingy.

**edit. just saw you mentioned spot welder

 

[PJElectricalSW]

Spot welder mk2, mk1 lasted about 3 welds.

 

[Marvo]

How come MkI was a fail? What happened?

 

[PJElectricalSW]

Don't know, I didn't know the history of the microwave(found in skip at work) so guess the transformer was dead or weak before starting.

Weld 1 was worryingly under powered, weld 2 was uninspiring and weld 3 barely registered. I want sparks and molten metal to spray everywhere then I can work out a way to control it.

Tested afterwards and no resistance on the primary coil to speak of, the thing is so basic it can't be much else other than fooked tranny.

 

[PEG]

Give us your solemn word,that you don't have a DeLorean in the garage...

 

[PJElectricalSW]

Great Scott I've been foiled Marty.

I am attempting to build an electric motorbike with lithium cells, need about 1000 cells and a spot welder that works.

 

[Marvo]

Did you rewing the transformer with a 3 or 4 turn secondary coil? Transformers generally either work fully or don't work at all, you rarely get a case where one deteriorates gradually over time.

You can add control on the primary side using a 1.5kw 2-wire rotary dimmer module so you can adjust the power depending on the material you're welding. R & D Electronics - http://www.dimmers.co.za/no1_red_rotary_dimmer_switched_pot_1500w.htm
I'm sure you'll find something similar from a UK supplier.

 

[dmxtothemax]