I'm a graphic designer and not a pro, so I apologize for the wiring diagram, but the best way I understand this stuff is if I can see the wiring. I can read a circuit, half way, but translating the circuit into the wiring is tough for a rookie like me. I am trying to wire up a small DIY arc welder, any help or pointers on the wiring would be appreciated. I had a version working and running, with no resistors and only one 4700 Capacitor, but wanted to try and set it up for multiple caps and configurations for options in the circuit. Also did not have any resistors in the circuit, would like to protect the Caps and the board both. I am not sure if I am close, or way off. I have cobbled it together from various forums and circuits found online, but I think this is "close"? or maybe not. The two power supplies is to keep the LED voltage display from bleeding the charge from the caps...at least that was the idea. Maybe the vets and pros out there see my glaring mistakes... ???? Any help is appreciated and thank you very much for any help in advance.

 

What voltage does the 'Welder Power Supply' put out? You may be able to run the LED display from that.
Why the diode? It is a 1A type and seemingly has far too low a current rating.

 

up to 50 volts is put out on the board, the power supply is anything over 4 volts i believe, 4-34v. The diode was in just for "good measure", to keep backfeed from damaging the board or caps. I had a working version with a 4700uf cap, but changed to try and gain optional settings for the caps, adding as needed. also I had no resistors in the working version. thanks for looking at it, any idea if it is wired up correctly? I can always change out the diodes, but was trying to get at least the circuit wired up. Been a long couple days trying to get this right, had to break down and ask for help, any and all info is greatly appreciated and I thank you.

 

Wiring looks ok.

I had a working version with a 4700uf cap

Did that version include the 1N4002?

 

I built this one and it worked, but didn't have a charge or discharge push button switches, N/O push buttons, and also was 4700uf which sometimes was too much, so I wanted to run three 1000uf in parallel with a DPDT option to engage them one at a time, and was trying to add resistors in. The LED is on separate power because there is another function the LED serves, and I know it is possible to run the LED with the same power but this avoids two different problems and is no inconvenience running two power sources. Yes it included the same diode.

 

i looked at this with fresh eyes this morning, and thought I might need to move the black- connection wire to the #3 Cap's black/- terminal. would this be right?

 

The "good measure" diode was vaporized the first time you fired this spot welder.

The 220Ω 0.5W resistor was likely vaporized the first time you tried to charge up the capacitor bank.

It takes over 3 seconds to charge 3000uF through 220Ω, during which the resistor dissipates a peak power of >11W, so you need to do something about that, maybe change it to a 5W or 10W resistor.

With the 220Ω, the peak current out of the 50V supply is ~230mA. Can the supply stand that?

What is the "momentary Delay switch" wired across the spot welder terminals supposed to do?

 

multi metered the diode, not fried. I have both 5 watt and 10 watt resistors on hand, but I am going from other working models that all started with those higher value resistors and went to the .5 resistor after trial and error. I am not claiming i invented this stuff, or even understand it fully, I am just trying to do a little wiring. lol. the momentary delay switches are in there for the charge and discharge. instead of having to turn the power off, I wanted to be able to charge the caps with the red switch, when depressed it closes the circuit for the caps to charge. the second Mom switch was to discharge the circuit in case the charge was not used to weld, it would be a way to get the charge out of the caps without touching the leads... I spent all day yesterday trying to wire this, stripped it down to base components and wires this morning, trying fresh today.

 

am i fairly close to the wiring? I can always increase the specs on parts was my thinking?

 

With the 220Ω, the peak current out of the 50V supply is ~230mA. Can the supply stand that?

I have a couple 440ohm resistors on hand?

 

With the 220Ω, the peak current out of the 50V supply is ~230mA. Can the supply stand that?

I have a couple 440ohm resistors on hand?

But then it will take more like 10sec to charge 3000uF to 50V.

 

typically it never goes to 50 volt, about 35 volt is sufficient. the problem I had with the original simple circuit with only one 4700uf cap was that I could not charge or discharge, it was either on or off with the power button, and the 4700uf was too much for some wires, creating more heat than needed for thinner wires, so i was hoping to drop in a CHARGE Mom button, and discharge mom button both, as well as switch the caps to the best suited configuration. I also wanted to try and protect the board and caps, so thought that was done with resistors? I really appreciate you taking the time to look at these, I am kinda stuck. I have all parts stripped down and wanted to try and re-wire this again today.

 

just a side note, the amount of time taken to charge this up is not a problem, it isn't meant to be instant, or even quick, if the charge takes 4, 8 or 10 seconds to charge, that isn't a real problem. it is what it is.

 

assuming I can get the specs configured and values correct for the resistors and charging, does the DPDT switch configuration/wiring look correct, and same for the Charge and Discharge switches, do they look wired correctly? thanks very much for all the help, it is appreciated