Resistance-No Resistance wire welder

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dsy5

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Ok I removed the 22M resistor and now it only charges up to 64v and continues to drain fast when turned off.
Have parts on the way to make a couple with boost regulator and ordered some extra caps, so will try with one of them.

That's good! Remove the cap and put in a pushbutton switch, a 500Ω resistor and a 1000UF electrolytic cap at 100V all in series. The pushbutton lead will go to the positive hole of the cap and the neg lead of the electrlytic cap to where the negative was on the original cap. Turn it on and measure across the cap while tapping the pushbutton - you should see the voltage rise on the cap. About 32V to 40V should be sufficient to weld wire.
 

TBinAZ

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Ya know, I've been down the road a bit with all of these NR offerings. What does silver offer other than being a PIA? I'm perfectly very happy with SS and nickel. Trying to figure out what I'm pursuing here.

Got one end together with 30g silver/32g kanthal A-1, then couldn't get the other end to take; can only trim so much off the 2nd end before it's time to start over. Oh, well, tomorrow's another day. :D
 

dsy5

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Ya know, I've been down the road a bit with all of these NR offerings. What does silver offer other than being a PIA? I'm perfectly very happy with SS and nickel. Trying to figure out what I'm pursuing here.

Like the nickel, too. Found a 100 foot spool of 30ga for 30 bucks or so, but don't want to spend the cash right now.
 

TomCatt

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Ya know, I've been down the road a bit with all of these NR offerings. What does silver offer other than being a PIA? I'm perfectly very happy with SS and nickel. Trying to figure out what I'm pursuing here.

Silver has the highest conductance. Nickel has ~1/4 the conductance of siliver and SS has ~ 1/40 the conductance of silver. On the other hand, they're all more conductive than nichrome/Kanthal :D
 

dsy5

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Bap - if you want to try a pot to vary the voltage use these values:

R1 - 100kΩ
R2 - 10kΩ
R4 - 10kΩ

This should give a variable voltage out of around 25V to 50V (this is dependent on the voltage of the camera - I'm assuming 325V for calculations sake). The voltage divider is probably not the most efficient way of doing it, but it is certainly the easiest. Current draw is only about 2.7 mA, so I'm not sure how well the cap will charge - in practice, this may not work out well. Might have to go with smaller resistors and larger wattages. Just scale down the individual resistors accordingly and calculate the power - current = Vout camera / R1 + R2 + R3. Power = I²R of each individual resistor.
 
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TBinAZ

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Thanks with cutting the numbers, but my little cheapo rig here does very well with SS and Nickel. I think I'm done here myself.

I just want to throw out creds to all that have been involved here so far. Deep heart felt thanks. I will think about you all when I zap the leads. :toast:

Silver has the highest conductance. Nickel has ~1/4 the conductance of siliver and SS has ~ 1/40 the conductance of silver. On the other hand, they're all more conductive than nichrome/Kanthal :D
 

TomCatt

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Bap - if you want to try a pot to vary the voltage use these values:

R1 - 100kΩ
R2 - 10kΩ
R4 - 10kΩ

This should give a variable voltage out of around 25V to 50V. The voltage divider is probably not the most efficient way of doing it, but it is certainly the easiest. Current draw is only about 2.7 mA, so I'm not sure how well the cap will charge - in practice, this may not work out well. Might have to go with smaller resistors and larger wattages. Just scale down the individual resistors accordingly and calculate the power - current is the sum of the resistors divided into the camera voltage out.

:blink: :blink:

push-button-microswitch-6x6x7mm-400-piezas-envio-gratis_MLM-O-66198476_7394.jpg


zap-150w.gif



bigstock-Cartoon-OUCH-Vector-201473722-100x100.jpg
 

bapgood

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Bap - if you want to try a pot to vary the voltage use these values:

R1 - 100kΩ
R2 - 10kΩ
R4 - 10kΩ

This should give a variable voltage out of around 25V to 50V (this is dependent on the voltage of the camera - I'm assuming 325V for calculations sake). The voltage divider is probably not the most efficient way of doing it, but it is certainly the easiest. Current draw is only about 2.7 mA, so I'm not sure how well the cap will charge - in practice, this may not work out well. Might have to go with smaller resistors and larger wattages. Just scale down the individual resistors accordingly and calculate the power - current is the sum of the resistors divided into the camera voltage out. Power is the individual resistor times the current squared.

I will try it if I can find some 1 or 2 watt resistors.

I'm just trying to use the cameras to do the same as the LM2577/1000uF 50v cap. I'm ok with going easy on the button, but its nice to build in some security, in case I forget.....or more likely someone - hmmm wonder what this button does :D

Is there a "good" and cheap way to limit the voltage if "in practice, this may not work out well"?

I'm going to order some of the LM2577's for the test/break in station I want to build and compare to my camera welders as well.
 

gsa

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Silver has the highest conductance. Nickel has ~1/4 the conductance of siliver and SS has ~ 1/40 the conductance of silver. On the other hand, they're all more conductive than nichrome/Kanthal :D

Nickel is still more conductive than the rest of the atomizer though, so this shouldn't matter.
 

dsy5

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Is there a "good" and cheap way to limit the voltage if "in practice, this may not work out well"?

I'm going to order some of the LM2577's for the test/break in station I want to build and compare to my camera welders as well.

When I mentioned "may not work out well", I was referring to the charging time and a disclaimer due to the fact I have not tested it myself, yet. The effect of adding resistance to the output could change the voltage produced, but I doubt it. This is about the easiest and cheapest way I can think of, shy of stringing about 10 caps in series and picking the voltage off 1 cap in the bunch (which really isn't all that cheap, nor size effective). I will probably give it a test, but not today.
 
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gdeal

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Ok, all of this is so far outside my wheelhouse, but I am gonna toss this out here anyway. If it doesn't make sense, let me know, I got thick skin....I will go back to lurking.

High Voltage Welding - welding of similar and dissimilar metals such as fine wires of gold, silver, brass and others used in such applications as jewelry

The invention in the link is overkill but the theory may be applicable.

EXAMPLE I

______________________________________
Work piece 6 14 carat gold wire
Pre arc 30 volts
Welding arc 5000 μf
Electrode spacing 0.005-0.080 inch
Type joint ....
______________________________________
 

dsy5

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Ok, bap, one more "cheap" alternative: 2 capacitors in series or a 'capacitive divider'. It is basically a takeoff on the 10 caps in series, where 9 of the caps values are combined as 1 cap. The formula for determining the voltage across each cap is:

V of C1 = (C2 / (C1 + C2)) * V applied
V of C2 = (C1/(C1 + C2)) * V applied

So to get about 42 volts across a 1000µF cap, a 150µF cap needs to be in series with it (assuming 325V applied).

Drawback to this method is that it is not adjustable. The smaller cap must be rated to handle close to 275V, where as the larger one could be perhaps 50V.
 
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bapgood

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Ok, bap, one more "cheap" alternative: 2 capacitors in series or a 'capacitive divider'. It is basically a takeoff on the 10 caps in series, where 9 of the caps values are combined as 1 cap. The formula for determining the voltage across each cap is:

V of C1 = (C2 / (C1 + C2)) * V applied
V of C2 = (C1/(C1 + C2)) * V applied

So to get about 42 volts across a 1000µF cap, a 150µF cap needs to be in series with it (assuming 325V applied).

Drawback to this method is that it is not adjustable. The smaller cap must be rated to handle close to 275V, where as the larger one could be perhaps 50V.

That sounds relatively easy...if i understand correctly using a 120uF 330v cap that came on the camera and a 1000uF 50v cap in series, assuming 325v, should = 34.8v
 

dsy5

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That sounds relatively easy...if i understand correctly using a 120uF 330v cap that came on the camera and a 1000uF 50v cap in series, assuming 325v, should = 34.8v

You got it, my friend. Now if you were to adjust those values so that the output was say, 48V and still use the pulsing button method, you could in effect get some variance in the outputted voltage.
 
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