Introduction: DIY Arduino Battery Spot Welder

Due to many requests for the PCBs

I do currently have some PCB Sets and prebuilt kits in stock. Take a look here:

https://malectrics.eu


You can also take a look in the comments below this instructable. Some people who ordered boards at PCB manufactures are willing to sell some of them.

Update 05.2017

New V2.2 available with some pcb improvements and the new "AutoPulse" feature. Read More

Update 03.2017
The Spot Welder has a new PCB layout ! Improvements in the V2:

  • only one mosfet driver instead of four
  • changed electrolytic capacitor to film capacitor
  • capacitors closer to the mosfet driver
  • wider pcb traces for high current paths
  • added gate resistors for the mosfets
  • aluminum u-shaped part for the mosfet board (much easier to assemble)
  • general pcb layout improvements
  • pcb is now designed in KiCad (more open source than Eagle)

An Arduino Nano based Spot Welder for battery welding


This Spot Welder can be used to weld 18650 batteries. It needs a 7-12V power source (12V recommended) and uses a 12V car battery as welding current supply. Typically one 45Ah battery delivers enough current to get good welds with 0.15mm nickel strips. For thicker nickel strips maybe you will need bigger battery or two in paralell.

The Welder generates a double pulse, where the first one is 1/8 of the time of the second one. Pulse time of second pulse is adjustable by the potentiometer and displayed on the screen in mS so you can exactly adjust the time. Its adjustable from 1 ... 20 mS.

Watch the Video to get detailed instructions on how to build it.

https://www.youtube.com/watch?v=4qOaeutVR8I

Project Files: (BOM, pcb files, aluminum template, arduino code...)

https://github.com/KaeptnBalu/Arduino_Spot_Welder_V2

Step 1: Making the PCB (V2)

You can find the Eagle / KiCad files for the PCBs on my Github.

Files for Spot Welder V2

Files for the previous Version

Easyest way is to order the boards at an PCB manufacturer. For example at pcbway.com .There you get 10 boards for about 25 €. The necessary gerber files for ordering at pcbway.com can be found in my Github.

You can support me by registering through this link http://www.pcbway.com/setinvite.aspx?inviteid=128...


This way you get a 5$ coupon for your order and i get some percent discount on orders for upcoming projects.

But if you like diy you can also build it on a prototype pcb board with hand wiring. This is how i did the first prototype of the spot welder. In the pictures you see a manufactured board looks much cleaner.

(Update 12.2016)

The trace that connects the two boards in the combined gerber is only a ground connection not needed for the spot welder to work. It is only there to make clear to the pcb manufacturer that this is meant as one board and they dont need to make v-cuts or something else. With this modification it is possible to order at pcbway without problems.

Step 2: Optional: Ordering PCBs at a PCB Manufacturer

So many people asked how to order the pcbs. So here is a little instruction.

Ordering the new V2.2:

For Version 2.2 you need to order the Mosfet and the Arduino board individually because the Mosfet board needs a 2oz copper layer. The Arduino board can be ordered with standard 1oz copper. Dimensions for the 2 boards the same (50mm x 60mm).


Ordering Tutorial (V2 or 2.1): (pcbway.com)

Just go to http://www.pcbway.com/orderonline.aspx . (This is the "PCB Instant Quote" Tab on their Website)Type in Board Dimension (100mmx60mm) and quantity (cheapest is 10). Rest of the options don't need to be changed. You can of course change the colour of the Solder Mask (board colour) or the Silkscreen (text on the boards) to what you like. This does not affect the price. You can see how it shoud look like in the picture.

Then click quote now, choose your favorite shipping option and click "add to basket".

Now you are asked to add the gerber file. Use the spot_welder_v2_gerber.zip or spot_welder_v2.1_gerber.zip from my Github.

(ONLY FOR THE OLD VERSION: You can also order each board on its own with the Arduino_Board_Gerber.zip and the Mosfet_Board_Gerber.zip from my github.)

After clicking "submit order now" the guys at pcbway check if everything is ok with the gerber file. This can take only a few hours but can also take some days, depending on how busy they are.

In the Spot_Welder_V2_Gerber.zip Gerber file the "Mosfet" pcb and the "Arduino" pcb are on one
PCB. So ordering 10 pieces means you get 10 full sets. You have to cut the boards in half at the middle line when you receive them.

Step 3: Populating the Arduino PCB (V2.1)

Most parts used for this spot welder are throug hole components. Only some 1206 SMD parts are used. So its very easy to solder. If you buy the parts i recommend ordering some more of the smd parts because these little things like to disappear on the floor if your not carefull.

Bill of Material (BOM)

Reichelt.de Shopping Cart

In the new V2 version i used 1206 SMD parts for the resistors and the led because there was not enough space for through hole parts.

To solder this SMD parts i figured it is the easiest way to put some solder on all of the pads. Then hold the SMD part in its position with a tweezer and solder one side. Now the part stays in place and you can solder the other side. Now heat both sides alternating and the part will automatically be pulled in its correct position by the solder.

Take care of the SMD leds polarity (see the picture). If it is put in the wrong way arround it wont work.

Populating the rest of the through hole parts is very straight forward. Start with the small flat parts and work your way up to the bigger ones. You can see this in the pictures.

Step 4: Populating the Mosfet PCB (V2.1)

The new mosfet pcb can use a aluminum part instead of the u-bend 16mm2 wire. This makes it much easier to build because you dont need a high power soldering iron and tons of solder. You can of course still use a u-shaped wire instead of the alumium part.

The template for the alumium parts is on my Github. Alumium Parts Template

First screw the u-shaped alumium part to the pcb with m2x8 or m2x10 screws and m2 nuts. Make sure the screw heads are on the pcb side. This is necessary if your srews are a bit to long (m2x10). If you put them in the other way arround they may touch the mosfets later and cause a short circuit. Alternatively solder a 16mm2 wire bend to an u-shape to the pcb.

Now you need to install the mosfets and the straight alumium part. In order to do this bend the mosfets leg in a 90 degree angle with some pliers. Use m3x10 screws and m3 nuts to srew the mosfets with the aluminum part to the pcb. After this solder the mosfets legs to the pcb. Put plenty of solder on the pcb traces that run from the mosfets to the u-shaped aluminum part to make these traces more rigid.

Since you already installed pin headers to the arduino pcb, it is now easy to install the pin headers to the mosfet pcb. Just put the female headers for the mosfet pcb on the ones on the arduino pcb. Lay the Arduino pcb on the table, put the mosfet pcb on top of it and solder the pin headers.

Step 5: Adding Protection Diodes (optional)

Diodes used:

Schottky: VS-100BGQ015 Mouser.com Part: 844-100BGQ015
TVS: 5KP13A-E3/54 Mouser.com Part: 625-5KP13A-E3

Why add diodes ?

The diodes can be used to make the spot welder more reliable when using very high welding currents or long welding cables. They reduce the peak voltage which appears because of the inductance of the welding wires. This is necessary because high voltage spikes could damage or kill your mosfets. A very detailed explanation whats going on can be found here

Adding the diodes:

You can either build some nice wires with cable lugs for the diodes to make it look pretty or solder them directly to the spot welder. The function will be the same. Just make sure to solder on the schottky only with a high power soldering iron so the diode does not become to hot while soldering. The cable for the diodes should be 10mm² ( 7 or 8 awg). For the tvs diode you can also use thinner cable if it is just a very short piece.

Short conclusion of whats going on:

I did some measurements with my 20$ oscilloscope, which is not very accurate, but you can see the effect of the diodes.

The first measurement was done with the normal spot welder with no extra diodes installed.

As you see at the end of the first pulse there is a voltage spike, which reaches up to about 34V. This is no problem as the mosfets are rated for 55V maximum. But if you use longer welding cables or a very strong car battery that can deliver very high current this voltage could probably exceed the 55V. This could then damage or destroy the mosfets.

To get rid of the voltage spikes you can install diodes to the spot welder. You need a TVS and a Schottky diode.

I first did a measurement with only the shottky installed. This lead to a strange oscillating behavior, which can even effect the arduino so the programm crashes. You can see this in the picture with the oscillating voltage.

Last i did a measurement with both diodes (TVS and Schottky) installed. Now the voltage spike at the end of the pulse only reaches about 20V. Even with higher currents or longer welding cables the voltage can not go much hgher because the diodes will prevent this.

Step 6: The Foot Switch

To control the welder you need a foot switch, because both hands are used to hold the welding tips in place.

For the first welder I built it with a simple wood box and a little switch. But meanwhile i bought a dedicated foot switch from china.They are available for example at aliexpress.com for arround 3-4 $.

You can use any switch that is NO (normally open) as a foot switch. It does not carry any current.

Step 7: Using the Spot Welder

Now that your finished builing the spot welder here is how to use it.

Basic infos:

  • recommended welding battery: car battery 12V 40Ah 440A
  • Arduino board power: 12V 2A power supply / 3s Lipo/Liion battery

  • Welding cable: 16mm², each about 50cm long

  • recommended welding material: 0.15mm nickel strip

Safety Instructions:

Only use the spot welder if you have some basic understanding of electricity. We are dealing with very high currents here which can be dangerous.You can not kill yourself by high voltage (its only 12V) but you can for example burn your fingers on the welding tips.

The spot welder is capable of up to 650A welding current for safe operation. Do not use a car battery that can deliver more Amps. For example a 40Ah 440A Car battery works fine to weld 0.15mm Nickel strips to batteries.

If you want to use higher currents or longer welding cables you can do this at your own risk. Absolute maximum rating is about 1000A welding current. In that case or if the device is used very much I recommend upgrading the spot welder with some protection diodes, like the ones described in the diode step.

Do not connect it wrong way around to the car battery. The U-shaped aluminum part which is screwed to the welder goes to the batteries minus (black) pole.

On the first use set the welding time to 1 or 2ms and see how it welds. Then increase the time until you get good welds. If time is set to high, e.g. 20ms for very thin nickel your nickel material will “explode”

Optional: For maximum safety measure the voltage on the two welding tips before every use, to make sure it is around 0V. If it shows 12V (your car batteries voltage) something is shorted out or you got a defective mosfet.

Quick Start:

  • Connect the welding cables and the spot welder according to the connection sketch.
  • Optional: connect the diodes according to the diagram
  • Connect your foot switch to the spot welder
  • Set the welding time with the potentiometer (Display shows 1-20 in milli seconds)
  • Now you can start welding

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Step 8: Adding the "AutoPulse" Feature to Your Existing Spot Welder

In the new V2.2 PCBs the “AutoPulse” feature is integrated, but you
can also upgrade your “old” Spot Welder with the new feature pretty easy.

You only need a few parts: (SMD 1206 or wired parts, depending on what you prefer)

  • 1x 470 Ohm resistor
  • 1x 620 Ohm resistor
  • 1x 20 kOhm resistor
  • 1x Z-Diode (4,3V 0,5w)
  • a piece of thin wire (optional with a connector)

Connect them according to the schematic. (Probe is the mosfets middle Pin) Then upload the new V2.2 Arduino Code to your Arduino Nano.


While the AutoPulse feature is activated you can not use the normal foot switch to activate a pulse. So it is recommended to make the cable that connects to Pin D3 of the arduino removable with a connector. If you do this you need to install the 20k resistor from Pin D3 to GND to make sure the Arduino reads a solid GND signal if the connector is removed.

Alternatively you could flash the Arduino with V2.1 of the Spot Welder software again to disable the AutoPulse feature. Using this method there is no need for the 20k resisor or to make the cable removable with a connector.

Instructions Video: (20k resitor from Pin D3 to GND is missing in the Video, sorry)

Arduino Spot Welder AutoPulse Feature

Step 9: Populating the PCBs and Adding Wires (old Version)

All the parts used for this sopt welder are throug hole components. So its very easy to solder. Start with the small parts and work your way up to the bigger ones.

Welding tips are made of 10 square mm thick solid copper wire. The cables are 16 square mm flexible copper wire. Do not make the welding cables to long (max. 50-60cm each). very long cables can cause high inductive voltage spikes which could damage the spot welder.


(update 08.2016)

- In the new Version you have to connect JP1 on the Arduino Board with JP1 on the Mosfet Board and JP2 on the Arduino Board with JP2 on the Mosfet Board. Use pin headers and sockets. These jumpers connect the ground of the two boards. You can see how it is done in the new pictures with the green pcb pretty good.

(update 12.2016)

- added a new picture series of populating the pcb, which should make it more easy to understand.

Step 10: Frequently Asked Questions - FAQ

What car battery can i use for the Spot welder ?

Recommended is a 12V 40Ah 440A car battery but everything that can deliver 400A to 600A should be fine. I do not recommend to use a so called “deep cycle” battery.They look like a car battery but these are not made to deliver very high currents for a short time. They are meant to deliver little current like 20A to 50A for some hours. They are maybe capable of delivering the high welding current, but could be damaged after some welds.

What nickel strip can i weld ?

You should use 0.1mm or 0.15mm nickel strips.

I have not tested 0.3mm nickel strips. Some people report it works, other say it does not work.

What foot switch can i use ?

You can use any switch that is NO (normally open). The foot switch does not carry any current, so even very tiny switches will work. (Example foot switch)

How long should the welding cables be ?

Make the cables as short as possible. I recommend 16mm2 (5awg) 0.5m for each cable. If you make the cables longer the welding pulse will become weaker unless you use thicker cable.

What power supply do i need for the Arduino board ?

12V 2A or 1A power supply works good. Alternatively a 3s Lipo / Liion battery also works perfectly.

Can i use the car battery to power the arduino board ?

No, you need a seperate power supply or battery.

The voltage drop of the car battery is not the problem. That should be compensated by the capacitors next to the mosfet driver. But at the end of the pulse there is a voltage spike that reaches about the voltage rating of the mosfets. So arround 50V for the IRF1405 mosfets. It is only few micro seconds short but could damage the components on the Arduino board.

Can i get more than the 20mS welding time ?

Yes you can change the welding time in the first line of the Arduino Code by just entering the maximum value you want. (but not higher than 99mS). To learn how top update the Arduino code watch the Youtube Video

Is it possible to use a PC power supply instead of the car battery ?

No, you need a car battery. A pc power supply can not give you enough Amps to weld. You need about 400A. Typicall power supplys can deliver maximum 50A. Also power supplys usually dont like to be shorted, which is what the welder does.

My computer does not find the Arduino when I plug it in with USB !
If your System does not automatically install the necessary driver you need to install it manually. Check out this page: https://arduino-info.wikispaces.com/Nano-USB-Driv...

Comments

author
UNSEPARABLE+TECHSCIENTIFICS made it!(author)2017-07-18

OK!

: D

author
AaronX2621 made it!(author)2017-07-11

Ok I figured out my main issue with V2.2 not pulsing. The BOM has the mosfet driver part number as MCP 14E10-E/P. That's what I had originally purchased which didn't function properly. The name field for this part has MCP1407-E/P. I purchased some MCP1407-E/P drivers and they do function now properly. I do think I killed one or more mosfets even with a the extra protection and one of the 15 ohm resistors nuked itself.

author
KaeptnBalu made it!(author)2017-07-12

Dang it, the part number was wrong in all the BOMs. Sorry for that. I updated the BOMs so it is correct now.

author
AaronX2621 made it!(author)2017-07-12

Thanks for fixing that drove me a bit nuts until I found the error. BTW I did do a BOM on mouser for this should anyone want it.

http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=54cbf7c8a2

It might be cheaper to get the mosfets from an overseas seller on a place like eBay. They’re $18+ through mouser for 8 but I picked up 10 on ebay for $7 shipped. I’m currently waiting on those to come in to test them

Some of the resistors on the BOM are qty 10 because of the price break for 10+, if you need 3 it’s cheaper to get 10

author
CamaronC1 made it!(author)2017-07-04

it works good for 0.15mm tabs but when I try to solder a 0.25mm tab with two psu batteries in parallel every time I fried the mosfets!

author
Rikv13 made it!(author)2017-06-29

Can you eleborate on why the battery can't supply the arduino as well? Is it because when the weld is made, its shorted and therefor cant supply the arduino in that time?

author
KaeptnBalu made it!(author)2017-06-30

The voltage drop of the car battery is not the problem. That should be compensated by the capacitors next to the mosfet driver.

But at the end of the pulse there is a voltage spike that reaches about the voltage rating of the mosfets. So arround 50V for the IRF1405 mosfets. It is only few micro seconds short but could damage the components on the Arduino board.

If you are using the 2 protection diodes the voltage spike is even shorter. So it may work then to power the Arduino Board from the car battery without blowing something up. Have not tested it.

author
AaronX2621 made it!(author)2017-06-12

I have a question! The silkscreen for the 2.2 version has 20k resistors for R1, R13 and R14. The 2.2 version BOM only has 2 resistors of this value needed.

Is one going to not be populated, is the silkscreen value off on one, or is the BOM incorrect for v 2.2?

author
KaeptnBalu made it!(author)2017-06-13

Resistor R13 does not need to be populated. It was meant as a pull down
resistor, but after looking close to the schematic i realised R14 + R15
already do the pull down to GND.

In the latest PCB files on Github i removed R13. So in the next batch of PCBs there will be no R13. I have not received the new PCBs yet, so pictures are not updated.

author
AaronX2621 made it!(author)2017-06-23

Well I have it all built without R13 populated. The device notices when both probes are placed as the LED flashed but I get no actual welding pulse out of it. Where would you start troubleshooting?

author
KaeptnBalu made it!(author)2017-06-24

Remove the AutoPulse Jumper and then put the Test Code on the Arduino.

https://github.com/KaeptnBalu/Arduino_Spot_Welder_...

Then you can measure all voltages with a normal multimeter. More detailed instruction is on Github:

https://github.com/KaeptnBalu/Arduino_Spot_Welder_...

author
AaronX2621 made it!(author)2017-06-27

Still at a loss on this. I do notice I'm getting battery voltage at the welding tips when it's not pulsing (in normal 2.2 programmed mode, not test mode) which the youtube video says should be 0V. I hope the 2.2 pcb file didn't have a problem. I've ordered parts to make a few more of these to test just to see if the first one I assembled was a dud but it's not my first rodeo with SMD soldering. I usually do things smaller than 1206 though :)

author
AaronX2621 made it!(author)2017-06-24

Flashed the nano into test mode. jump the foot switch header with auto pulse off.

Power supply in is 12.89V (it's a 12V wall plug). Nano D5 and pin 2 of the mosfet driver is 5V. LED is 2V but on. Mosfet gates on all 8 of them are 4V

author
mrcsft made it!(author)2017-06-16

I know that a common PC power supply can't deliver the needed Amps but, have you thought about the possibility to use an high current transformer instead of the car battery? I don't think it would be difficult to find one in an old microwave or a UPS and eventually modify the secondary circuit as needed. What do you think about this possibility?

author
Southerner made it!(author)2017-06-06

I tried to place an order at your web site:

https://malectrics.eu

but when the paypal link is taken it just drops back to the cart page and never goes to paypal or places the order.

author
KaeptnBalu made it!(author)2017-06-07

Hi, i updated the website. The Paypal problem should be fixed now. Thanks for the info.

author
wattstar made it!(author)2017-06-02

I still have bits and pieces left from the first version. Includes pretty much everything to make 2 of the V1 design except for the Arduino and cables. I will include 6 sets of V1 boards!

I believe quite a few of the parts are the same in new version. All parts are quality components from reichelt.de $80 all up including postage. Shipping to Australia only.

IMG_4864.JPG
author
testdriver65 made it!(author)2017-05-26

Hi everyone, hi Balu!
After a rather long period of time, I am ready to share with all my experience on the project of the welder case.
Here you can find all files to 3d print your own case:
https://www.thingiverse.com/thing:2346476

I hope that my case will be useful to owners of both old and new versions of the device. The lower space is designed for the use of
copper / aluminum contacts up to 3-4 mm thick. Also there you can find special TVS protection strut.

In my arduino welder i use AUIRF1324 mosfets and protective bus (pair of 1,5KE18CA DO- 201 TVS).

box for welder.jpgArduino welder.jpgstrut.jpg
author
nbiscombe made it!(author)2017-02-26

I cant find the list for all the required parts :( help

author
Switch26 made it!(author)2017-04-26

i hope i am doing this right,can you see the attached file?

BOM_Arduino_Spot_Welder_V2.xlsx
author
tomjasz made it!(author)2017-04-09

now please someone more creative than i replicate a two probe pen. $50 is to much... ideas?

IMG_1217.JPGIMG_1218.JPG
author
Switch26 made it!(author)2017-04-26

shouldn't be hard to make one out of a pice of wood,just drill out two holes just big enough for the probes to fit tightly and perhaps coat the wood with epoxy,i will try it my self and report back with results

author
Switch26 made it!(author)2017-04-26

the only issue would be the wire shouldn't be too thin

12 awg wire should work just fine

author
ve3vxy made it!(author)2017-04-25

Here it is the V2 Spot-welder, My first attempt at the new version and it works great the first time. I used a 150 CCA U1 Battery and Set the welder to 17ms as you can see the welds turned out great, nickle strip I used is 0.15mm. The welding wires are a 8 AWG cut to 50cm with solder-iron tips as welding probes. One more note: I copied your aluminum parts template and the holes did not match the PC board, you may want to fix that. (Just to let you know that I built the original version and it took 4 boards of assembly too get 1 working unit.) Awesome new version keep up the great work Marc.

DSCF1450.JPGDSCF1452.JPGDSCF1453.JPG
author
MichaelS1253 made it!(author)2017-04-21

Can you use a super capacitor bank to power this?

author
dustlessimage made it!(author)2017-04-19

V2.1 version of the maximum current? Can be used to repair welding gold necklace?

author
giurti made it!(author)2017-04-07

Hello,

I have ended to assemble my first welder circuit, and now I'm ready to try it first time.

But I'm worried by risk of short circuit or component damage.

If one mosfet is damaged, can it get to short circuit perpetual state?

Can you suggest me a fuse to add to welder cable?

100A Car fuse can be good?

How much ampere need for welder?

author
KaeptnBalu made it!(author)2017-04-07

Hi,

The welder needs about 400A to function properly. But a normal fuse will not work in this application. If you use for example a battery that can deliver 440A, the welding current for the set pulse time will be close to 440A. So in case of a defective mosfet for example the current will still be 440A but for a longer time.

author
giurti made it!(author)2017-04-10

Your reply increases my worry.

There is not anyone that uses any protection to prevent shorts?

It should be a 'must' for yourself's safety.

author
JeffS331 made it!(author)2017-04-17

I was looking at some fuse time curves and it seems possible to add a fuse around 50 to 100 amps because the current is very high for the first .010 seconds.

Fuse curve.jpg
author
JanS9 made it!(author)2017-04-05

Need PCB V2 in Germany. Has anyone some left over?

author
KaeptnBalu made it!(author)2017-04-07

Just finished my new website. You can get pcbs there if you like.

https://malectrics.eu

author
tomjasz made it!(author)2017-04-09

nice! Fast and very reasonable shipping too. Very very well done! Thank you. Now, a welding pen somone?

author
testdriver65 made it!(author)2017-03-29

Hello everyone!
I made 3D models of the old version of the welder in FUSION 360.
Next step - is to design an optimal box for welder.

http://a360.co/2oxuqKM

WELDER.jpg
author
pistacik made it!(author)2017-03-26

Few comments regarding V2 :
- do we really need 8 gate resistors for the mosfets? Woldn't 1 be enough?
- space under Arduino can be used for TTH parts, too.
-
people with good soldering skills can upgrade V1 with gate resistors,
too. Gate resistor can be soldered between DIP socket and board. For
other pins, piece of wire can be used.

Kudos for V2! It came out before I managed to finish original version!

author
KaeptnBalu made it!(author)2017-03-26

Since the new version only has one driver for all mosfets, each of the mosfets should have its own gate resistor. On the V1 each mosfet had its own driver output and therefore gate resistor were not as critical as on the new v2.

author
HarleyDK made it!(author)2017-03-28

Is there a special reason to use a mosfet driver instead of using mosfets with logic-level gate?

author
KaeptnBalu made it!(author)2017-03-26

The cable for the diodes should be 10mm² ( 7 or 8 awg). For the tvs
diode you can also use thinner cable if it is just a very short piece.

author
tomjasz made it!(author)2017-03-26

I'm sorry, the diode cable is the schottky, should be 7-8AWG?

author

BTW, I have 8 boards in Russia, Kazan. 5 USD/board

author

Hello! I've made welder V1, but it doesnt' work. Mosfets are constantly open, so when i put wires to the battery- I got continuous current and melted wires, even with button not pressed.

Aduino wokrs fine, D5 doest from 0 to 5v and back to 0 when I press the button, LED blinks, display shows ms, MCP drivers seems to be fine- but ...

What should I check?

Thank you in advance.

author
SiddharthS6 made it!(author)2017-03-20

How do I calculate the gate current? Also if someone could tell me the exact current requirements for spot welding to happen.

author
SiddharthS6 made it!(author)2017-03-20

Also, why are the gate resistors needed?

author
SiddharthS6 made it!(author)2017-03-08

Hi!

I wanted to make similar project, but I can't find IRF3704 mosfets anywhere. If anyone could suggest me some alternatives or give me links for IRF3704, it would be absolutely great!

author
KaeptnBalu made it!(author)2017-03-08

Use IRF1405

https://www.reichelt.de/Transistors-IRC-IRF-/IRF-1...

IRF3704 can not carry enough current.

author
SiddharthS6 made it!(author)2017-03-20

10 IRF 3710 won't do the job?

author
matze_rafnex made it!(author)2017-03-08

hi, i build the spot welder and now a make an add-on.

the problem is to work with two hands to hold battery and wire.

there are two RC_Servos MG996 .

Two springs at the upper back of the servos for the right thrust pressure of each servo for itself.I just connected the foot switch to the reed relay of the addon board.
So you can leave the spotwelder platine as it is.

Next, a plexiglass shield with LEDs is attached to protect the eyes, to tilt with switch and a runstop switch. safety first

see the video on youtube

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author
KaeptnBalu made it!(author)2017-03-09

Matze, that is an awesome construction you made there. Love it.

author
Bargenator made it!(author)2016-12-04

Hello everyone, my foray into electronics begins here, I'm an oldie but a goody, in my opinion, I love to tinker, a very fussy builder of RC planes, helis and Hexacopter, race go-karts in the 125tag class for seniors so I have plenty to play with.

I have just ordered 10 spot welder PCB's from PCBWay with both PCB's on the one board, and had a look at the Gerber files as a matter of interest and it shows a trace that runs between the two designs, when the PCB gets cut in half this trace will be cut. I'll assume that this is a manufacturing link between the 2 designs, is this correct, see image for my minor concern.

Some of these boards will be available at cost + shipping if anyone is interested when they arrive.

Cheers

Graham

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mingthemad made it!(author)2017-03-07

Do you have any board sets left for the spot welder? Please let me know how much? Thanks in advance!

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