I recently bought 2 Boards from you and all the recommend parts from Mouser and Newark I am in the process of programming the Atmel 328 Micro controller and a question as I am kinda a newbie to micro controllers.
I have an UNO R3 and I purchased an Elcrow AVR ISP Programing Shield AVR Shield and as I am using this to program the code Do I need to burn the boot-loader to the 328 also or is the boot-loader only for use with UNO devices?
dumb question right, but I do not want to let out any magical smoke that makes Semiconductors work.
Looking forward to your answer and all the mean comments others may make calling me an Idiot as in some of the other forums I have Joined.
no comments
also what is typical typical open circuit output voltage should I expect on the rewound MOT
hello,
I live in the US, and can't figure out how to get the 230v board-mounted transformer for the project, as Conrad doesn't deliver to here. does anyone have any thoughts? thanks.
ok. so I think I found an isolation transformer alternative for those who have/want to use a 220v MOT transformer (like the one that came with my non-working Sunkko 788 H), but who (like me) live in the US and can't get a Gerth transformer from Conrad. I just ordered one of these from http://www.newark.com/:
the only differences between the Myrra and the Gerth that AVD specifies on his parts list are:
power rating - 1VA (Myrra) vs 1.9VA (Gerth) and
current - 111mA (Myrra) vs 200mA (Gerth)
if anyone has any questions, comments, or recommendations, let me know.
Yezok1:
I recently bought 2 Boards from you and all the recommend parts from Mouser and Newark I am in the process of programming the Atmel 328 Micro controller and a question as I am kinda a newbie to micro controllers.
I have an UNO R3 and I purchased an Elcrow AVR ISP Programing Shield AVR Shield and as I am using this to program the code Do I need to burn the boot-loader to the 328 also or is the boot-loader only for use with UNO devices?
dumb question right, but I do not want to let out any magical smoke that makes Semiconductors work.
Looking forward to your answer and all the mean comments others may make calling me an Idiot as in some of the other forums I have Joined.
With an ISP programmer, you can program a blank 328 without bootloader.
But you don’t need an ISP programmer.
I program the 328 chips simply with an Arduino UNO board.
Yezok1:
also what is typical typical open circuit output voltage should I expect on the rewound MOT
About 2.5V at open circuit.
hoospiders:
hello,I live in the US, and can't figure out how to get the 230v board-mounted transformer for the project, as Conrad doesn't deliver to here. does anyone have any thoughts? thanks.
In the US you need a 120V 60Hz transformer.
hoospiders:
ok. so I think I found an isolation transformer alternative for those who have/want to use a 220v MOT transformer (like the one that came with my non-working Sunkko 788 H), but who (like me) live in the US and can't get a Gerth transformer from Conrad. I just ordered one of these from http://www.newark.com/:http://www.newark.com/myrra/44050/transformer-1va-230v-1-x-9v/dp/50P9093
the only differences between the Myrra and the Gerth that AVD specifies on his parts list are:
power rating - 1VA (Myrra) vs 1.9VA (Gerth) and
current - 111mA (Myrra) vs 200mA (Gerth)
if anyone has any questions, comments, or recommendations, let me know.
You can't use the Conrad transformer in the US.
avandalen:
With an ISP programmer, you can program a blank 328 without bootloader.
But you don’t need an ISP programmer.
I program the 328 chips simply with an Arduino UNO board.
I ended up flashing the boot loader to a new atmel 328 using the elcrow shield as i kept getting an error if i tried to flash the whole program, then i swapped the chip on the adruino and programed it normally with the uno everything went tickity boo and the spot welder produces some nice welded tabs, i would say it is as good as the welds i get from my local battery supply rip off artist, who indecently was charging a dollar a strip and .75c a weld if i bought the batteries from him and double that price i I supplied the batteries.
avandalen:
About 2.5V at open circuit.
I am getting about 3.6 volts with the rewound MOT, I estimate somewhere over 400 amps as it over ranges my 400 amp clamp on amp meter with dead shorted secondary, makes some nice sparks an any thing smaller than 20 gauge solid copper seems to get vaporized kinda like a blast from a star trek phaser on the highest settings LOL
The Circuit board also works here. Not trying to prove anyone wrong here but for spot welding 18650 cells you can use these from ebay FRM01 Multifunction Self-lock Relay Cycle Timer Module PLC Delay 12V Useful for sale online | eBay and a second one if you wanted to use dual pulse
Replace the Relay with a SSR like this http://www.ebay.com/itm/Output-24V-380V-25A-SSR-25-DA-Solid-State-Relay-For-PID-Temperature-Controller-/252443939068?hash=item3ac6d4d0fc:g:zZMAAOSw8d9Uyc3V
The microcontroller can be used to set a delay-on ( a set time to start start the weld, Like 2 Seconds) and a delay-OFF( the actual weld time can be set from .1sec to 9999hrs:) )
So personally i 've tested these and they have not failed me. Completed one pack already. I could be wrong in using these but let me know what everyone has to say about these.
Albert,
3 weeks ago I ordered 2 sets of your spot welder parts including the pre-programmed 328 chip. I just finished the assembly and it works perfectly. Thank you very much.
Just one question: What options are switches S2, S3 and S4 for?
Also you need to modify the order cart at Mouser Electronics for the crimp terminal used for connecting a foot switch. Two are needed, but only one is set for the order quantity. It is Mouser part# 538-08-50-0185.
Mike in Florida
hoospiders:
Hello,I am going to try to incorporate your pcb and Arduino into two existing Sunkko spot welders (a 709 A and a 788 H) that have both stopped working. While I wait for the parts to arrive, I thought I would ask a couple of questions.
- Do you think that your pcb/arduino combo would allow for the welding of
.25mm (.01") nickel strips? That’s what I've been working with on my pack,
and I would like to continue to use them, as they make a nice strong matrix
and also (I believe) can carry more current with the same resistance (or the
same current with less resistance) than thinner strips.
I am using 0.25mm x 8mm pure nickel strips on 18650 cells. This spot welder is working perfectly.
I am in the USA, so the pc board is set up with the 115v AVB 2,0/2/9 transformer. We can not get 3awg welding cable in the USA, so I used 4awg welding cable for the secondary winding on the MOT. I have not measured the amperage output on the secondary winding, but voltage is 3.43v. The perfect weld timing setting for my battery tabs is (#3 position)150ms. (#2 position) 100ms the tab snaps off the battery too easy when performing a peel test. (#4 position) 200ms burns a hole through the nickel strip and battery. Everyone's setup will be slightly different depending on the MOT transformer power output and the length of welding cable being used.
Now if someone could answer if S2, S3 and S4 have any function with the ATMEGA328 chip programmed as Albert sent it, I would be very happy?
Thank you and Regards,
Mike in Florida
Now if someone could answer if S2, S3 and S4 have any function with the ATMEGA328 chip programmed as Albert sent it, I would be very happy?
am guessing those are used for setting the weld time when using the TFT display.
anishkgt:
Now if someone could answer if S2, S3 and S4 have any function with the ATMEGA328 chip programmed as Albert sent it, I would be very happy?am guessing those are used for setting the weld time when using the TFT display.
Karma,
Thanks, I will try it and see.
Hi Albert, thank you for sharing your work. I have few more questions: I rewired a MOT but I could fit only two turns, voltage without load is 1.5 V and short amp is 1185 A. If I put a 48 ohm resistor in series I'll get 495 A on short. Are those values to high for battery spot welder? Do I have to change anything in your schematic to accommodate my values? In your video I see two separate boards: power board and control board This two boards are implemented in one single board that you have for sale? You mention about WH 50 resistor I noticed that is missing from parts list (is that intentionally?) When you build your battery pack I guess you used a BMS can you direct me where to get a good quality one for 7s6p my ebike motor is 24V 200-380 W? Thank you very much! I tried my rewired MOT with a relay board and Raspberry Pi 3 for counting the times for double pulse. I used copper electrodes also I used tungsten electrodes. The timer is working perfect but for some reason all I get is the metal (I tried on nickel strips and cutter blades) getting red hot around the electrodes but not welding I tried all sorts of times for pulses, on short pulses, I get some welding but very week, any ideas what I may doing wrong? Zero crossing could be the problem? The relay is capable of 10 ms pulse. Thank you again!
Hi Albert,
I was not aware of this forum! I hope I've done this right...
I have been busy building my own version of your design. I can sometimes make it work, but the zero crossing is unreliable, and when measured with a 'scope gives a tiny signal.
Can you please explain the purpose of the rc filter, and why use 1M as series resistor making the signal so small.
Also, how it relates to your code.
Thanks for the work you put into this, and for making it public.
Update: I believe your code detects the falling edge of the sinewave, and I expect that the RC filter is in fact that to protect the input. I am toying with reducing the resistor to say 10k preset so I can adjust the signal level to about 5V peak. Any thoughts? Thanks!
peribox:
Hi Albert, thank you for sharing your work. I have few more questions: I rewired a MOT but I could fit only two turns, voltage without load is 1.5 V and short amp is 1185 A. If I put a 48 ohm resistor in series I'll get 495 A on short. Are those values to high for battery spot welder? Do I have to change anything in your schematic to accommodate my values? In your video I see two separate boards: power board and control board This two boards are implemented in one single board that you have for sale? You mention about WH 50 resistor I noticed that is missing from parts list (is that intentionally?) When you build your battery pack I guess you used a BMS can you direct me where to get a good quality one for 7s6p my ebike motor is 24V 200-380 W? Thank you very much! I tried my rewired MOT with a relay board and Raspberry Pi 3 for counting the times for double pulse. I used copper electrodes also I used tungsten electrodes. The timer is working perfect but for some reason all I get is the metal (I tried on nickel strips and cutter blades) getting red hot around the electrodes but not welding I tried all sorts of times for pulses, on short pulses, I get some welding but very week, any ideas what I may doing wrong? Zero crossing could be the problem? The relay is capable of 10 ms pulse. Thank you again!
The schematic need not be changed no matter how your MOT is wired. All you need to pay attention is the WH50 resistor. Albert used a 22ohm resistor and it should be enough for all the weld tab sizes. Adjusting the weld time should be it. You said you get 495A at short, that would not be enough to melt the tabs. Use the said resistor and it should work. Try to use Copper rods. You can get some from he website or through Banggood.com.
You can also avoid the resistor all together if you intent use it ONLY for batter tab welding by increasing the turns on the MOT to about 30 turns (that can be only found out by trial and error or by calculation, google would be of help)or so. The idea is more turns (thinner cable obviously) = more volts and less Amps. Less turns (Thicker cable) = Less volts and more amps.
Hope this helps.
Update: I believe your code detects the falling edge of the sinewave, and I expect that the RC filter is in fact that to protect the input. I am toying with reducing the resistor to say 10k preset so I can adjust the signal level to about 5V peak. Any thoughts? Thanks!
You got that right !
The resistor protects the IC from the undesired volts. I suggest you leave it that or use an optocoupler like the H11AA1M and code to detect the zero crossing and send a pulse at 5ms after detecting zero cross.
Hope this helps.