Thanks, The scr's, capacitor and transformer will cost the most. You can get them on E-bay at very low prices.The rest of the components will be about +-$80.I'm busy updating the schematic and step by step instructions.
Nice jobs. I plan to build one according to your video on youtube. By the way, what's the specification of the capacitor? (Voltage and capacitor).Thanks Stanley Hsu stanley.hsu1@gmail.com
Yes, you can use mosfets by using the 25Ma signal on connector P3. Mosfets however needs to be turned on and off at a speed that does not exceed di/dt and enough parallel mosfets have to be used to insure that they don't form a bottleneck which will slow down current flow.
Brian, a 24 volt transformer will give you, when put through a rectifier +- 33 to 36 volt DC. The size of your transformer will determine the speed that your capacitor will charge. You can use a smaller transformer. It takes about 4 seconds to charge a 3 farad cap with a 100VA transformer(4 Amp). You might want to look on ebay for 24v toroidal transformers
I bought this SCR for $25 and they emailed me they have more at that price. It looked like a good deal to me. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350221803522&ssPageName=ADME:B:EOIBSA:US:1123
Brian, I have designed this welder around a 3 Farad cap. You can use a 2 Farad but your welds will be shorter than it was designed for. I found this cap on ebay and if the specs are correct, it should be perfect.I'm not saying that this IS the right cap but the only way to know is to buy and try it. If you get it, let me know and I'll show you the correct way to test the Farads (don't try and use formulas and directions from Forums on the internet, they will just lead you in a wrong direction) http://cgi.ebay.com/New-Legacy-3-0-Farad-20V-Digital-Power-Capacitor-w-LED_W0QQitemZ120463970335QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item1c0c36501f&_trksid=p3286.c0.m14
Hi Fritz, This is amazing. I would love to tackle this project. I'm not very skilled in electronics but I try to help myself. I did build a simple welder with CGC caps nothing fancy, I found the schematic on the net. Can you provide a parts list and also did you ever decided to source the PCBs? Does this involve any type of programming? I hope not because I've no clue of but willing to learn. I will appreciate any help that you can give.
Damian and Brian, Don't start to build this project yet. I'm busy solving a couple of problems with the charging system and then I'm going to work on making this a dual pulse solid state welder. Everything cost money and I'm working on a budget here so please be patient. I will make all the information available when I'm done
Do you have any kind of a Bill of Materials or price list for the components?
ReplyDeleteGreat looking project!
Thanks, The scr's, capacitor and transformer will cost the most. You can get them on E-bay at very low prices.The rest of the components will be about +-$80.I'm busy updating the schematic and step by step instructions.
ReplyDeleteI'm done with the code for the Microprocessor and are currently running it through some vigorous testing.
ReplyDeleteNice jobs. I plan to build one according to your video on youtube. By the way, what's the specification of the capacitor? (Voltage and capacitor).Thanks Stanley Hsu
ReplyDeletestanley.hsu1@gmail.com
Is possible to remplace the scr to Mospowers? Thanks
ReplyDeleteYes, you can use mosfets by using the 25Ma signal on connector P3. Mosfets however needs to be turned on and off at a speed that does not exceed di/dt and enough parallel mosfets have to be used to insure that they don't form a bottleneck which will slow down current flow.
ReplyDeleteHave you considered selling this as a kit?
ReplyDeleteBrian, I might have a couple of PCB's professially made and sell them. Kits will be too expensive and way too much work.
ReplyDeleteFritz, Thank you for your reply. Let me know if you are going to sell the PCB's. Where do you get a 20AMP 36VDC power suply?
ReplyDeleteBrian, a 24 volt transformer will give you, when put through a rectifier +- 33 to 36 volt DC. The size of your transformer will determine the speed that your capacitor will charge. You can use a smaller transformer. It takes about 4 seconds to charge a 3 farad cap with a 100VA transformer(4 Amp). You might want to look on ebay for 24v toroidal transformers
ReplyDeleteI found an Amveco toroidal for $25 on Ebay that fits the bill. What are the specs on the bridge rectifier?
ReplyDeleteThanks,
Brian Steg
50 Amp Brian. I got 2 coming from Hong Kong.
ReplyDeletehttp://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260470714910&ssPageName=STRK:MEWNX:IT
What do you think of this for the 24VAC 100VA power source?
ReplyDeletehttp://www.powersupplydepot.com/productview.asp?product=17636+PS
Sorry,
ReplyDeleteI sent the wrong link;
http://www.powersupplydepot.com/productview.asp?product=16854+PS
I don't know Brian. It looks good to me but you are going to have to buy and try it to be sure
ReplyDeleteI bought this SCR for $25 and they emailed me they have more at that price. It looked like a good deal to me. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=350221803522&ssPageName=ADME:B:EOIBSA:US:1123
ReplyDeleteIts hard to find the Volfenhag 3 Farad capacitor. What about the 2 Farad (one or two?) for $30 at;
ReplyDeletewww.millionbuy.com/vofzx22.html
Brian, I have designed this welder around a 3 Farad cap. You can use a 2 Farad but your welds will be shorter than it was designed for.
ReplyDeleteI found this cap on ebay and if the specs are correct, it should be perfect.I'm not saying that this IS the right cap but the only way to know is to buy and try it. If you get it, let me know and I'll show you the correct way to test the Farads (don't try and use formulas and directions from Forums on the internet, they will just lead you in a wrong direction)
http://cgi.ebay.com/New-Legacy-3-0-Farad-20V-Digital-Power-Capacitor-w-LED_W0QQitemZ120463970335QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item1c0c36501f&_trksid=p3286.c0.m14
Hi Fritz, This is amazing. I would love to tackle this project. I'm not very skilled in electronics but I try to help myself. I did build a simple welder with CGC caps nothing fancy, I found the schematic on the net. Can you provide a parts list and also did you ever decided to source the PCBs? Does this involve any type of programming? I hope not because I've no clue of but willing to learn. I will appreciate any help that you can give.
ReplyDeleteDamian and Brian, Don't start to build this project yet. I'm busy solving a couple of problems with the charging system and then I'm going to work on making this a dual pulse solid state welder. Everything cost money and I'm working on a budget here so please be patient. I will make all the information available when I'm done
ReplyDeleteOk, Thank you for your prompt responds.
ReplyDeleteFritz,
ReplyDeleteWhat is the origin of the red case you have put your components in? Was it a welder to start with? What make & model is the case?
Thanks,
Dave
Dave, it was a Lincoln Plasma cutter. I cant remember the model.
ReplyDelete