kenemon 29 Posted December 23, 2011 Share Posted December 23, 2011 I want one. Hitting the thrift stores lookin for ovens. Do you have any more pcbs you might want to sell? Quote Link to post Share on other sites
ohmselectronics 6 Posted December 23, 2011 Share Posted December 23, 2011 Hello Kenemon, not sure where you are but if you are in Dallas, the toaster ovens are $23 at Elliot's (coit/park in plano) i think those have the infrared lamps as opposed to the wire resistors. later. Quote Link to post Share on other sites
lukasoft 0 Posted December 27, 2011 Share Posted December 27, 2011 2.7 usd for LCD screen: (URL removed, "Your post looks too spamy for a new user") This item apparently will not ship to the united states, but the price is outrageously cheap. Does anyone have a cheap source for them that ships to the US? I would love to do this project over spring break. Quote Link to post Share on other sites
jim940 28 Posted December 27, 2011 Share Posted December 27, 2011 Tons of options on Ebay for very cheap LCD's. Jim Quote Link to post Share on other sites
zeke 693 Posted December 27, 2011 Share Posted December 27, 2011 FYI, I found this SSR is much cheaper than the Crydom unit: Only $7.32 each at mouser. Quote Link to post Share on other sites
username 198 Posted December 27, 2011 Author Share Posted December 27, 2011 FYI, I found this SSR is much cheaper than the Crydom unit: Only $7.32 each at mouser. That would be interesting to try a version with a solid state relay. The "alarm lsd" in my schematic would work for driving a SSR. If you look at the schematic, the LSD(low side driver) that is hooked up to the green led has a resistor in series with the load. That resistor can be populated to anything and then the outputs could go to a input SSR. (aka a LED load most commonly) With a SSR, Ideally you would be able to switch more frequently without risk of damaging contacts. You would also be able to switch at a higher rate. With a SSR and some holes drilled into the oven to allow it to cool down faster,ideally you could implement a better algorithm. However, it would all come down to how good your heat sinking is. Since a SSR isn't a perfect conductor in the on state, power is dissipated over it(aka heat). Even more power is dissipated during turn on and off since your rise/fall times are not instant. You would also have to worry about the inrush current hurting the relay. Every cold start turn on would have a decent amount of inrush current. Thus, if your heat sinking isn't adequate or the inrush is too much, there is no solid guarantee that the relay won't fail in the closed state. If it fails in the closed state and you are not aware of it, you would risk damaging your board due to the oven not turning off. Again, if one could ensure the protection of their relay, one could run a more advance pwm based heating algorithm. So, it would be something to look into if anyone is interested. For me, my contact relay is enough and if it fails, it will fail in the open state and is only a 3usd replacement should that happen. All that is good enough for me . I'll try to get the BOM up when I get home from break as well as ship out some pcbs to anyone who is interested. Will probably happen around friday. Quote Link to post Share on other sites
zeke 693 Posted December 30, 2011 Share Posted December 30, 2011 I was just reading Elektor's website and I noticed that they sell a reflow oven. They want US$3495 for it :crazy: Still, when you look at what they've made, it looks really nice. They even have oven profile software to drive it. Maybe we could "borrow" some ideas to improve on ours? Quote Link to post Share on other sites
username 198 Posted January 2, 2012 Author Share Posted January 2, 2012 Possibly, the next step would probably be to incorporate a SSR and a convection oven. Anyhow, another good step is to get a better MCU on there that has more coding space available to allow for more advance control. I redid the PCB to work with the MSP430G2553. =) Hardware SPI should also be able to be implemented with the MAX6675 or the newer cold compensator model. Hoping to ship these out and have a nice new control board kit ready to donate for the next POTM Quote Link to post Share on other sites
bluehash 1,581 Posted January 2, 2012 Share Posted January 2, 2012 Looks good. What software do you use for PCB layout? Quote Link to post Share on other sites
zeke 693 Posted January 2, 2012 Share Posted January 2, 2012 Looks like Altium to me. Quote Link to post Share on other sites
oPossum 1,083 Posted January 3, 2012 Share Posted January 3, 2012 Deja vu all over again Quote Link to post Share on other sites
ohmselectronics 6 Posted January 4, 2012 Share Posted January 4, 2012 I was just reading Elektor's website and I noticed that they sell a reflow oven. They want US$3495 for it :crazy: Still, when you look at what they've made, it looks really nice. They even have oven profile software to drive it. Maybe we could "borrow" some ideas to improve on ours? Hello Zeke, Naah, profesionally made hobby reflow ovens go for as little as ~$250 T-962 = ~$250, T-962 INFRARED IC HEATER REFLOW WAVE OVEN BGA T962 800W 180 Quote Link to post Share on other sites
zeke 693 Posted January 4, 2012 Share Posted January 4, 2012 Oh my! That Chinglish was Horrible! Quote Link to post Share on other sites
ohmselectronics 6 Posted January 4, 2012 Share Posted January 4, 2012 Oh my! That Chinglish was Horrible! Ya think? but i ain't no paying no $3450... that would be kinna worst... Hahahaha so you think i am Chinese? i am starting to wish i was since most of our jobs are moving overseas, i was being sarcastic... sorry i just realized your are not an American... regards Luis-chan Quote Link to post Share on other sites
zeke 693 Posted January 28, 2012 Share Posted January 28, 2012 Nah, I didn't think you were Chinese. I thought whoever wrote that English was Chinese. My fingers are crossed that it wasn't you. Concerning those T962 ovens, they don't have a lot of fans. I read a bunch today about various options and they have been thoroughly slagged in a couple different forums: here and here. Today, I bought this 1500W convection toaster oven for $60. I know I could have gotten something cheaper but this was the cheapest with the circulation fan inside. I'll be making my own PID controller. I'll be using a solid state relay for safety reasons. Quote Link to post Share on other sites
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