Another SMD lebowski PCB

Electric Motors and Controllers
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Lebowski
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Joined: Jun 28, 2011 1:38 am
Location: beautiful Zurich, Switzerland

Re: Another SMD lebowski PCB

Post by Lebowski » Dec 13, 2017 3:04 pm

Try calculating their cost by weight... :shock:

whereswally606
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Joined: Jun 19, 2011 2:11 pm
Location: Cheshire, UK

Re: Another SMD lebowski PCB

Post by whereswally606 » Dec 27, 2017 3:45 pm

So I had ago at putting a digital pot 10k into a Chinese scr. I desoldered the 500k 2w ohm pot and soldered a 3 wire breakout to go to my breadboard. I then wired up the digital pot to the nano and to the scr. It had a looping code which continuously turned the wiper up to 128 and back down to 0.

However when I went to test it on a router, it didn't appear to work and I'm guessing it's because the pot that came out was for 500k and this digital pot is 10k.

I wanted to double check that I'd uploaded the code so I did something stupid which was plug the nano back into my pc before unplugging the mains. Big spark, dead nano and for a moment thought I'd killed my pc. However luckily was just the RCD tripped to cut the mains power to everything.

So plan c is I have a spare 5 wire stepper motor and so I've just bought a uln2003 driver for it to use it on the nano. I will use the stepper to turn the 500k pot mechanically which will allow me to use my pc to monitor the serial of the nano in real time and not have to use the ropey Nokia LCD for output. I know this is a rube Goldberg approach but I think it's the safest for me right now and I know it will work.

Plan d is to build one of Andy browns through hole smd reflow controller boards. But I hope I can avoid that.

Still not received the new PCBs from pcbway as they are delivering to work and I'm not there till the new year. Hopefully January will be more productive.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
Moped: Emax 110s 2009

whereswally606
100 kW
100 kW
Posts: 1126
Joined: Jun 19, 2011 2:11 pm
Location: Cheshire, UK

Re: Another SMD lebowski PCB

Post by whereswally606 » Jan 11, 2018 10:15 am

received the new wson pcbs yesterday. I have sent off today for a new solder paste stencil from oshstencils which cost about £10 but I think worth it to get the accuracy I need deploying the paste layer.

My friend has a stencil cutting machine but I don't think it has the accuracy of pitch so a tenner is really here nor there at this point.

I had some success with building a nano Arduino and stepper driver to turn the pot on the SCR so I almost have a reflow oven operational. I can see this happening soon now. I only have one pic chip from bas ("lebowski") at the moment and the first prototype is off to him to run on his power board when I build it. Customers ones to follow.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
Moped: Emax 110s 2009

whereswally606
100 kW
100 kW
Posts: 1126
Joined: Jun 19, 2011 2:11 pm
Location: Cheshire, UK

Re: Another SMD lebowski PCB

Post by whereswally606 » Jan 15, 2018 5:57 am

stepper motor scr for reflow oven web2.png
stepper motor scr for reflow oven web2.png (241.35 KiB) Viewed 23 times
Here is the progress on my automation of the dimmer switch for my reflow oven. I worked out how to control the stepper forward and backward one 3/4 turn so that the dimmer is fully on and fully off with no overshoot. Now i can use this code with my old relay code directly, or modify it slightly so that it varies the dimmer relative to the heat differential of the target temp and the actual temp in the halogen oven. Some familiar to the mpcnc project my recognise my repurposing of the pineapple connector which had been superceeded in the mpcnc design.

still to do.

receive new wson stencil from oshstencils for 15 boards with variant wson chip (should be soon)
modify halogen oven with silver foil and reduce angle off fan blades to reduce their power blowing about the little smd pcb parts.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
Moped: Emax 110s 2009

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