Dr. Gibby needs some help with the fabrication issues he describes in his email below for his ventilator project. Before I put this out publicly, does anyone here know someone who has the talent and time to provide the immediate help he needs? (Schematic to PCB design and GERBER files and Analog inputs? (Question GG about analog inputs - would this be for the pressure sensor on J7? Are you looking for a design to scale the range from a transducer voltage to the arduino voltage, multiplex multiple readings over time with the clock, or simply the mechanical connection?) Mickey Baker, N4MB Palm Beach Gardens, FL *“Tell me, and I will listen. Show me, and I will understand. Involve me, and I will learn.” *Teton Lakota, American Indian Saying. ---------- Forwarded message --------- From: Gordon Gibby <docvacuumtubes@gmail.com> Date: Sat, Mar 28, 2020 at 10:58 AM Subject: Re: Ventilators and other fun projects!! To: Mickey Baker <n4mb@arrl.net> THANKS!! right now we are looking for people who can lay out printed circuit boards and create GERBER FILES from them. We have a few people already working on this. I'm enclosing the draft schematic. Ashar Farhan in india is working on this as are a few others, but the more the merrier. We would ask that people provide additional solder connections for additional ANALOG INPUTS from the Arduino as we expect to NEED THEM. The I2C interface is already brought out as you see in the schematic. Attached and link here: https://qsl.net/nf4rc/2020/os_vent.pdf ham radio operators are the driving force BY FAR in the design of the electronic controller. We could not do it without them. The only reason I understood ANY of this was because of Ashar Farhan's innovative uBitx design which I've been working with to help improve for the past 2-3 years. Thanks! Gordon Gibby On Sat, Mar 28, 2020 at 10:53 AM Mickey Baker <n4mb@arrl.net> wrote:
Dr. Gibby,
Your leadership in this project is typical of your performance and exemplifies the American spirit of using our minds and hands to overcome the greatest challenges presented to us.
I've added the ARRL Officers and Board of Directors to this message thread so that they will understand how amateur radio has provided influence to career professionals who are involved in STEM careers.
I'm proud to know you and to have you involved with ARRL as an Assistant Director. After this passes, I promise my support to get your training and publications ARRL Sanctioned.
Thanks. Let me know if you need my support in this project or anything else for the good of the public or amateur radio.
Mickey Baker, N4MB Palm Beach Gardens, FL *“Tell me, and I will listen. Show me, and I will understand. Involve me, and I will learn.” *Teton Lakota, American Indian Saying.
On Sat, Mar 28, 2020 at 9:46 AM Gordon Gibby <docvacuumtubes@gmail.com> wrote:
Dear friends,
I want you to know that without amateur radio operators, this little ventilator project at the University of Florida would be going.....well....not very far, shall we say. FCC Part 97.1 speaks of a trained group of electronics experts as a reason to have ham radio....and here is a PERFECT example of it. There are almost 100 persons contributing on a groups.io site.
But there is more to life than ventilators, so look further down this email!
If you're interested in the ventilators, here is the UF page where they are publishing specifications and where you can watch a 3 minute video they made, running the ventilator through its paces. https://simulation.health.ufl.edu/technology-development/open-source-ventila... Recognize the controller? That's the "tupperware" Raduino that we built to control the Heathkit SB-100 down at the EOC!!! They don't care of course, but it still has the frequency generation and filtering gear right inside of it --- I just "repurposed" it to running a ventilator to save me soldering time Thursday afternoon. Took my 6 hours to do the code for it Thursday night, with the help of another well-known amateur, Jack Purdum W8TEE who has written several books on programming in C and on Arduinos. (Gainesviille Sun article: https://www.gainesville.com/news/20200325/uf-researchers-design-low-cost-diy... )
This morning I had to try and solder a surface mount pressure transducer that is on part with a grain of rice...and solder 7 wires to it. See attached photo. Those are SINGLE STRANDS from a stranded #24 wire from an ethernet cable.....soldering it was not not not not not easy! Hope it works -- it is to prototype measuring airway pressure for the ventilator design. Already-mounted devices were ordered when we realized our goof...but won't be here for several days. Thankfully SOMETHINGS in the country are still working.
If you're more into getting power supplies working during emergencies or field day, specifically to run LAPTOPS -- then I have another little project going. Through Ashar discovered the XL6009 buck-boost voltage converter. Amazing chip can take any voltage from 5 volts to much higher....and produce a steady output voltage of just about any DC you want, from 5 volts to much higher!!! I ordered 2 little circuits from Amazon. You glue the included heatsink on with a tiny bit of epoxy. The little multi-turn potentiometer sets the OUTPUT voltage -- I set it to 19.5 simulating what a laptop needs. Then I powered it from an adjustable MFJ power supply --- no matter where I turn the MFJ, the output stays at 19.5!! Pretty cool.!!! I am not certain what its current rating it -- I think 2 amps maximum??? so it cannot power charging the batteries and everything else but it might keep a laptop going at least.... will have to investigate further and consider 2 units, dunno. The conversion is done at a HIGH frequency -- 400kHz which may make filtering a LOT easier for us. we will see. See attached photo of my first little unit at work powering an LED through a 10K dropping resistor.
If you are intrigued by this little gem, here is the one I ordered: https://www.amazon.com/gp/product/B07NTXSJHB/ref=ppx_yo_dt_b_asin_title_o05_... The same type tricks we have been learning for filtering would work here.
Hope everyone is having fun -- this is a GREAT TIME to work your way through all the IS courses (FEMA) in your Taskbook, and to also succeed at a bunch other tasks in the taskbook!!
See ya!
Gordon Gibby KX4Z