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Introducing a New Member

jw0752

I recently met a new friend. He was working on a medical device and was referred to me as someone who could help him find some parts he needed. His name is Von Wolff. As I learned about him and his background in Electronics I felt he would make a good member for the element 14 Forum. I recommended that he join and I was really pleased when he followed through and signed up. Von has for over 30 years been a Design and Verification Engineer in the field of integrated circuit design and function. He has been involved in designing complex ICs for aerospace and commercial industrial applications. He has experience with many of the specialized hardware and software tools used in the design and verification process. He has completed contract projects with over 20 major companies but some of his best stories are from his beginnings working for Walt Disney, designing the ride control systems for Disneyland, Disney World, and the Epcot Center. He also spent a time designing spacecraft monitoring systems for NASA at the Jet Propulsion Lab. Von retired in 2017 and recently he has been working on some bio-electronic projects. I am looking forward to continuing my friendship with Von and I hope my friends on element 14 give him a nice welcome. As we have all experienced, the forum can be a little challenging to figure out and navigate on first contact so any hints and tips will probably be appreciated.

 

John

  • in reply to jw0752

    I know what you mean - I have a couple of cheaper boards/cheaper patch wire kits and on reflection were not my best buys (before anyone asks, they weren't purchased from Farnell). I remember years ago that you could get replacement contacts for the better quality boards - not sure if that is the case now; I think it was the Maplin professional range of breadboards, available in a nice blue colour.

     

    Rod

  • in reply to 14rhb

    Hi Rod,

     

    Von has done an excellent job wiring the prototype up despite the connection difficulties imposed by the density and complexity of the wiring. Functionality has been greatly affected by some less than quality breadboards and patch wires.

     

    John

  • in reply to genebren

    Hi Gene,

    The machine is working as hoped for but I believe the jury is still out on whether it is having the therapeutic results hoped for. In single person tests like this it is impossible to have any kind of control group and Von has struggled to develop a performance baseline that he can use for comparison. We are still very hopeful and Von has continued with a very positive approach to the project.

    John

  • in reply to jw0752

    Hi Von and John,

     

    Very skillful breadboard work there, not sure I could have achieved that level without occasionally pulling out a wire with my clumsy hands image

     

    Rod

  • in reply to jw0752

    Looks like you work is coming along nicely.  That is quite an impressive prototype.  Are you getting the results he was looking for?

     

    Gene

  • in reply to jw0752

    Hi John and ,

     

    That's an impressive prototype! Also congrats on the really nice design methods you're using - The PCBs look easy-to-build and maintain, and such a modular design could also allow people to experiment with changes too perhaps, e.g. different levels.

    Thanks for the update and interesting photo.

  • Since I introduced   to the forum back in July he has been working tirelessly to design and construct a PONS neural modulator. I have been privileged to be his lab assistant in this endeavor. To date Von has built a breadboard prototype of the modulator and has been running field tests on it. The project has been complicated as there are 16 channels each of which have 4 different attenuation paths before contact with neurons. The complexity has made for problems keeping all the jumper wires on the breadboards in place and making proper contact. Here is a picture of the bread boarded prototype.

     

    image

     

    In the last month or so Von has been working to put the unit on circuit boards. Today he brought over the interface board which takes in the 16 channel output and breaks out the 4 different attenuation lines for each channel and provides the 64 pin output to the body interface board. The new board replaces about a third of the above pictured breadboarding. Here is a picture of the new interface/ attenuation board and the body interface board.

     

    image

     

    Along the way I made a small custom power supply for the unit, assembled some MOSFET driver modules that were inspired by and and I have been having a blast assisting Von with this project. Von is off to design the next replacement board and we will be soon totally on circuit boards and hopefully will no longer be bothered by loose wires and intermittent problems.

     

    John

  • in reply to jw0752

    John,

     

    The signals look good.  I really like the way you were able to modularize the driver onto a single adapter.  Very cool!

     

    Gene

  • in reply to michaelkellett

    Hi Michael,

    I love electronics, there are so many elegant ways to get from point A to point B. there are even some inelegant ways as evidenced from some of my own designs. I will mention your idea to Von. We are probably locked into the present path though as the parts have been ordered and time is of the essence to Von. Thank you for the idea. I am always interested in what you have to say.

    John

  • in reply to jw0752

    I've come very late to this discussion - only spotted it today.

     

    This may be a daft suggestion but here goes:

     

    Why not just use a quad op amp as the driver - may not be optimum for cost but an OPA4192 can do 0 - 30V, 20V/us slew rate, 10 mA drive easily, more for non continuous operation.

     

    Can get it in a TSSOP14 package so it's tiny. Resistors in 0402 or 4 in 1206 won't take up much space.

     

    Let me know if the idea is appealing and I'll think of a circuit.

     

    MK