From: jl@glen--canyon.com   
      
   On Tue, 2 Dec 2025 16:17:03 +1100, Bill Sloman    
   wrote:   
      
   >On 2/12/2025 5:56 am, john larkin wrote:   
   >> On Tue, 2 Dec 2025 05:07:57 +1100, Bill Sloman    
   >> wrote:   
   >>   
   >>> On 2/12/2025 3:02 am, john larkin wrote:   
   >>>> On Mon, 1 Dec 2025 21:35:40 +1100, Bill Sloman    
   >>>> wrote:   
   >>>>   
   >>>>> On 1/12/2025 2:32 am, john larkin wrote:   
   >>>>>> On Mon, 1 Dec 2025 00:28:19 +1100, Bill Sloman    
   >>>>>> wrote:   
   >>>>>>   
   >>>>>>> On 30/11/2025 4:56 pm, john larkin wrote:   
   >>>>>>>> On Sat, 29 Nov 2025 11:17:12 -0800, Joerg    
   >>>>>>>> wrote:   
   >>>>>>>>   
   >>>>>>>>> On 11/29/25 3:38 AM, Bill Sloman wrote:   
   >>>>>>>>>> On 29/11/2025 8:56 am, Joerg wrote:   
   >>>>>>>>>>> On 11/28/25 1:32 PM, Joe Gwinn wrote:   
   >>>>>>>>>>>> On Fri, 28 Nov 2025 12:52:07 -0800, Joerg    
   >>>>>>>>>>>> wrote:   
   >>>>>>>>>>>>   
   >>>>>>>>>>>>> On 11/28/25 12:45 PM, Joerg wrote:   
   >>>>>>>>>>>   
   >>>>>>>>>>> [...]   
   >>>>>>>>>>>   
   >>>>>>>>>>>>>> To the surprise of my clients it's the contrary. The most   
   >>>>>>>>>>>>>> client-shocking redesign was an auto-align circuit for ganged   
   >>>>>>>>>>>>>> ADC-channels. High speed, high phase accuracy and all that. They   
   >>>>>>>>>>>>>> had an   
   >>>>>>>>>>>>>> elaborate time domain method with a fat DSP, lots of code and   
   very   
   >>>>>>>>>>>>>   
   >>>>>>>>>>>>>       I meant they used a frequency domain method.   
   >>>>>>>>>>>>>   
   >>>>>>>>>>>>>> expensive chips used as programmable delay chips. The NRE alone   
   had   
   >>>>>>>>>>>>>> been   
   >>>>>>>>>>>>>> humongous. It never reliably converged so the system hung a   
   lot. I   
   >>>>>>>>>>>>>> suggested to ditch all that and use time domain. This caused an   
   uproar   
   >>>>>>>>>>>>>> because I had rocked the boat a lot and usually consultants   
   aren't   
   >>>>>>>>>>>>>> supposed to do that. "I don't think this can possibly work",   
   "It won't   
   >>>>>>>>>>>>>> deliver the accuracy", "It won't converge either" and all that.   
   >>>>>>>>>>>>>>   
   >>>>>>>>>>>>>> Yet the boss let me do it. In the end the whole thing dropped   
   from   
   >>>>>>>>>>>>>> three-digit dollars in HW to under 10 bucks. Instead of   
   expensive   
   >>>>>>>>>>>>>> discrete-step time delay chips I used inductors, caps and   
   varicap   
   >>>>>>>>>>>>>> diodes   
   >>>>>>>>>>>>>> for almost infinite granularity. The DSP became unemployed   
   because the   
   >>>>>>>>>>>>>> connected PC could easily handle the computations. It converged   
   in   
   >>>>>>>>>>>>>> less   
   >>>>>>>>>>>>>> than a second, always. The NRE was low because it took less   
   than two   
   >>>>>>>>>>>>>> weeks of my time and less than a day for the programmer, and we   
   didn't   
   >>>>>>>>>>>>>> need an expensive DSP programmer.   
   >>>>>>>>>>>>   
   >>>>>>>>>>>> Embarrassing.  Were any of the customers design team later   
   >>>>>>>>>>>> defenstrated?   
   >>>>>>>>>>>   
   >>>>>>>>>>> No, they were pretty good. It's the usual phenomenon where, in an   
   old   
   >>>>>>>>>>> German saying, you can't see the forest because of all the trees.   
   >>>>>>>>>>   
   >>>>>>>>>> Brainstorming is designed to get around that to some extent, but if   
   you   
   >>>>>>>>>> aren't used to thinking outside the box it's difficult to step back   
   far   
   >>>>>>>>>> enough to get outside the box.   
   >>>>>>>>>>   
   >>>>>>>>>   
   >>>>>>>>> My experience with brainstorm sessions is not good. The results are   
   >>>>>>>>> often encouraging but then hardly anything of it gets documented and   
   >>>>>>>>> typically none of it is implemented. All I need is a large whiteboard   
   >>>>>>>>> or a large piece of paper. Plus coffee or mate (having a mate right   
   now).   
   >>>>>>>   
   >>>>>>> It's a desperation measure to break up some kind of intellectual   
   log-jam.   
   >>>>>>>   
   >>>>>>> It isn't going to work all that often. Documenting it is a chore, but   
   it   
   >>>>>>> does need to be done   
   >>>>>>>   
   >>>>>>>> Brainstorming is great, done right.   
   >>>>>>>>   
   >>>>>>>> We sign and date our whiteboard scribbles and photograph them and   
   >>>>>>>> stash the pics in the project notes folder.   
   >>>>>>>   
   >>>>>>> Great for people who like visualisation.   
   >>>>>>   
   >>>>>> Or are literate.   
   >>>>>   
   >>>>> The illiterate can still look at pictures. Being able to write doesn't   
   >>>>> guarantee that you can organise your ideas into a chunk of text that   
   >>>>> other people will understand in the way that you want them to.   
   >>>>> Whiteboard scribbles aren't structured text.   
   >>>>   
   >>>> A photo of an FPGA register map with notes is a serious document.   
   >>>>   
   >>>> Given a group of smart people, a good brainstorm session is a way to   
   >>>> add (or multiply) their intelligence.   
   >>>>   
   >>>> But the personalities and the attitude have to be right. Some people   
   >>>> can't brainstorm.   
   >>>>   
   >>>> You attitude that most people are dumber than you are would (no doubt   
   >>>> has) poison a brainstorm session.   
   >>>   
   >>> It didn't. I don't make a habit of telling people that they are dumb. If   
   >>> they tell me stuff that is demonstrably wrong I do try to get them to   
   >>> recognise that they have to change their opinion, but it's a lot easier   
   >>> to do that in a collaborative fashion in face-to-face encounters.   
   >>> Some people do dig their heels in, but that doesn't happen in a well-run   
   >>> brainstorming session.   
   >>>   
   >>>> We've had junior people, even   
   >>>> interns, see something or say something that inspired cool ideas. The   
   >>>> audience must be grateful for all ideas, to encourage ideas.   
   >>>   
   >>> That's a well-known feature of brain-storming sessions   
   >>>   
   >>>> "That violates conservation of energy, but there might be something   
   >>>> there..."   
   >>>>   
   >>>> A brainstorm session is a way for a group of people to explore an   
   >>>> infinite solution space by using parallel processing.   
   >>>   
   >>> No finite brain, nor any loosely linked collection of finite brains, is   
   >>> going to explore an infinite solution space.   
   >>   
   >> Of course it can. It just can't find every possible solution.   
   >   
   >Only in the sense of wandering around like a lost sheep. Exploration is   
   >goal-directed and an infinite solution space has an infinite number of   
   >goals.   
   >   
      
   Exactly. Being goal-directed means that you have already decided the   
   direction to go in.   
      
   Maybe the best design is in the other direction.   
      
   Our policy is to always stay confused for a while early in a design,   
   and not latch on the the first idea (probably in a textbook) that   
   might work.   
      
   The techniques of exploring the greater solution space can be taught,   
   but not simply explained. Like I can't tell you how to play tennis in   
   an email.   
      
      
   John Larkin   
   Highland Tech Glen Canyon Design Center   
   Lunatic Fringe Electronics   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)