Re: squeezing a field

On 26/10/2024 8:59 am, john larkin wrote:

On Fri, 25 Oct 2024 17:32:21 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
 

Bill Sloman <bill.sloman@ieee.org> wrote:
>

On 25/10/2024 7:37 pm, Liz Tuddenham wrote:

john larkin <jl@glen--canyon.com> wrote:
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On Thu, 24 Oct 2024 21:56:59 +0100, liz@poppyrecords.invalid.invalid
(Liz Tuddenham) wrote:
>

john larkin <jl@glen--canyon.com> wrote:
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On Thu, 24 Oct 2024 18:45:20 +0200, Lasse Langwadt <llc@fonz.dk>
wrote:

[...]

plugging numbers pulled out of thin air into LTSpice is better that
doing the actual measurement?

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It is for people who don't actually work with real parts.

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Peter Baxandall (of tone control and QUAD amplifier fame) claimed to use
analogue computing to work out his designs  i.e. He built prototypes and
measured them.

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You youngsters probably don't remember a time when there wasn't Spice.

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Hey!!!   Who are you calling a youngster?!!!      :-)
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I did some simulation in Basic-Plus, and it was a nuisance. My first
PC sim program was Tatum labs ECA, which required a typed netlist. But
it was pretty cool.

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I have a spreadsheet I wrote for calculating the relationships between
resistance, capacitance, frequency and time constant (put in two and the
others appear, put in three and the error% appears).   It also gives dB
loss below or above the 'cutoff' frequency.  Some years ago I also made
some lookup tables for combinations of 5% tolerance resistors in series
and parallel.
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Those and a pocket calculator are still the only 'computing' I use for
design work.

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No surprise there, though I am a bit surprised that you would admit it
in public.

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I don't understand why you use the word 'admit'.  I make my own tools to
meet my particular requirements, there is nothing shameful about that.

 You have been admonished by Sloman. Confess your errors and beg
forgiveness.
  Have you used LT Spice? It's easy to learn and is great fun. It makes
time for snacking and napping too.
 I even use it instead of a calculator for simple stuff like voltage
dividers and RC time constants and things.
 I can fiddle LC filters to at least third order. Sometimes 5th order,
until things diverge and explode.

But Williams and Taylor would let you do it better, if you could follow their advice.

LT Spice schematics can be screen-shot for things like block diagram
figures in manuals too.

There are other, better, schematic editors which you can also use that way.
--
Bill Sloman, Sydney