[sdiy] favorite Youtube genre - "old guys repairing electronics"

Sun Nov 1 18:02:25 CET 2020

Seeing this discussion, I feel compelled to share my process for making
PCBs.  I'll use a fairly simple one (a dual voltage-controlled crossfader)
as an example.

First, the schematic, drawn in Multisim (for one of two identical channels):

Next, the Layout -- Red is +15V, Black is -15V, Green is GND, Yellow is +5V,
Orange is -5V, and (mostly) pink is everything else, although I do use other
colours for clarity on occasion.  All resistors and diodes are 0.4" unless
it absolutely cannot be avoided.  The thick dark blue lines are wire
jumpers:

For this circuit, this layout took me probaby about half an hour to do.  Of
course, I'm starting from an existing layout, so all the parts are already
made and it's just a matter of moving things around (on a "Snap-to-Grid"
basis), and possibly opening up another layout file to get a part that I
needed that wasn't on the one I started with.  Actually organizing the
circuit from the schematic for a circuit like this is very fast for me,
because I always use the same layout scheme for analog circuits (a 2.1" wide
PCB, chips down the middle, then one row on either side for stability caps
and other connections, then the resistors and diodes with up to 3 traces
running underneath for signal flow, then the connector row, then ground).

Next, I copy this and erase all the traces, just leaving the Parts.  From
this, I can copy all the parts over to the BOM and line them up for quick
and easy retrieval from the parts bins:

Next, I copy the Layout again and remove all the parts, then build up the
Traces using a scheme involving up to 5 different layers.  For this part,
the erasing of the parts takes the most time.  Building up the trace layers
for a board this size takes me less than two minutes.  Note how the power
traces are thicker than the signal traces.  Also note the rounded corners on
all the traces.

Next, I build up the Pads by superimposing special circular images over all
the connections on the Parts picture.  Again, I'm always starting from
another layout.  This part generally takes less than two minutes.  Mounting
holes, power headers, MTA connectors, and parts all have their own pad
sizes:

The rest will be shown in a subsequent message (cuz otherwise it'll be too
long for Synth-DIY).

  _____  

From: Synth-diy [mailto:synth-diy-bounces at synth-diy.org] On Behalf Of
sleepy_dog at gmx.de
Sent: Saturday, October 31, 2020 4:57 AM
To: synth-diy at synth-diy.org
Subject: Re: [sdiy] favorite Youtube genre - "old guys repairing
electronics"

[CAUTION: Non-UBC Email] 

Heh. If I need something quickly, cant wait for PCB, but also it does have
certain physical dimension requirements,
then I do get really "boring" and do "plan" perfboard - "what is the fun in
that" someone asked - indeed, what is the fun in that sort of tedious,
repetitive work alltogether?
Better make it as short as, and least error prone possible. It's so much
easier to reason about misbehavior of a circuit if it actually matches what
you have drawn - at least from the obvious (not parasitic) components and
their supposed connections.
While it's perhaps reasonabnly unlikely to make mistakes if you have all the
space in the world and basically solder together the circuit as-is-drawn on
some big ass perfboard, also leaving lots of room for adding more stuff to
experiment,
as things get more crowded and less intuitively placed, I found the
following to be helpful:

First of all, esp. for single-sided perfboard, I like to combine THT ICs
with SMT 0805 passives, as you can often put them comfortably between legs
and under the IC (on the bottom side of the board), that already saves a lot
of space - and wiring effort.
There are also these, often green, plated-through double-sided perfboards -
may reduce the insulated connections you have to make (which take longer due
to the need for burning away the insulation / tinning), e.g. all GND with
silver wire on the bottom, +V on the top side, or so, other nets with
insulated wire, where unconnected crossings would be at least.

Also, in the type of scenario where I would, if I could, prefer a small PCB,
but don't want to wait,
I might already have a captured schematic in my chosen EDA software anyway -
or if it's small, I'll just do it quickly.
Then convert to PCB, and usually don't route anything, or at best a few
special traces to mark special preferences.

I put that on my small-ish tablet with stylus support, that actually fits on
my crowded soldering bench.
that also runs the EDA software. Then I:

foreach non-GND-net:
    highlight net in PCB software
    connect all net points in circuit with insulated "coil wire",
point-to-point
    hide net's ratlines (or color existing traces) to make visible what's
still TODO - this shrinks more and more, and you can see the light at the
end of the tunnel

This, for me anyway, proved much less error prone than staring on a paper
printout and comparing it with the current physical as-is schematic all the
time (even when pencil checking traces ;) ).
Can basically do that half-asleep without making a mistake. (just make sure
to display the bottom side mirrored appropriately :D)

Then for the GND net I do the above, except I user silver coated copper
wire, a bit sturdier, and wherever possible, do not cut, but bend around
corners, using one long piece of wire across many connections, saving some
work steps. The silver wire will be over all those coil wires, holding them
in place a bit better, esp. longer ones, and make it less likely that you
will rip off any connection by accidentally grabbing too hard anywhere.

- Steve

Am 31.10.2020 um 11:23 schrieb ShedSynth:

Hi all.

I use perfboard, but I don't try to make it into a PCB.

I wire point-to-point with single core Kynar wire, normally used for
wire-wrapping.

I use blue, black, red and yellow on the back for -12V, GND, +5V and +12V.

I use green for all signals, always on the component side.

I lay out the big things like pots, DIL sockets and capacitors on the board
itself, and always try to leave rows of 4 holes to place resistors flat.

Then I follow the schematic, which might take several days - this isn't a
mass-production process.

I separate each functional block with a pair of pins + a jumper so I can
test on the scope as I go and also so I can bodge blocks of completed
circuits into something else.

Hope this might help somebody,

Al

If the picture comes through, it's most of a Thomas Henry MAXIMUS 3340 VCO.

The front is just as ugly.

From: Synth-diy  <mailto:synth-diy-bounces at synth-diy.org>
<synth-diy-bounces at synth-diy.org> On Behalf Of Timothy Burns
Sent: 30 October 2020 15:17
Cc: SYNTH DIY  <mailto:synth-diy at synth-diy.org> <synth-diy at synth-diy.org>
Subject: Re: [sdiy] favorite Youtube genre - "old guys repairing
electronics"

Good lord, I wish I watched this yesterday. Also what the heck, did he plan
before he started soldering in components? What fun is that?

Thanks for the suggestions of video and audio channels, this will be great
to have on hand as I re-solder everything from the last 36 hours. 

I'm not saying I'm going to start now, but does anyone have suggestions
software or shortcuts for planning perfboard builds? Fritzling? (Asking for
a friend.) 

Thanks All!

Tim

On Fri, Oct 30, 2020 at 10:34 AM Ryan B8S <ryan at pimpdroid.com> wrote:

Not an old guy, but I can't believe no one mentioned Synth Chaser at Synth
Chaser dot com.

https://www.youtube.com/c/SynthChaser/videos

My favorite youtube channel by an order of magnitude.

On Wed, Oct 21, 2020 at 7:08 PM David Simpson <davidosimpson at gmail.com>
wrote:

I recently found this video and was astonished by the skill, technique
quietude ala Bob Villa.

How to solder grid style PCB / 555 PWM DC-motor
<https://youtu.be/_ypW45Y8VSs> driver (EEEL1-3)

What are your favorite channels for informative/instructive electronics
repair? Preferable those who don't yell or are in a constant state of
outrage...

-- 

david o. simpson | cameraperson | binarymob.com | earth

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