[vcf-midatlantic] A little electronics hack

Mark Whittington markwhi at gmail.com
Mon Sep 30 13:00:56 EDT 2019


Ah, my mistake. Sorry for the false hope.

Best,

-Mark

On Mon, Sep 30, 2019 at 12:59 PM Tony Bogan <thebogans at mac.com> wrote:

> Mark, that’s the computer interface card. I believe Evan was talking about
> the controller board (Interface -a)
>
> http://4.bp.blogspot.com/-ixfYuILNd9I/U-3meTkPvkI/AAAAAAAAAYI/oqF0-8v-42w/s1600/LEGO_Controller_Top.jpg
>
> Tony
>
> Sent from my iPhone
>
> On Sep 30, 2019, at 11:16 AM, Mark Whittington via vcf-midatlantic <
> vcf-midatlantic at lists.vcfed.org> wrote:
>
> Looks like someone on this list has already done the legwork on this as of
> 2016...
>
> https://www.glitchwrks.com/2016/09/12/lego-logo-interface
>
> On Mon, Sep 30, 2019 at 9:13 AM Evan Koblentz via vcf-midatlantic <
> vcf-midatlantic at lists.vcfed.org> wrote:
>
> If you're interested in investigating further if you point us to
>
> schematics we can give suggestions.
>
>
> I am giving the box to Neville in early November (don't want to risk it not
>
> working before the Brickfair NJ event the first weekend of that month). He
>
> agreed to my request to make a schematic of it.
>
>
> The next step will be to have someone else take his schematic, build one,
>
> and send it back to me for testing. That'll prove that the box can in fact
>
> be built from just the plans. After that I'll post it on my website.
>
>
> A possible third stage would be to make modern improvements, if any ideas
>
> stand out.
>
>
> I'm only interested in the function, not in replicating the physical case.
>
> But what I would avoid is replacing the vintage computer with a
>
> microcontroller. I'm all for a better interface but strictly against some
>
> non-vintage computer experience.
>
>
>
>
>
> On Mon, Sep 30, 2019, 8:43 AM David Gesswein via vcf-midatlantic <
>
> vcf-midatlantic at lists.vcfed.org> wrote:
>
>
> It's called a 'crowbar' circuit.  Prevents things from burning up.
>
>
>
> What I normally called a crowbar circuit is the overvoltage protection
>
> where it intentionally shorts the output of the power supply. This sounds
>
> more like over current protection.
>
>
> What are common reasons why those stop working? Neville and I didn't
>
> see
>
> any obvious signs of damage to it.
>
>
> Either component value shift or failed component. You indicated that it
>
> is
>
> driving the motors better than it ever has. It may also be your motors
>
> are a heavier load than it was intended to drive.
>
>
> If you're interested in investigating further if you point us to
>
> schematics
>
> we can give suggestions.
>
>
>
> On Sun, Sep 29, 2019, 1:56 PM Mike Loewen <mloewen at cpumagic.scol.pa.us
>
>
> wrote:
>
>
> On Sun, 29 Sep 2019, Evan Koblentz via vcf-midatlantic wrote:
>
>
> Neville noticed something that I wouldn't have. The circuitry
>
> contains a
>
> safety mechanism to shut off all power if the current jumps too
>
> high,
>
> such
>
> as a kid inserting a paper clip. There's probably a technical name
>
> for
>
> that
>
> but I do not know it. Anyway, for unknown reasons this circuit was
>
> kicking
>
> in! He jumped it with an equal-length wire. :)
>
>
>    It's called a 'crowbar' circuit.  Prevents things from burning
>
> up.
>
>
>
> Mike Loewen                             mloewen at cpumagic.scol.pa.us
>
> Old Technology
>
> http://q7.neurotica.com/Oldtech/
>
>
>
>
>


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