[vcf-midatlantic] A little electronics hack

Tony Bogan thebogans at mac.com
Mon Sep 30 12:59:26 EDT 2019


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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