Subject:
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Re: External Power Port Problem..?
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Newsgroups:
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lugnet.robotics
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Date:
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Wed, 1 Dec 1999 23:23:17 GMT
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Viewed:
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464 times
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In lugnet.robotics, "Issac Merkle" <the_gaff@hotmail.com> writes:
> Esteemed Colleagues,
>
> I have two RCXs, both of which have stopped responding to power applied
> to the external power port. With batteries, they function correctly;
> with a 9.6v Lithium Ion battery pack attached to the external port,
> nothing. This has not always been the case; in the past, I have
> successfully powered my RCXs by an AC adaptor and by the aforementioned
> 9.6v battery pack. Nothing unusual happened that would have damaged the
> units that I am aware of.
>
> Having contacted LEGO support, I am being told that they will generously
> replace the RCX units "this time". If any of my RCXs fail in the future
> with my having used non-DACTA AC adaptors, they will not replace them.
> They feel they "have to draw the line somewhere". The best rationale for
> their pushing the blame on me that they have offered is that the
> "polarity may have been reversed". My attempts to dismiss that as
> nonsense with regard to the AC marking on the RCX have fell on
> uneducated ears; I don't think the woman with whom I have been speaking
> has a technical bone in her body. I was thinking that someone else had
> made some mention of RCX external power port failure. Anyone..?
>
> Does this seem a reasonable response from LEGO? My standpoint is that
> the power requirements for the RCX units are clearly printed on the RCXs
> themselves, and that a rechargable 9.6v pack is well within those limits
> and, indeed, almost the same as powering the units with batteries. The
> polarity seems a non-issue to me. I am frankly incensed; having spent
> ~$2000 on LEGO sets since last November, and considering my continuing
> participation in the Mindstorms threaded discussion forum helping out
> newbies, I feel I should be a valued customer by now.
>
> Your comments are appreciated (sooner the better; Luwanda's supervisor
> should be calling me any time now).
I wonder if this is why the power port has disappeard from the Mindstorms
1.5...
The suspicion is, that the genuine supply has a relatively high internal
resistance, and therefore 'current limits' if a lot is drawn from the motor
outputs, preventing damage to the supply in the brick. Your batteries will
have a significantly lower resistance in this regard, and may deliver
instantaneous currents that can damage this circuitry. If this is why the
power input is being dropped, it represents a stupid solution, rather than re-
designing the input circuitry to be self protection...
Best Wishes
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Message has 1 Reply:
 | | RE: External Power Port Problem..?
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| Although I didn't see an "Use only Lego approved power supplies with the external power connector" in the manual, I believe Lego has no obligation to fix your RCX brick. The connector is for an external AC power pack, not a custom Lithium Ion DC (...) (25 years ago, 2-Dec-99, to lugnet.robotics)
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Message is in Reply To:
| | External Power Port Problem..?
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| Esteemed Colleagues, I have two RCXs, both of which have stopped responding to power applied to the external power port. With batteries, they function correctly; with a 9.6v Lithium Ion battery pack attached to the external port, nothing. This has (...) (25 years ago, 26-Mar-99, to lugnet.robotics)
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