Subject:
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lego cap, polarity, etc
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Newsgroups:
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lugnet.robotics
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Date:
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Tue, 27 Mar 2001 22:15:15 GMT
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Original-From:
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Bruce Boyes <BBOYES@SYSTRONIXantispam.COM>
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Viewed:
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460 times
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At 10:25 3/27/2001 -0500, John Barnes wrote:
> This whole Lego capacitor thing strikes me as somewhat intriguing.
>
> The super-caps, which are doubtless used, absolutely cannot be charged
> backwards, they have to have the correct polarity. And all the Lego
> electrical "stuff" like the RCX sensors, have been carefully designed to
> be insensitive to polarity. So;
>
> I assume the Lego capacitor has some kind of bridge rectifier in it to
> ensure that the capacitor component itself is charged with the correct
> polarity. So;
>
> How do they get the power back out? Is there a seperate in and out
> connector? Is there some very clever circuitry which "remebers" which
> way the inputs were connected so it will discharge back out of the
> input terminals with the correct output polarity?
I don't have one, but can make some guesses. A bridge only works with an
AC input - it can't correct the polarity of a DC input. So the Lego cap
either has an AC input possibly through a bridge or a DC input which is the
correct polarity by means of its connectors.
I'm curious too.
Bruce
------- WWW.SYSTRONIX.COM ----------
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High speed 8051 systems
+1-801-534-1017 Salt Lake City, USA
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Message has 2 Replies:
 | | Re: lego cap, polarity, etc
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| (...) connectors. Uh, a bridge wouldn't be very good if it didn't handle inputs that switched polarities. A bridge should work just fine with a DC input of any polarity (of course for any DC input, only half of the bridge is actually being used). (...) (23 years ago, 27-Mar-01, to lugnet.robotics)
| | | Re: lego cap, polarity, etc
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| (...) Right, what I was trying to say is that a bridge can't 'invert' a DC input of one polarity to make an output of another polarity - it can't "correct" anything, a diode can only conduct or not conduct. All a bridge can do is route the given DC (...) (23 years ago, 27-Mar-01, to lugnet.robotics)
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Message is in Reply To:
| | Solar cells and caps: lego part #s
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| This whole Lego capacitor thing strikes me as somewhat intriguing. The super-caps, which are doubtless used, absolutely cannot be charged backwards, they have to have the correct polarity. And all the Lego electrical "stuff" like the RCX sensors, (...) (23 years ago, 27-Mar-01, to lugnet.robotics)
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