Subject:
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Re: LEGO light sensor schematic
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Newsgroups:
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lugnet.robotics
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Date:
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Thu, 6 May 1999 14:06:49 GMT
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Viewed:
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907 times
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Michael,
Is your light sensor still in pieces? I was wondering if you could find a
moulded Lego part number for the upper half of the brick.
-John Van
Michael Gasperi <gasperi@alynk.com> wrote in message
news:FB614n.JBF@lugnet.com...
> In lugnet.robotics, lego-robotics@crynwr.com writes:
>
> > Just to clean up the schematic a bit you could flip R1 (75R) to the right
> > side of the Q4. I would also bring R8 (12R) in line with the LED.
> > This would then be a more standard drawing of a current source.
>
> OK, I fixed that and in the process discovered they should be PNPs.
> 3Hp83 is a BC857 GP PNP from Philips. Looks better now.
>
> > Is the detector a photo diode or a photo transistor?
>
> I think photo diode used in photovoltaic mode. It looks like it pushes the
> voltage down from that established by the LED.
>
> > > http://www.plazaearth.com/usr/gasperi/light.htm
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Message has 1 Reply:
 | | Re: LEGO light sensor schematic
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| (...) Sorry about that, I glued it back together with liquid plastic cement. I don't think it can take another operation and survive. I can't remember seeing a number inside and I was looking in there when you wedge the pc board in place. You might (...) (25 years ago, 6-May-99, to lugnet.robotics)
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Message is in Reply To:
| | Re: LEGO light sensor schematic
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| (...) OK, I fixed that and in the process discovered they should be PNPs. 3Hp83 is a BC857 GP PNP from Philips. Looks better now. (...) I think photo diode used in photovoltaic mode. It looks like it pushes the voltage down from that established by (...) (25 years ago, 3-May-99, to lugnet.robotics)
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