Subject:
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Re: LEGO Electro-magnet
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Newsgroups:
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lugnet.robotics
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Date:
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Sun, 15 Apr 2001 18:06:45 GMT
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Viewed:
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1886 times
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Rainer Balzerowski <balze2@gmx.net> wrote in message
news:GBuGyD.Fzn@lugnet.com...
> Hi Philip,
>
> may be, but I would chose the safe side (We did with our 6.270 board and used 2
> diodes, who cares about 2 diodes).
>
> BTW I'm not sure what happens with the energy in an electro motor. I can
> imagine that this energy (resulting in a magnetic field) is used to turn the
> anchor (is it the right word in english for the part that turns in a electro
> motor ? :-) ). But I have no knowledge of the behavior of electro-motors.
>
> Rainer
I've found a book which mentions this, and talks about using 'flyback
diodes' when "switching inductive loads such as motors" -- it appears that
motors do have this problem.
Apparently the RCX uses three ELEX 10402B motor driver chips, and the
description on their web-site
(http://ecom.melexis.com/mlx_profile.cgi?BU=Standard_Product_Actuator_ICs&fa
mily=MLX10402) says:
"The IC drives directly small DC inductive or active loads like electric
motors, lamps, etc." . . . "The current of the output-drivers is limited for
protection against all kind of overload and short-circuit conditions, and
this in the whole supply voltage and temperature range. The outputs 'M1' and
'M2' are on-chip diode-protected against motor inductances (Nominal values
of 12mH and 12 Ohm)."
so they are definitely diode-protected, and you don't have to worry about
melting your RCX :-)
--
Philip Taylor
http://robowarriors.ultrastore.com
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Message has 1 Reply: | | Re: LEGO Electro-magnet
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| Well, good work Philip. Good to be sure about this. I was only afraid that you'll frie your RCX, because of not knowing this effect. Regards, Rainer P.S.: Learned something, not unload diode, but flyback diode ! ;-) (...) (24 years ago, 15-Apr-01, to lugnet.robotics)
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Message is in Reply To:
| | Re: LEGO Electro-magnet
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| Hi Philip, may be, but I would chose the safe side (We did with our 6.270 board and used 2 diodes, who cares about 2 diodes). BTW I'm not sure what happens with the energy in an electro motor. I can imagine that this energy (resulting in a magnetic (...) (24 years ago, 15-Apr-01, to lugnet.robotics)
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