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Subject: 
Re: LEGO Electro-magnet
Newsgroups: 
lugnet.robotics
Date: 
Sat, 21 Apr 2001 00:56:07 GMT
Viewed: 
1910 times
  
In lugnet.robotics, Philippe Hurbain writes:
To be more precise: in passive mode there is a 10K pullup (to 5V)
introducing some current (0.45 mA) in the coil. This small current may be
enough to retain something stuck to the magnet...


I think this could happen. Even without this low current present all the
time, an electro magnet powered by a DC supply always in the same direction
can develop a residual magnetic field (samll things would stay stuck even
after the electro magnet is completely off).

Using a motor port would let you invert the polarity every time you power
the electro magnet, thus reducing the chances of residual magnetism.

Greetings,
David



Message is in Reply To:
  Re: LEGO Electro-magnet
 
To be more precise: in passive mode there is a 10K pullup (to 5V) introducing some current (0.45 mA) in the coil. This small current may be enough to retain something stuck to the magnet... Philo (...) (24 years ago, 20-Apr-01, to lugnet.robotics)

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