From: Sean Breheny <shb7@cornell.edu>
To: Microcontroller discussion list - Public. <piclist@mit.edu>
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Date: Sun, 19 Jan 2020 08:21:21 -0800
Subject: Re: [EE] Magnetic lock
Thread-Topic: [EE] Magnetic lock
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If the electromagnet uses AC then it will indeed draw less current when it
is closed against the piece of metal it attracts. This is because there is
no longer an air gap in the magnetic circuit so the inductance is higher.

On Sat, Jan 18, 2020, 8:43 PM mike brown <mike@n5qmg.com wrote:

> In my experience, the electromagnet appears to draw less current when
> latched to the metal plate.  This is an unscientific observation based up=
on
> the temperature of the magnet increasing when not latched to the steel
> plate.  Amazing that they can generate such a strong holding force using
> three watts of power as long as the two parts perfectly mate to each othe=
r.
>
> On Sat, Jan 18, 2020, 19:07 Bob Blick <bobblick@outlook.com> wrote:
>
> > Admin message to Allen, since his email address seems to reject direct
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