Andy N1YEW wrote:
>
> ok, so how would i do it with a pic?  i assume i would have to measure the
> decay time and know the resistor value and then compute it and display it.
>


You could make an LR oscillator and measure its period with the PIC  :-)


-- Rich




> andy
> ----- Original Message -----
> From: "Olin Lathrop" <olin_piclist@EMBEDINC.COM>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Thursday, May 31, 2001 7:17 AM
> Subject: Re: [EE]: measuring inductance
>
> > > how do i measure inductance of an inductor?
> >
> > I assume you want an answer other than "use an inductance meter, of
> course".
> >
> > The first thing I would do with an unknown inductor is measure the DC
> > resistance.  You will probably need to know this so you can account for it
> > when trying to measure the pure inductance.  In other words, you can think
> > of real inductors as a series combination of a resistor and an inductor.
> >
> > The simplest way to measure the inductance is to find the time constant
> with
> > a known resistance.  Connect a known resistor to a regulated +5V supply
> and
> > the other end to the inductor.  Look at the resistor/inductor junction
> > voltage with a scope.  It should show 5V for now because the other end of
> > the inductor is unconnected.  When the other end of the inductor is
> > connected to ground, you should see an exponential decay towards ground
> > (almost, depends on inductor series resistance).  Adjust the resistor
> value
> > so that time constant is reasonable.  You can now compute inductance from
> > (time constant) = RL.
> >
> >
> > ********************************************************************
> > Olin Lathrop, embedded systems consultant in Littleton Massachusetts
> > (978) 742-9014, olin@embedinc.com, http://www.embedinc.com
> >
> > --
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> >
> >
> >
>
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