Homebrew PCBs

I wrote it up on Electronics_101. Yahoogroups says they have found and fixed the search problem and have been updating groups with the fix, maybe Electronics_101 has been fixed...

Steve Greenfield

--- In Homebrew_PCBs@yahoogroups.com, "awakephd" <a_wake@...> wrote:
>
> Steve, is there a description on your site (or on Electronics-101) about how these circuits work? I think I get it ... maybe ... sorta ...
> 
> --- In Homebrew_PCBs@yahoogroups.com, "alienrelics" <alienrelics@> wrote:
> >
> > Thanks, that's my site and my designs.
> > 
> > FYI, the inductance meter I've not even breadboarded yet. So let me know how it works out, if you get to it before I do.
> > 
> > Steve Greenfield
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Jim Barnes" <jim@> wrote:
> > >
> > > Hi,
> > > 
> > >  
> > > 
> > > What a good idea! Also, check the other file on this site; it's a very
> > > similar inductance meter. That's more interesting to me because I have a
> > > way to measure capacitance ($7.98 new surplus Craftsman DMM I discovered
> > > at my local electronics shop. What a deal!) , but have no way to measure
> > > inductance at all. 
> > > 
> > >  
> > > 
> > > Jim
> > > 
> > >  
> > > 
> > > From: Homebrew_PCBs@yahoogroups.com
> >  
> > > 
> > > A couple of 555 timers makes a surprisingly accurate and sensitive
> > > capacitance meter. Uses your DMM in 200mV mode. In the lowest setting,
> > > 1mV = 1pF. Measures down to 0.1pF resolution, keeping in mind it isn't
> > > that accurate, but you can see the capacitance change as you wave your
> > > hands around.
> > > 
> > > http://www.polyphoto.com/tutorials/ElectronicCircuits/
> > > 
> > > Build it with parts from your junkbox for next to nothing.
> > > 
> > > Or if you can program microcontrollers, do the same thing in software.
> > > Regular clock followed by a monostable, the cap under test is in the
> > > monostable. Measure the time it takes to charge the capacitor.
> > > 
> > > Steve Greenfield
> > >
> >
>