Homebrew PCBs

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
> >
>