My local electronics shop has those little craftsman surplus DMMs. I bought
one and they stink. The leads will break with just a few not so careful
tugs, the V readings float all over the place, take a long time to settle,
and then will drift.
In short...don't waste your time. Go buy a cheap triplett DMM or something.
Thank you,
Greg Kutzbach
On Mon, Mar 8, 2010 at 1:53 PM, 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 <Homebrew_PCBs%40yahoogroups.com>
> [mailto:Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>]
> On Behalf Of alienrelics
> Sent: Monday, March 08, 2010 8:30 AM
>
> To: Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>
> Subject: [Homebrew_PCBs] Re: SMD caps - no marking - why?
>
> 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
>
> --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>
> <mailto:Homebrew_PCBs%40yahoogroups.com<Homebrew_PCBs%2540yahoogroups.com>>
> , Stefan Trethan
>
> <stefan_trethan@...> wrote:
> >
> > It doesn't seem to take 4mm test leads.
> > I have some meters with that kind of slot thingy, and never use them.
> > It's just so much more practical for me to use normal test leads.
> >
> > This is also useful:
> > <http://www.measuretronix.com/files/u2/Fluke-TL2x4-TWZ.jpg>
> >
> > You can also use half of a set of kelvin leads, like these:
> > <http://www.amptec.com/images/720pencil.jpg>
> > I use them often when I can't find the first type in my mess.
> >
> >
> > Both types of probes can now be bought very cheap direct from china,
> > no need to spend big $.
> >
> > If you need to measure a lot of caps there are test fixtures, probably
> > a bit expensive to buy but should be fairly easy to make yourself:
> > <http://www.datatec.de/shop/pix/a/n/1155936930-22235.jpg>
> >
> >
> > ST
> >
> > On Sun, Mar 7, 2010 at 4:35 PM, sailingto <sailingtoo@...> wrote:
> > > That is a nice looking meter with good specs. I guess it has a
> function to zero out the leads affect? And really not that much more
> than what I have - the one I have is $136 shipped here in USA. Kit is
> $30 less.
> > >
> > > If it came with tweezers for SMD stuff would really make it nice.
> I like the ohms function - is it really accurate? Have you checked any
> .1% resistors?
> > >
> > > Ken H>
> > >
> > >> I've got one these.
> > >>
> > >>
> http://cgi.ebay.com.au/TH2821-LCR-Meter-inductance-capacitance-and-R-1Kh
> z_W0QQitemZ280467653417QQcmdZViewItemQQptZLH_DefaultDomain_3?hash=item41
> 4d2cc329
> > >>
> > >> Its about another $50 more than than the L/C meter above, but its
> specs
> > >> are better. 4 port measurement at 100Hz,120Hz,1kHz or 10kHz with L,
> C &
> > >> R resolutions of 10nH, 100uOhm and 10fF respectively. It's only
> > >> disadvantages is the poorly thought out user interface.
> > >>
> > >
> > >
> > >
> > >
> > > ------------------------------------
> > >
> > > Be sure to visit the group home and check for new Links, Files, and
> Photos:
> > > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> > >
> > >
> > >
> > >
> >
>
> [Non-text portions of this message have been removed]
>
>
>
[Non-text portions of this message have been removed]