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]
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Re: [Homebrew_PCBs] Re: SMD caps - no marking - why?
2010-03-08 by Greg Kutzbach
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