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2010-03-05 by sailingto
Subject says it all - most all the SMD chips have ID marking - except for caps, some inductors, and maybe a few others. BUT resistors, transistors, large inductors, diodes, etc - almost everything has some sort of ID marking... Why does caps not have ID marking? It sure would help!! Even that tiny marking is ok - I can look under microscope to read. Thanks for info. Ken H>
2010-03-05 by Leon Heller
On 05/03/2010 17:22, sailingto wrote: > Subject says it all - most all the SMD chips have ID marking - except for caps, some inductors, and maybe a few others. BUT resistors, transistors, large inductors, diodes, etc - almost everything has some sort of ID marking... > > Why does caps not have ID marking? It sure would help!! Even that tiny marking is ok - I can look under microscope to read. It must be something to do with the ceramic material they are made from, I don't think that it can be written on using a laser. Leon -- Leon Heller G1HSM
2010-03-05 by sailingto
Is it as simple as that Leon? Can't write on material? I had not thought about that - ceramic is pretty hard. Any other ideas? Thanks for the info Leon, Ken H.
> It must be something to do with the ceramic material they are made from, > I don't think that it can be written on using a laser. > > Leon > -- > Leon Heller > G1HSM >
2010-03-05 by Stefan Trethan
I've seen some ceramic chip caps with writing on them, but it's very rare, about as rare as resistors without lettering. They could be laser marked, but I suppose nobody paid for it. ST
On Fri, Mar 5, 2010 at 6:51 PM, Leon Heller <leon355@...> wrote: > On 05/03/2010 17:22, sailingto wrote: >> Subject says it all - most all the SMD chips have ID marking - except for caps, some inductors, and maybe a few others. BUT resistors, transistors, large inductors, diodes, etc - almost everything has some sort of ID marking... >> >> Why does caps not have ID marking? It sure would help!! Even that tiny marking is ok - I can look under microscope to read. > > It must be something to do with the ceramic material they are made from, > I don't think that it can be written on using a laser. > > Leon > -- > Leon Heller > G1HSM > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > >
2010-03-05 by Adam Seychell
On 6/03/2010 5:37, Stefan Trethan wrote: > > > I've seen some ceramic chip caps with writing on them, but it's very > rare, about as rare as resistors without lettering. > Usually 0402 (1005 metric) resistors don't have markings. And I don't think any manufacture labels their 0201 (0603 metric) resistors. It means investment in a capacitance meter is kind of essential.
2010-03-05 by Piers Goodhew
I've seen it said that, for a given circuit board, SMD caps that are the same size and shape are probably the same value. I'm not in a position to test this (and may never need to) but has anyone heard this? True? False?
On Saturday, March 6, 2010, Adam Seychell <a_seychell@...> wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > On 6/03/2010 5:37, Stefan Trethan wrote: >> >> >> I've seen some ceramic chip caps with writing on them, but it's very >> rare, about as rare as resistors without lettering. >> > > Usually 0402 (1005 metric) resistors don't have markings. And I don't > think any manufacture labels their 0201 (0603 metric) resistors. > > It means investment in a capacitance meter is kind of essential. > > > > > > > > > > > > > > > > > > > > >
2010-03-05 by Leon Heller
On 05/03/2010 22:26, Piers Goodhew wrote: > I've seen it said that, for a given circuit board, SMD caps that are > the same size and shape are probably the same value. I'm not in a > position to test this (and may never need to) but has anyone heard > this? True? False? False! Leon -- Leon Heller G1HSM
2010-03-05 by Harvey White
On Sat, 6 Mar 2010 09:26:00 +1100, you wrote: >I've seen it said that, for a given circuit board, SMD caps that are >the same size and shape are probably the same value. I'm not in a >position to test this (and may never need to) but has anyone heard >this? True? False? > False. (easy to make false, one exception works). I can buy 1206 (roughly 0.120 by 0.060) capacitors in any value from at least 4.7 pf to 1.0 ufd. In fact, I have and they're in storage for the parts I use. In terms of electrolytics, also false, since there's only 3 - 4 Kemet sizes, and many more values. 1ufd and 10 ufd at 16 volts are the same size, IIRC. Capacitor size for electrolytics goes up with value and working voltage. If you're going to deal with capacitors and resistors, at the least, you need a pair of tweezers that connect to your DMM. Better would be a self contained meter. They range from moderately expensive (with less features) to very expensive (with lots of features). Harvey
2010-03-06 by sailingto
That was one of the BIG reasons I purchased a L/C meter IIB by AADE (Almost All Digital Electronics) was to check SMD chips. Problem is, it just doesn't do SMD caps very well - does leaded caps just fine, but SMD... not so good. I have talked to the guy who say "Send it back for calibration", I've got to get that done. Thanks for all the info - sounds like there is no real reason other than "they don't do it". Ken H>
> If you're going to deal with capacitors and resistors, at the least, > you need a pair of tweezers that connect to your DMM. > > Better would be a self contained meter. They range from moderately > expensive (with less features) to very expensive (with lots of > features). > > Harvey >
2010-03-06 by Sz G
Hey Ken, Most probably you know exactly what you're doing, so excuse me for this question in advance. I just wanted to ask if you tried to check those little bastards in the immediate vicinity of the meter or on (longer than, let's say, an inch long) leads, as in the latter case, your readout will be definitely affected by that, especially when dealing with devices as small as a 0805. HTH. Gabor ________________________________ From: sailingto <sailingtoo@...> To: Homebrew_PCBs@yahoogroups.com Sent: Sat, March 6, 2010 3:52:25 AM Subject: [Homebrew_PCBs] Re: SMD caps - no marking - why? That was one of the BIG reasons I purchased a L/C meter IIB by AADE (Almost All Digital Electronics) was to check SMD chips. Problem is, it just doesn't do SMD caps very well - does leaded caps just fine, but SMD... not so good. I have talked to the guy who say "Send it back for calibration" , I've got to get that done. Thanks for all the info - sounds like there is no real reason other than "they don't do it". Ken H>
> If you're going to deal with capacitors and resistors, at the least, > you need a pair of tweezers that connect to your DMM. > > Better would be a self contained meter. They range from moderately > expensive (with less features) to very expensive (with lots of > features). > > Harvey >
2010-03-06 by Stefan Trethan
The AADE meter is not terribly useful for everyday capacitance measurements, it's more for HF component work. Instead use a low frequency meter, like a handheld multimeter with capacitance range. They will work fine for SMD caps even with standard test leads. Of course at some point the lead capacitance will be a factor, for very small values. ST
On Sat, Mar 6, 2010 at 1:29 PM, Sz G <the6hu8b@...> wrote: > Hey Ken, > > Most probably you know exactly what you're doing, so excuse me for this question in advance. I just wanted to ask if you tried to check those little bastards in the immediate vicinity of the meter or on (longer than, let's say, an inch long) leads, as in the latter case, your readout will be definitely affected by that, especially when dealing with devices as small as a 0805. > > HTH. > > Gabor > > ________________________________ > From: sailingto <sailingtoo@gmail.com> > To: Homebrew_PCBs@yahoogroups.com > Sent: Sat, March 6, 2010 3:52:25 AM > Subject: [Homebrew_PCBs] Re: SMD caps - no marking - why? > > > That was one of the BIG reasons I purchased a L/C meter IIB by AADE (Almost All Digital Electronics) was to check SMD chips. Problem is, it just doesn't do SMD caps very well - does leaded caps just fine, but SMD... not so good. > > I have talked to the guy who say "Send it back for calibration" , I've got to get that done. > > Thanks for all the info - sounds like there is no real reason other than "they don't do it". > > Ken H> > >> If you're going to deal with capacitors and resistors, at the least, >> you need a pair of tweezers that connect to your DMM. >> >> Better would be a self contained meter. They range from moderately >> expensive (with less features) to very expensive (with lots of >> features). >> >> Harvey >> > > > > > > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > >
2010-03-06 by sailingto
Gabor - I have tried both ways, checking caps at the end of 6 inch leads - the AADE meter has compensation to null out length of leads, and I've also rigged a copper board across the posts so the lead length is as close to zero as you can get. As I said, the meter works with leaded components pretty good, it's only on SMD chips I have a problem. Ken H> --- In Homebrew_PCBs@yahoogroups.com, Sz G <the6hu8b@...> wrote:
> > Hey Ken, > > Most probably you know exactly what you're doing, so excuse me for this question in advance. I just wanted to ask if you tried to check those little bastards in the immediate vicinity of the meter or on (longer than, let's say, an inch long) leads, as in the latter case, your readout will be definitely affected by that, especially when dealing with devices as small as a 0805. > > HTH. > > Gabor
2010-03-06 by lists
In article <afa365fa1003060906g178a5f0ana16cc2fe835847a2@...>, Stefan Trethan <stefan_trethan@...> wrote: > The AADE meter is not terribly useful for everyday capacitance > measurements, it's more for HF component work. > Instead use a low frequency meter, like a handheld multimeter with > capacitance range. They will work fine for SMD caps even with standard > test leads. Of course at some point the lead capacitance will be a > factor, for very small values. I use one of these and it works very well. I also have the SMD probe set. http://www.peakelec.co.uk/acatalog/jz_lcr40.html No conection with the above company, just a satisfied customer. -- Stuart http://www.torrens.org.uk/ZFC/gallery/winsor.html
2010-03-07 by Adam Seychell
On 6/03/2010 13:52, sailingto wrote: > > > That was one of the BIG reasons I purchased a L/C meter IIB by AADE > (Almost All Digital Electronics) was to check SMD chips. Problem is, it > just doesn't do SMD caps very well - does leaded caps just fine, but > SMD... not so good. > > I have talked to the guy who say "Send it back for calibration", I've > got to get that done. > > Thanks for all the info - sounds like there is no real reason other than > "they don't do it". > > Ken H> I've got one these. http://cgi.ebay.com.au/TH2821-LCR-Meter-inductance-capacitance-and-R-1Khz_W0QQitemZ280467653417QQcmdZViewItemQQptZLH_DefaultDomain_3?hash=item414d2cc329 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.
2010-03-07 by sailingto
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-1Khz_W0QQitemZ280467653417QQcmdZViewItemQQptZLH_DefaultDomain_3?hash=item414d2cc329 > > 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. >
2010-03-07 by Stefan Trethan
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-1Khz_W0QQitemZ280467653417QQcmdZViewItemQQptZLH_DefaultDomain_3?hash=item414d2cc329 >> >> 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 > > > >
2010-03-08 by alienrelics
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, 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-1Khz_W0QQitemZ280467653417QQcmdZViewItemQQptZLH_DefaultDomain_3?hash=item414d2cc329 > >> > >> 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 > > > > > > > > >
2010-03-08 by sailingto
Steve, that is a very good idea - I'm not all that concerned about true accuracy, just so I can tell a .1 from a .01 cap. You mention seeing change as you wave your hands about - is it stable enough? I would be interested in building one of those - I do fool around with uC some - that would make a neat project to display on a LCD. Thanks for posting. Ken H> --- In Homebrew_PCBs@yahoogroups.com, "alienrelics" <alienrelics@...> wrote:
> > 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
2010-03-08 by Jim Barnes
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 [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of alienrelics Sent: Monday, March 08, 2010 8:30 AM To: Homebrew_PCBs@yahoogroups.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 <mailto:Homebrew_PCBs%40yahoogroups.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]
2010-03-08 by Greg Kutzbach
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]
2010-03-08 by alienrelics
Thanks, that's my design. I've built a few of them and sold them, first one around 1980 but those with 50uA meter movements. That one I built in 1985 with some parts I had on hand, so it is built with a surplus control that has a volume control (used for zero set to cancel wire capacitance) on a 1/8 inch shaft in the center of a SP5T rotary switch. The case is a clear orange plastic box, I think it had a bottle of perfume in it at some time. Yes, it is very stable. Use a 5V regulator. I put a momentary pushbutton on mine for power, it draws very little power so a 9V alkaline battery has lasted years. I started building a mini version to fit in the pocket of one of those Radio Shack pocket DMMs, using supermagnets and some tiny reed switches for the range selector. Never quite completed it, now I'd use a PIC with capacitance switches and its own LCD display. Actually I'm working on a design for a combo capacitance meter and ESR to fit into a compact case. Yes, I know I can buy one, but the point is for -me- to build it. If we're going to talk more about the design, we should move over to the Electronics_101 list. Steve Greenfield --- In Homebrew_PCBs@yahoogroups.com, "sailingto" <sailingtoo@...> wrote:
> > Steve, that is a very good idea - I'm not all that concerned about true accuracy, just so I can tell a .1 from a .01 cap. You mention seeing change as you wave your hands about - is it stable enough? > > I would be interested in building one of those - I do fool around with uC some - that would make a neat project to display on a LCD. > > Thanks for posting. > > Ken H> > > --- In Homebrew_PCBs@yahoogroups.com, "alienrelics" <alienrelics@> wrote: > > > > 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 >
2010-03-08 by alienrelics
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 >
2010-03-09 by awakephd
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 > > >
2010-03-09 by alienrelics
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 > > > > > >
2010-03-09 by sailingto
It sure would be nice to have the search feature fixed in all the yahoo groups!!! BTW Steve, that is a good circuit and I do thank for offer of more assitance over on Electronics_101, but right now I've got about 3 or 4 projects in head of the cap meter. I do hope to look at it more indepth later on. Thanks for all the GREAT contributions from yourself and the many other folks who make the groups GREAT. I have learned LOT. Ken H. --- In Homebrew_PCBs@yahoogroups.com, "alienrelics" <alienrelics@...> wrote:
> > 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 ... >
2010-03-10 by alienrelics
Well, if you decide to go look, I already found two of the posts and put links in this message: http://groups.yahoo.com/group/Electronics_101/message/59728 Steve Greenfield --- In Homebrew_PCBs@yahoogroups.com, "sailingto" <sailingtoo@...> wrote:
> > It sure would be nice to have the search feature fixed in all the yahoo groups!!! > > BTW Steve, that is a good circuit and I do thank for offer of more assitance over on Electronics_101, but right now I've got about 3 or 4 projects in head of the cap meter. I do hope to look at it more indepth later on. > > Thanks for all the GREAT contributions from yourself and the many other folks who make the groups GREAT. I have learned LOT. > > Ken H. > > --- In Homebrew_PCBs@yahoogroups.com, "alienrelics" <alienrelics@> wrote: > > > > 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 ... > > >
2010-03-10 by John McCormick
Does anyone have a vacuum pickup tool suggestion?
I really want one with a solenoid that turns the air on/off.
I was thinking I could throw it on my sherline mill and place some objects. I would use the rotary table to spin the pcb and the Z axis to place the part.
This would just be manual and only for fine pitch devices.
I can put down 0603 with tweezers but fine pitch devices < 1mm I have problems getting into place without smearing the solder paste.
My technique usually involves dropping it down then tapping it gently from the side until I get it on.
Again with ICs my problem is that this tends to smear the paste.
Any other suggestions? I want to be able to do <.5mm pitch QFP pieces.
[Non-text portions of this message have been removed]2010-03-10 by Stefan Trethan
Typically they don't have a solenoid valve, just a hole on the handle to vent the vacuum (or not). It would be trivial to add a solenoid valve. You would prefer the variety which vents the output, not just on/off. Also you want a valve that doesn't need pilot pressure or has a separate port for pilot pressure (which you would hook to an air supply). Actually, just about everything about vacuum pickup tools is simple. You can easily build one using just about any vacuum source and a length of hose. ST
On Wed, Mar 10, 2010 at 8:57 PM, John McCormick <mcjonster@...> wrote: > > Does anyone have a vacuum pickup tool suggestion? > > I really want one with a solenoid that turns the air on/off. > > I was thinking I could throw it on my sherline mill and place some objects. I would use the rotary table to spin the pcb and the Z axis to place the part. > > This would just be manual and only for fine pitch devices. > > I can put down 0603 with tweezers but fine pitch devices < 1mm I have problems getting into place without smearing the solder paste. > > My technique usually involves dropping it down then tapping it gently from the side until I get it on. > > Again with ICs my problem is that this tends to smear the paste. > > Any other suggestions? I want to be able to do <.5mm pitch QFP pieces. > > > > > [Non-text portions of this message have been removed] > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > > >
2010-03-10 by sailingto
Thanks for the info steve. I spent a bit of time reading the links today (lunch hour!). The more I read about this, the more I wish to build one using something along your design. I'm not real knowledgable about this stuff, but do enjoy working/building. I really do need to get retired so I've time to work on all these neat projects :) Ken H. --- In Homebrew_PCBs@yahoogroups.com, "alienrelics" <alienrelics@...> wrote:
> > Well, if you decide to go look, I already found two of the posts and put links in this message: > http://groups.yahoo.com/group/Electronics_101/message/59728 > > Steve Greenfield
2010-03-10 by John Coppens
On Wed, 10 Mar 2010 21:08:36 +0100 Stefan Trethan <stefan_trethan@...> wrote: > Typically they don't have a solenoid valve, just a hole on the handle > to vent the vacuum (or not). Just came across to a selfbuilt pickup tool: http://hackaday.com/2010/03/03/vacuum-pick-and-place-for-smd-parts/ it uses a modified aquarium pump. Very simple and well documented. John