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polymer aluminum cap

Started by John Larkin September 17, 2012
On Wednesday, September 19, 2012 4:58:27 PM UTC-7, miso wrote:
> A 50 ohm source is not low enough to jam current into a cap.
If one wants to measure capacitance (a linear property), or resistance (aka ESR), which is another linear property, there's no 'not low enough' problem. You apply a signal, you get the measurement. If there's a NONLINEAR property, like from boiling electrolyte, higher pulse currents might find it. Is that what you're after?
On Wed, 19 Sep 2012 23:52:05 -0700 (PDT), whit3rd <whit3rd@gmail.com>
wrote:

>On Wednesday, September 19, 2012 4:58:27 PM UTC-7, miso wrote: >> A 50 ohm source is not low enough to jam current into a cap. > >If one wants to measure capacitance (a linear property), or resistance >(aka ESR), which is another linear property, there's no 'not low enough' >problem. You apply a signal, you get the measurement. > >If there's a NONLINEAR property, like from boiling electrolyte, higher pulse >currents might find it. Is that what you're after?
I did use an external scope trigger, and 16x signal averaging, to get a clean waveform at 2 mv/div. More current would have given more signal, a bigger step on the screen, which would have been better if I was looking for more accuracy. I suppose I could have turned the generator up, to get a 200 mA step instead of 100. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
On 9/20/2012 2:52 AM, whit3rd wrote:
> On Wednesday, September 19, 2012 4:58:27 PM UTC-7, miso wrote: >> A 50 ohm source is not low enough to jam current into a cap. > > If one wants to measure capacitance (a linear property), or resistance > (aka ESR), which is another linear property, there's no 'not low enough' > problem. You apply a signal, you get the measurement. > > If there's a NONLINEAR property, like from boiling electrolyte, higher pulse > currents might find it. Is that what you're after?
Resistance, inductance and capacitance are concepts that we use to describe what we see in the physical world. They apply very well to some things (like a wire wound coil or a composition resistor), pretty well to some things (capacitors for example) and not very well at all to still others (semiconductors are good examples). Capacitors are not described perfectly by a model using only resistance, capacitance and inductance. There are non-linear effects caused by the material involved doing things other than simply polarizing. That is why there are different capacitor types, they are non-perfect in different ways. You know all of this. Why are you guys arguing over nothing? Aren't there more productive things to discuss? Or is this some sort of compulsion for you guys? http://xkcd.com/386/ Rick
On Thu, 20 Sep 2012 10:20:19 -0400, rickman <gnuarm@gmail.com> wrote:

>On 9/20/2012 2:52 AM, whit3rd wrote: >> On Wednesday, September 19, 2012 4:58:27 PM UTC-7, miso wrote: >>> A 50 ohm source is not low enough to jam current into a cap. >> >> If one wants to measure capacitance (a linear property), or resistance >> (aka ESR), which is another linear property, there's no 'not low enough' >> problem. You apply a signal, you get the measurement. >> >> If there's a NONLINEAR property, like from boiling electrolyte, higher pulse >> currents might find it. Is that what you're after? > >Resistance, inductance and capacitance are concepts that we use to >describe what we see in the physical world. They apply very well to >some things (like a wire wound coil or a composition resistor), pretty >well to some things (capacitors for example) and not very well at all to >still others (semiconductors are good examples). Capacitors are not >described perfectly by a model using only resistance, capacitance and >inductance. There are non-linear effects caused by the material >involved doing things other than simply polarizing. That is why there >are different capacitor types, they are non-perfect in different ways. > >You know all of this. Why are you guys arguing over nothing? Aren't >there more productive things to discuss?
Introduce something interesting. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation