secret life of capacitors copy

8/9/2019 Secret Life of Capacitors Copy

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The Secret Life of Capacitors

This collection of some rarely mentioned characteristics of the capacitor was inspired by anaccount of some capacitor voltage readings collected around 2001 by a fellow contributor tothe overunity.com website a certain 'Nerzh ishual'!!

"t was also #r 'ishual' $N% who suggested this title so i thin& it would be appropriate todedicate this informal report to him

couple of years ago N mentioned that he'd ta&en some long(term voltage measurementson a capacitor and he was interested that it could show a 'spontaneous' fluctuating voltage

Isn't this just 'Dielectric Adsorption'?

The term 'ielectric dsorption' is usually applied to theoff-load

self(recharging effect seenon some capacitors after being discharged by a load

This collection of information is mainly involved with the 'spontaneous' charge and thendischarge of voltage on a capacitor which is still on-load$albeit high(impedance%

"n any case) *ust giving something a label $eg. 'ielectric dsorption'% isn't the same asunderstanding more about what is involved in an effect

Just how long a 'memory' is Dielectric Adsorption supposed to hae?

The following graph shows a 'spontaneous' voltage increase on a +,00u- capacitor $enclosedin an aluminium case% the capacitor was previously shunted by a 1 #ohm resistor for appro/., months and then on 1 an 2010 the shunt was shorted and then removed

!ig "# 'spontaneous' oltage on capacitor s# days since "$ohm shunt remoed


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"n the few months since the shunt was removed) the 'spontaneous' voltage has increased to afew hundred millivolts

hat was happening to the capacitor for several months before the shunt was applied3 "twas undergoing the datalogging tests) where the voltage was in the range 0 10m4 ma/ formany months so ielectric dsorption cannot e/plain the spontaneous 'regeneration' of

several hundred millivolts when the previous voltage history was *ust millivolts

There is something 'going on' with capacitors that the unhelpful label 'ielectric dsorption'does not begin to e/plain5

6o the first 7uestion about what might be involved in generating this 'spontaneous' voltageeffect is this8

Could a familiar enironmental condition %e inoled this effect?

9ere is N's graph of capacitor voltage readings ta&en in :ctober '018

!ig#& m charge on capacitor s# day of month

The first thing to notice is that there is obviously a daily variation in the voltage

" did a web search for various environmental data collected in the same geographic area forthe same period8

!ig# ( )ressure s# day of month


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!ig# * +um%er of Sunshine hours s# day of month

!ig# , $in# temperature s# day of month

!ig# - $a.# temperature s# day of month

"t appeared that the closest correlation to the spontaneous voltage on the capacitor was givenby the temperature readings

" combined the separate data for ma/imum ; minimum temperatures for the month of :ct '01

and this gave the following 'match' to N's data you can compare his measurements andthe combined min. ma/. temperature readings below8(


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!ig# / com%ined min# 0 ma.# local temperature readings 12ct '3"4

!ig# 5 +D's data for 'spontaneous' oltage on a capacitor 1 2ct# '3"4

6o the answer to this 7uestion is 'yes) there does appear to be a reasonably close correlationbetween the local temperature and the 'spontaneous' voltage on the loaded capacitor'

Isn't a capacitor under resistie load supposed to follow an e.ponentialdischarge rate?


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"'ve observed occasions when the voltage on a capacitor under light load has actuallyincreased for a while before continuing with the usual 'e/ponential' discharge trend

"f we zoom in on the discharge data at the ringed position on the graph below8

!ig# 6 Capacitor discharge oltage under load

we find this8

!ig# "3 detail of capacitor discharge oltage under load

-irst of all) we can clearly see the 'step' nature of the capacitor discharge waveform forappro/. 20 minute sections the slope of the voltage discharge is almost horizontal) beforecontinuing its downward trend

nother interesting feature of the 'horizontal step' section is that the voltage slope appearsrelatively 'smooth' whereas in the steeper slope sections there is a significant increase offluctuations


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There are several instances where the voltage on the loaded capacitors are actually rising forat least ?0 seconds two e/amples above are shown ringed ( the capacitors obviously don'trealise that this is in direct violation of the so(called '2nd=aw' of thermodynamics and that whatthey are doing is supposedly 7uite impossible5 $in some people's view%

Does this 'step' function occur elsewhere?

@ompare the voltage 'step' characteristic below) on a discharging capacitor8

!ig ""# oltage 'step' function of capacitor discharge under load

with result data shown below from 2 Ni#h batteries discharging under loads8

!ig " oltage 'step' function of +i$7 %attery discharge under load

n interesting similarity of behaviour

The voltage levels of each 'step' appear to be fi/ed for each capacitor or battery the samelevels of step voltage appear when charging or discharging $cf. pril 1+ graph in the ppendi/data% ( so it is a physical characteristic of that component

re we observing the macro effect of some Auantum operation in releasing ; storing energywhich is common to capacitors and batteries3

The load doesn't change in either of these cases so at the micro level) capacitors andbatteries can have two different rates of converting energy) not one

This suggests that the energy conversion process has two distinct phases or type of function


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hat we see at the macro level is only an appro/imation of these different phases orfunctions an 'averaging' of the two rates

7ow were the result data listed %elow o%tained?

+,00u- electrolytic capacitor was shunted with a 1#ohm 0. carbon resistor and

enclosed in an aluminium case

!ig# "( a4 0 %4 side 0 top iews of test capacitor 88 magnet arrangement

several Neo magnets were fi/ed around the capacitor) parallel to the can) all with the samepole pointing towards the top of the capacitor this created a magnetic field within thecapacitor which was at right(angles to the voltage field across the internal spiral arrangementof the capacitor 'plates'

The graphical results in the ppendi/ below were obtained using a B@ datalogger to ta&e avoltage reading every 1s

The initial voltage on the capacitor was allowed to discharge by means of the shunt resistor

hen the voltage had discharged to somewhere in the region of a millivolt it started toincrease again and the 'spontaneous' voltage profile started to appear) as shown in theppendi/ data $the p&(p& voltage was only a few m4 dependent on the shunt resistance%

Is there a general pattern of the daily fluctuation?

-irst of all) we have to ignore the 'step' function which we've already seen is common tocapacitors and batteries this is an artifact of general capacitor behaviour $regardless of whatmethod is used to charge>discharge it%) it's not related to the cause of the 'spontaneous'voltage


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The voltage profile changes each day) sometimes slightly) sometimes e/tensively) but thereare some recognisable pattern groups

The most common feature is a voltage minima at appro/. 0+800 0C800 DT@

There are pea&s around 10800) 20800 and 00800 DT@ which occur fairly often in the results

!ig# "* %asic daily pattern of 'spontaneous' oltage profileon shunted stand9alone capacitor

Is the capacitor influenced %y magnetic field?

6ome Neo magnets were arranged around the circumference of the the capacitor under testthe magnets were arranged with li&e poles facing up towards the top of the can) ie) theresulting magnetic field within the capacitor was parallel to the capacitor can and at rightangles to the voltage gradient across the internal spiral arrangement of the capacitor 'plates'

!ig# ", influence of static magnetic field on 'spontaneous' oltage of capacitor

The sections of the waveform mar&ed with red e/tent lines show that the 'spontaneous'voltage on the capacitor e/hibited an increase when a magnetic field was induced within thecapacitor

Does the 'spontaneous' oltage occur inside a '!araday cage'?

The test arrangement was moved into a microwave oven $which was powered off obviously)but still grounded%atalog readings of the 'spontaneous' voltage were recorded for a few minutes then the probe

was disconnected for a few minutes with the #: door closed


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"f we loo& at the graphs for pril 2E ; 2th200F around midday when the moon wasappro/imately in line between the DG longitude and the sun) the voltage profiles for the twodays are very different which suggests that the main driver for the fluctuation of the'spontaneous' voltage is not a gravity effect of the moon northe position of the moonobstructing solar emissions to the earth

7as there %een any other influence seen on the capacitor?

Tesla mentioned a relationship between capacitance and altitude i don't have any definiteindication of this in these results) but on several occasions when the capacitor under test wasmoved between different floors of buildings there was a noticeable change in the @ levels ofthe voltage waveform

>hat's the erdict?

:bviously) local temperature has an important influence on the voltage

could there be any other contributory factors3

i found data for another naturally occurring phenomenon which appears to produce aremar&ably similar profile to the voltage fluctuations on a shunted capacitor

here is some data from a completely different source8

!ig# &3 a 'oltage' profile caused %y solar emissions

"t's not the 'spontaneous' voltage on a electronic component capacitor it's an e/ample of'spontaneous' voltage on the planet Harth's capacitor

the graph in -ig 20 shows some sample data for the ma/imum free electron density in the '-(region' of the ionosphere recorded above one particular location by ionosonde $the detail willvary to some e/tent) according to latitude of the sampling location%


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!ig# && >inter +m!& scan

-ig. 22 is a 2E hr global scan of the -2 ionospheric electron density the data in -ig. 20above represents a horizontal cross(section $ie. at a single =atitude% of the global scan

s the earth revolves beneath the ionosphere $which is getting charged by the solar wind% theionosonde data provides an electron density profile for a 'latitude' strip across the chargedarea

!ig# &" sample 'spontaneous' oltage profile from a capacitor 1"/ Apr '364

so my interpretation $at present% of what is happening in a small scale on our electroniccapacitors is that the main factor is the ambient temperature around the capacitor and anadditional factor could be due to the atmospheric charge in the ionosphere or to theparticles which cause it

sandy r*thJuly &3"3 1reised (rdApril &3""4http=88docsfeelunch#%logspot#com

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!! i understand that the phrase 'Nerzh ishual' in the

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