How did your device work for you? Did you look at a "low ESR" capacitor versus a "regular" one? Love the build in a Levi's box!

hmm.. it looks like i wanna fix my components.. i feel there is something wrong, it is because i measure a failure capasitor and it still have a low ESR but the scale isn't reach 0 ohm. but it looks like 2-3 ohm... the meter i using is from googling and print to fix in small vu meter...

i just feel there is component doesn't match because leaking capasitor have a low esr too.. hmmm

is that means unexperienced of me or sometimes leaking capasitor maybe have a low ESR too?? please explain..

 

typI wrote:

I will try both a CFL transformer and camera transformer to see if they might work. It may a few days before I have results.

The Mouser transformer measures about a 30 to 1 voltage ratio from all of the primary to 1/2 of the secondary.
My calculations say it should be more like half of that -- I can't explain the mismatch.

I measured the resistances of the primary and secondary:
The DC resistance of the primary is 78 ohms and the secondary DC resistance is about 1 ohm.


The transformer in the CFL I took apart is a small toroid. Not at all suitale for the ESR meter.
What I had thought was a transformer is actually an inductor.


The transformer from the disposable camera shows more promise. It has a voltage ratio of about 350 to 1.
The frequency responce is up to greater than 60 KHz.

I measured the DC resistances of the primary and secondary:
The resistance of the primary is 380 ohms and the secondary resistance is 0.025 ohms.

The secondary is about 25 gauge (0.018" diameter) wire.

The problem here is the output voltage on the primary if the secondary is accidently connected to a charged cap.
The voltage could be hundreds of volts! Because of this, the over-voltage protection of the LM358 out and input needs to be improved by adding clamp diodes.
One way would be to put a series pair of 3.3 volt Zener diodes across the transformer primary.
Another way would be to clamp of the input and output pins of the LM358 with 1N4148 diodes to power and ground.

 

I only built one, referenced earlier in this thread. It seemed to be somewhat useful but was at least as much an inductance meter as an ESR meter.

I measured the inductance of a 25 uf, 25 volt electrolytic cap. I saw no inductive effects.

A 3300 uF, 25 volt electrolytic cap and again found no measurable inductance.

Not being able to measure any inductance does not surprise me. The way an electrolytic cap is made will tend to minimize inductance.

First, it is an air core inductor. Second, even though the capacitor is wound somewhat like a coil, the inductance is not great because the currents of the two capacitor plates flow in opposite directions thus cancelling out any magnetic field.

I believe you could use it to compare two capacitors side by side if care was taken to minimize any differences in the measurement other than swapping the capacitor.

Keep in mind that a simple ESR tester like the one I did is is really an impedance tester. It measures the impedance of a capacitor in series with the internal equivalent resistance.

At a frequency of 16 KHz, a 1 uF capacitor has a reactance of 10 ohms. This is likely to be larger than the ESR.

 

ohh.. thank you very much sir.. i'll try that design early...

Here is a link to a video that I did last year showing the design of a simple ESR meter that built several years ago:
http://www.youtube.com/watch?v=bmYAgat-sOQ

 

after a little effort i'm makes a change to connect pin 9 to pin 10 with a single resistor and i got satisfied with the result.. i find that way searching a same schematic from googling that use IC TL084..

the resistor that used is 47k ohm..

my vu meter scale deflect (so close) to 15 ohm when i tested with 15 ohm resistor. it's also can deflect to 0 ohm on meter. but it comes another problem that my meter isn't show the real value with resistor that i tested (u can know that i means so close but not exactly). any suggest software to make that panel meter looks professional? but i really want a free one software. or maybe you can send me software that you are using now for design front panel project?

im searching and got no result. i really likes software like FrontDesigner 3.0, but it looks like didn't freeware.

now the problem just to measure my panel meter with a low values resistor and print to fixing on my vu meter.

Please i need your help
Sorry for my bad english sir.

 

im searching and got no result. i really likes software like FrontDesigner 3.0, but it looks like didn't freeware.

You should be able to find a drawing program that will do what you want. I have not used it but OpenOffice has the ability to do drawings. It is free but the size of the download is huge.

Sorry for my bad english sir.

No need to apologize. I am quite sure that your English is much, much better than my use of your language no matter what it is.

​

 

You should be able to find a drawing program that will do what you want. I have not used it but OpenOffice has the ability to do drawings. It is free but the size of the download is huge.

No need to apologize. I am quite sure that your English is much, much better than my use of your language no matter what it is.

​

thanks for your forgiveness about my english..
i forgot to upload the esr wizard panel meter that i try to match on my vu panel meter. here is the meter panel that i found on googling. i dont intend to commercial this project design with that panel meter of course. it's just for myself and i think that's not problem to copy on my vu meter.

u can see explain that my problem on that pict of course. but maybe for now i satisfied enough to use that panel meter after modify it with photoshop.

open office same as microsoft office? it looks funny i ask this question but i don't expert on software ^^

if you have a good software to design panel meter or front panel project i really want it anyway. hahaha..

any idea to modify voltmeter into ammeter with picture explanation please? or make the voltmeter more "sensitive enough". I means that my voltmeter is for measuring AC electric. it can be enough measure DC too but what is the problem? the scale is 0 - 250 volt. u can imagine that scale couldn't show different between 3v- 5volt for detail.. it just deflect a little of needle.

same like this picture

 

if you have a good software to design panel meter or front panel project i really want it anyway.

I've been using Intaglio lately, which if free but Mac-only. Inkscape is a more full-featured open source option and runs on "everything", I believe. My all-time favorite was Freehand. Adobe bought and killed it buy you can still find bootleg copies out there. (I guess that applies to anything.)

My advice is to choose a vector drawing program as opposed to a painting app. Like Illustrator versus Photoshop. You can get good results either way but if you're starting off at zero, you'll be happier with a vector drawing program. The principle advantage is that everything is scalable and resolution-independent. No pixels until the final output.

 

I've been using Intaglio lately, which if free but Mac-only. Inkscape is a more full-featured open source option and runs on "everything", I believe. My all-time favorite was Freehand. Adobe bought and killed it buy you can still find bootleg copies out there. (I guess that applies to anything.)

My advice is to choose a vector drawing program as opposed to a painting app. Like Illustrator versus Photoshop. You can get good results either way but if you're starting off at zero, you'll be happier with a vector drawing program. The principle advantage is that everything is scalable and resolution-independent. No pixels until the final output.

vector drawing program !! that's i mean needed for serious.. yeah i just starting off at zero and try my best to be a good electrician.
resolution independent and scalable... would u mind give me information where i can download the program? or any website maybe sir? as mention i haved try photoshop before. but it couldn't make a really scale because i just modified it but the scale is very disgusting i thought. because it doesn't present a real scale.. just any modified number to match on my esr meter with small value resistor..