Help troubleshooting homemade ESR meter

[ELItheICEman]

Ok, I built an ESR meter using the schematic and instructions here (I think it's fairly popular, maybe one of you guys have built this before?). I've went through the process of tracing all the components through the circuit and comparing to the schematic, All seems well. The problem most likely lies in my knowledge of transformers, I ordered the EA-77-188 Tiny double E core and the same gauge magnetic wire used in the guide (AWG #36 and AWG #26). On my first attempt I initially started winding the #36 wire perfectly around the bobbin, each loop adjacent to the last winding. That is until I realized it would probably take at least an hour to wind 400 turns like this. So I kind of sped up the process of winding while negatively affecting the uniformity and neatness. I finished up with some masking tape and started the next run (20 turns of #26 wire). Again I used masking tape to finish up. I then slid the E cores into place (although I didn't glue them in any way). I then put the transformer onto my circuit board and applied voltage to the circuit. The needle on the uA meter jumps ever so slightly upon turning on the circuit but nothing else. I've tried a few caps and resisters on the test leads and adjusted the trim pot in every position. I'm getting a steady 5V on the board, but I haven't really found many other helpful results from other test points. I have an oscilloscope but I'm not exactly fluent in using it...

[cmj21973]

Re: Help troubleshooting homemade ESR meter

1) When you say masking tape, do you mean paper painters tape or something else? hopeful you mean electrical tape.

2) Did you check to see if the two coils were isolated, meaning no continuity?

While the "E" cores don't need to be glued, they need to be wrapped with tape to hold them together

[budm]

Re: Help troubleshooting homemade ESR meter

Can you read continuity of both windings?

[Toasty]

Re: Help troubleshooting homemade ESR meter

Are C2 & C3 installed correctly?

- Neg of C2 to T1 // Pos to U1 Pin 1
- Neg of C3 to test lead/R6 junction // Pos to R7

You should also have 2.5v on U1 pins 3 & 5.


Toast

[cmj21973]

Re: Help troubleshooting homemade ESR meter

Can you read continuity of both windings?

Yes. You should have continuity on each coil, but you should not have continuity between the two coils.

If you have continuity between the two coils then the coils are shorting out to each other.

[budm]

Re: Help troubleshooting homemade ESR meter

The reason I ask if he can read continuity of each windings is to make sure he does remove the enamel coating off the wire before soldering.

[cmj21973]

Re: Help troubleshooting homemade ESR meter

Of coarse the best way to test the transformer is with a ring tester (FBT/LOPT)for high Q inductive components.

[budm]

Re: Help troubleshooting homemade ESR meter

Like this?
http://s807.photobucket.com/albums/y...0cap%20tester/

[cmj21973]

Re: Help troubleshooting homemade ESR meter

Yeah, that has a ring tester function.

The ring tester I'm reffering to is this one:
http://www.anatekcorp.com/bluert.htm

[ELItheICEman]

Re: Help troubleshooting homemade ESR meter

Ok, so I checked the caps and had to change one around, I didn't notice polarity was indicated in the schematic. I checked the voltages on the IC, pin 3 was around 2v and pin 5 was closer to 3v. I pulled the transformer off, the 2 coils are not connected shorted. When I check continuity on the 400 turn (#26) coil I get a high pitched tone from my meter instead of the normal beep and a reading of 19 ohms. I am going to *patiently* rebuild the transformer soon. Any tips on the actual making of the transformer? I couldn't find any help online. The first transformer I made I ripped the wire trying to sand off the enamel and had to start all over. Any help would be greatly appreciated, and I'm sorry it took me so long to get back to you guys!

[senz_90]

Re: Help troubleshooting homemade ESR meter

hello everybody. i need help to make my panel meter. i designed esr meter from this website
http://kakopa.com/ESR_meter/

and i think that's function. but i get problem with meter measurement. i try to fix my small vu meter with esr wizard i found on googling.

the problem is the panel meter didn't match the exact value with resistor i measure.. of course i think esr wizard don't have a same specifications with my esr meter. it was factory built of course with good quality

i just try anyway.

when i test 15 ohm resistor it just nearly 15 ohm on my meter. don't exactly pointed on 15 ohm . when i test with 10 ohm resistor it give me a same result as before i just try to modified value on that image with photoshop. but it didn't makes me satisfied enough.

so i think i need a software designing my panel meter. i try googling and got result Front Designer 3.0 but it just using Russian language. i didn't understand Russian language so the point is i want a software that could design panel meter easily and freeware of course.. hehehe.

please someone help me suggest a freeware software to design panel meter or if you don't mind u can send your software that u usually used for design panel meter to my email too.

i really want a professional looks on my esr meter.

[senz_90]

Re: Help troubleshooting homemade ESR meter

hmm.. i just think this is a good forums because it's likely discuss more about caps and repairment and the first thing i think crucial is ESR topic!!

But after one day, that's no one wanna go to reply instead help me.
yeah. it doesn't make me upset.. maybe i wanna go to another forums and try their helped !!

[Agent24]

Re: Help troubleshooting homemade ESR meter

You would probably get better results if you use a vector-based image editor like Inkscape or Illustrator

[ben7]

Re: Help troubleshooting homemade ESR meter

hello everybody. i need help to make my panel meter. i designed esr meter from this website
http://kakopa.com/ESR_meter/

and i think that's function. but i get problem with meter measurement. i try to fix my small vu meter with esr wizard i found on googling.

the problem is the panel meter didn't match the exact value with resistor i measure.. of course i think esr wizard don't have a same specifications with my esr meter. it was factory built of course with good quality

i just try anyway.

when i test 15 ohm resistor it just nearly 15 ohm on my meter. don't exactly pointed on 15 ohm . when i test with 10 ohm resistor it give me a same result as before i just try to modified value on that image with photoshop. but it didn't makes me satisfied enough.

so i think i need a software designing my panel meter. i try googling and got result Front Designer 3.0 but it just using Russian language. i didn't understand Russian language so the point is i want a software that could design panel meter easily and freeware of course.. hehehe.

please someone help me suggest a freeware software to design panel meter or if you don't mind u can send your software that u usually used for design panel meter to my email too.

i really want a professional looks on my esr meter.

The output on the meter is likely non-linear, I.E. at one end of the range the resistance values are closer to each other.

P.S. Have you tried adjusting the 1K ohm potentiometer yet?...

[senz_90]

Re: Help troubleshooting homemade ESR meter

You would probably get better results if you use a vector-based image editor like Inkscape or Illustrator

would u mind give me a link that i can download it? but hopefully it can free. maybe u think that im crazily man who is always wanna free software. but i just think i may using that software for a 3-4 times, not more. after my meter have been done. maybe i just lay it down on my computer

The output on the meter is likely non-linear, I.E. at one end of the range the resistance values are closer to each other.

P.S. Have you tried adjusting the 1K ohm potentiometer yet?...

\

yeah at one end of the range the resistance values are enough closer to each other. so what i must to do make it linear likes as other esr meter? i just want to make my meter can read even 0.xx resistance like this esr wizard meter

yes, i have tried to adjusting the potentiometer and the scale can deflect to 0 ohm on my vu meter (-3 values on vu meter)and the led is glow with probes lead shorted >>i think that my project is success and i have tried it measure any leaky caps between good caps.. i just try to fix esr wizard scale panel meter and the result is just like I said before on my post. it must to rescale again because it didn't match. i have ever read on another homemade esr meter link that it is always must to rescale with small value resistor. so i try to measure it and it didn't give me a satisfied result about the scale.

so i think the problem just make a new scale looks profesional that describe the value same as when i measuring small value resistor. i have edited before with photoshop but you know what i means. it didn't present any real scale. just present 1-30 ohm resistor, for notes i just measure and the max scale that i can measure is 30 ohm and it almost not a deflection (little deflection) on my left panel meter. so i means that it can't present when we want measure different between 0.22 ohm and 0.33 ohm value.. maybe the esr meter doesn't success yet?? or i just have to make a new panel meter to fix on my vu meter?

my vu meter looks like this

[ben7]

Re: Help troubleshooting homemade ESR meter

between 0.22 ohm and 0.33 ohm value.. maybe the esr meter doesn't success yet?? or i just have to make a new panel meter to fix on my vu meter?

my vu meter looks like this

As stated in the article (although not tested by the writer), try changing R14 and R15 to 47K. Then, change the resistors R10 and R11 to, say, 10 ohms.

The difference is fed to op-amp C which amplifies it. The feedback resistors in the original were 47K but this led to a certain problem which was solved by lowering the gain by lowering the value of the resistors to 27 K. After building my prototype I am thinking that it may have been better to leave the 47 K resistors and lower the value of the two lower resistors of the bridge from 22 ohm to 15 ohm or even 12. That would make the instrument more sensitive to lower ESRs. I may try that in the future.

[Agent24]

Re: Help troubleshooting homemade ESR meter

would u mind give me a link that i can download it? but hopefully it can free. maybe u think that im crazily man who is always wanna free software. but i just think i may using that software for a 3-4 times, not more. after my meter have been done. maybe i just lay it down on my computer

http://inkscape.org/download/?lang=en

[senz_90]

Re: Help troubleshooting homemade ESR meter

As stated in the article (although not tested by the writer), try changing R14 and R15 to 47K. Then, change the resistors R10 and R11 to, say, 10 ohms.

i haved makes changed already. i use R10 and R11 15 ohm
and R14, R15 47k. because when i hadn't make changed, my meter couldn't deflect to 0 ohm scale. after did it my scale looks normal.

the problem is just likes what you said. maybe it's not linear.. but I haved try to measure any bad caps that i haved and it function where is the one bad caps i tested don't make my meter deflect. and the others didn't have a small ESR. it looks like more than 3-4 ohm with high capacitance caps likes 470 microfarad. btw it not a bad result of course. i think this esr meter is so useful. now i wanna go to download any software to try to fix my panel meter..
i just compare with other new caps and it makes different whereis the new caps have a very low ESR near 0 ohm on my meter..so it is worth to build homemade esr without many feautures. but i think this is useful for a colleger likes me with a little of money because don't have works yet..
anyway thank you for your advice sir

http://inkscape.org/download/?lang=en

thanks sir for your help. i am newbie on electronic. but i'll try my best with a useful equipment to be a good technician..