Author Topic: 5 Transistor ESR Meter Design  (Read 188272 times)

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Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #300 on: August 21, 2020, 05:47:50 pm »
measuring a 3r9 resistor
 

Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #301 on: August 21, 2020, 05:49:36 pm »
measuring a 1.1 ohm resistor
 

Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #302 on: August 21, 2020, 06:23:20 pm »
few pics of the guts of it.
 

Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #303 on: August 21, 2020, 06:27:22 pm »
final pic
 

Online bd139

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Re: 5 Transistor ESR Meter Design
« Reply #304 on: August 21, 2020, 06:58:10 pm »
Nice work. Also good use for those horrid Bradley meters  :-DD. Thumbs up here  :-+
 

Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #305 on: August 21, 2020, 09:15:35 pm »
thats what i thought,i brought 5 of those meters from j,birketts in lincoln for £5 a pop,absolute baskets to work on so gave up,handy for the meter movements tho.
 

Online bd139

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Re: 5 Transistor ESR Meter Design
« Reply #306 on: August 21, 2020, 09:18:32 pm »
Wow is he still around? I went in there probably 20 years ago now purely by accident after driving past and it looked interesting. Came out with a whole box of crap and an angry and hot girlfriend  :-DD
 

Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #307 on: August 22, 2020, 09:42:58 am »
Yes he is still going,i was in there chatting with him a few months ago,he is over 90yrs old now,still sharp as a needle tho,i was asking about collins 318t radios,said he had a load but brought them from the raf and sold them all to the army,interesting fella,just as deaf as a post!.
 
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Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #308 on: August 23, 2020, 06:34:52 pm »
just found a .1 ohm .5% resistor to measure,sort of taken back how well it reads such low values,the big meter scale makes it so easy to read,this ones a keeper!
 
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Offline bitseeker

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Re: 5 Transistor ESR Meter Design
« Reply #309 on: August 23, 2020, 07:34:56 pm »
And the "Lethal Warning" label adds a little extra something to it. ;D
I TEA.
 

Offline m3vuv

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Re: 5 Transistor ESR Meter Design
« Reply #310 on: August 29, 2020, 03:00:29 pm »
mr diddy,is there anyway i can run this from a pp3 9v battery,just less hassle than lithium ion batterys with the associated bms etc for charging,a single pp3 would be better,cheers m3vuv.
 

Offline rogerggbr

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Re: 5 Transistor ESR Meter Design
« Reply #311 on: October 23, 2020, 06:18:44 pm »
Just like to add my thanks to Jay_Diddy_B for the original design and all the posts above which helped. I used vero board, a spare box and bought a new meter. Just need to tidy up and label up properly but works really well at those low ranges. [attach=1][attach=2]
 
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Online Jay_Diddy_B

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Re: 5 Transistor ESR Meter Design
« Reply #312 on: October 23, 2020, 07:54:45 pm »
rogerggbr,

First of all welcome to the EEVBlog forum!!

and thank you for the kind words and sharing the pictures of the ESR meter that you built.

( I see from your profile that you are from West Yorkshire. I originate from South Yorkshire, but that was a long time ago).

Regards,
Jay_Diddy_B
 
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Offline battlecoder

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Re: 5 Transistor ESR Meter Design
« Reply #313 on: October 23, 2020, 08:50:55 pm »
Just like to add my thanks to Jay_Diddy_B for the original design and all the posts above which helped. I used vero board, a spare box and bought a new meter. Just need to tidy up and label up properly but works really well at those low ranges. [attach=1][attach=2]
I have to admit I like coming back to this thread to see the builds from the community, so thanks for sharing yours, @rogerggbr!

I *really* like this circuit. It's so elegantly simple, and works really well, so thanks again @Jay_Diddy_B for the awesome contribution. Even when I got an LCR meter (that can do ESR) after I built mine, I always check the result against your device.
 
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Offline zoltanh

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Re: 5 Transistor ESR Meter Design
« Reply #314 on: November 15, 2020, 11:49:58 am »
Hi,

Greetings from Romania. I built the ESR meter and I would say it is great. However, the microA of 50microA I have is a small one. I have another one of 250 microA and one of 500 microA, both with reasonable size. I built the 250 microA ESR and 1 mA ESR but both of them do not get out more than 150 microA. I checked everything, voltages, signals' levels and forms on oscilloscope and everything it seems to be in line with all available info herein.
Is here somebody who built any of these two variants, 250  microA or 1 mA ? If yes, could you share to me what level of current (maximum deflection) he obtained and eventually what components values he put it or any advice as I do not understand what is wrong with mine? I suspect something is wrong with amplification factor but could not figure out what or why.
I apologize for my ignorance and thank you for help.
 

Offline kripton2035

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Re: 5 Transistor ESR Meter Design
« Reply #315 on: November 15, 2020, 12:25:09 pm »
did you try the other variant of the esr meter, made by the same author.
see here : https://www.eevblog.com/forum/projects/esr-meter-adapter-design-and-construction/
it has the advantage of beeing more robust to charged capacitors, and to output to any voltmeter (or your multimeter)
so that you can use any voltmeter you want, analog or digital.

Offline zoltanh

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Re: 5 Transistor ESR Meter Design
« Reply #316 on: November 15, 2020, 06:37:05 pm »
Hi,

Thank you for reply.
I did not try it. I prepared the pcb and passive components. Unfortunately, I do not have the CIs. I am looking to find out a source at reasonable price for my budget.
However, I would like to finish the build of either 250 microA or 1 mA. Unfortunaley, I do not know what I miss or mistake there. Therefore, I am interested if somebody built any of them and what he can advise me about.
 

Online Jay_Diddy_B

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Re: 5 Transistor ESR Meter Design
« Reply #317 on: November 16, 2020, 11:57:50 am »
Hi,

Thank you for reply.
I did not try it. I prepared the pcb and passive components. Unfortunately, I do not have the CIs. I am looking to find out a source at reasonable price for my budget.
However, I would like to finish the build of either 250 microA or 1 mA. Unfortunaley, I do not know what I miss or mistake there. Therefore, I am interested if somebody built any of them and what he can advise me about.

Hi zoltanh and the group,


250uA

The discussion on using a 250uA meter starts at reply 227 here:

https://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/msg2456304/#msg2456304

I gave forum member Richard9026 the modifications that are required. He built a meter using these changes.

In reply 229 Richard9026 reported that these modifications worked.

1mA

There have been repeated requests for a version that uses a 1mA meter. This is not as easy to do. The current required is 20x the original design.

Link: https://www.eevblog.com/forum/projects/5-transistor-esr-meter-design/msg3008380/#msg3008380

In reply 265 I shared an LTspice that shows the modification required for a 1mA version. I have never built this version.
Forum member M3VUV built the 1mA version. In reply 289 M3VUV reported:

Hi all,ive just built the version of this using the 1ma meter movement,strange thing is with the test probes open it reads 3/4 scale to the right,when the test probes are shorted it goes fully to the left,any ideas?,cheers in advance.m3vuv.

In reply 298 M3VUV reported:

Well,ive sorted it,i lfted the ground of the regulator and added an led + a 1n5711 schottky diode between that and ground(shall use the led as an on indicator later)that lifted the 7805 output to about 7.1v,now the meter will go full scale,and i get 125 milivolt at the test probes so still good for in circuit testing,im running it from a 3s 3p lion 18650 battery pack thats 7.2 ah so should last a while on a charge,will upload some pics soon,it reads about %10 low but thats as near as dam it for me!,cheers jay 73 m3vuv.

In short, the 1mA circuit works if you increase the voltage from 5V to 7V.

I have not investigated this.

Regards,
Jay_Diddy_B

 
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Offline zoltanh

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Re: 5 Transistor ESR Meter Design
« Reply #318 on: November 16, 2020, 07:45:19 pm »
Hi,

Thank you very much for taking the time to reply to my messages.
I have read all the posts of this subject at least three times each, hoping that I missed something which to help me to figure out what is not ok.
As I said I succeeded to build and to get it works for 50 microA variant and up to 150 microA (actually, it was 147 microA) with both variants 250 microA and 1 mA schematics but I could not get higher deflection, amperage.
I tried also to increase the voltage supply. Sadly, I could not increase the output current value above mentioned level, and actually increasing the voltage supply above 7V decreased the deflection to around 110-104 microA.
I prepared other two THT PCBs and one smd PCB and my intention is to build one 250 microA THT, 1 mA THT and 1 mA SMD and see if I can get at least 250 microA. I pretty sure your simulations are fine and something is wrong with my PCBAs but I have no clue what it could be.
I would appreciate any advice as I do not have any idea what to check more and eventually what to experiment (I did not mention before that I did several trials with different values of resistors and capacitors in emitter/collector of Q3, Q4 and Q5 but w/o success).

Thank you.
 


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