Author Topic: 5 Transistor ESR Meter Design  (Read 129141 times)

0 Members and 4 Guests are viewing this topic.

Offline Jay_Diddy_B

  • Super Contributor
  • ***
  • Posts: 1667
  • Country: ca
Re: 5 Transistor ESR Meter Design
« Reply #50 on: November 15, 2013, 12:56:42 pm »
BravoV and the group,

R18 represents the analog meter. So the current in R18 is proportional to the meter deflection. The simulation does not include the zero pot. The zero pot would be used to set the meter current to 1mA with a short on the input.

Jay_Diddy_B
 

Online BravoV

  • Super Contributor
  • ***
  • Posts: 5245
  • Country: id
Re: 5 Transistor ESR Meter Design
« Reply #51 on: November 15, 2013, 01:19:26 pm »
Thanks, now I'm writing this into my notebook, in spice simulation ... resistor = analog meter.  :-+
 

Offline AndersAnd

  • Frequent Contributor
  • **
  • Posts: 568
  • Country: dk
Re: 5 Transistor ESR Meter Design
« Reply #52 on: November 15, 2013, 07:56:31 pm »
Off topic, in above simulation, which parts represent the analog meter ?
R18

You can find info about VK5JST's ESR meter here http://www.users.on.net/~endsodds/esr.htm

Direct link to the PDF schematic: http://www.users.on.net/~endsodds/ESRCircuit.pdf
 

Offline dannyf

  • Super Contributor
  • ***
  • Posts: 8229
  • Country: 00
Re: 5 Transistor ESR Meter Design
« Reply #53 on: November 15, 2013, 11:19:57 pm »
You could change the last stage slightly so the output is a voltage signal - good for both analog and digital multi-meters.
================================
https://dannyelectronics.wordpress.com/
 

Offline Jay_Diddy_B

  • Super Contributor
  • ***
  • Posts: 1667
  • Country: ca
Re: 5 Transistor ESR Meter Design
« Reply #54 on: November 16, 2013, 12:14:23 am »
DannyF and the group,

To answer your question.

Nearly all of the ESR meters designed for analog meters have a non-linear response. My 5 transistor ESR meter at the start of the thread had a response like this:



This results in a meter scale like this:



This non-linear scale is  actually desirable on an analog meter, because it expands the lower value readings over a large section of the meter scale.

The digital meters require an output which is linear and proportional to the ESR.





It would be quite challenging to take the non-linear output from an analog style ESR meter and convert it into a linear scale for a digital meter.

So there are really two kinds of ESR meter circuits.

I hope that this answers your question.

Jay_Diddy_B
 

Offline dannyf

  • Super Contributor
  • ***
  • Posts: 8229
  • Country: 00
Re: 5 Transistor ESR Meter Design
« Reply #55 on: November 16, 2013, 12:31:37 am »
Quote
a non-linear response.

It is not about linearity. It is about having a current output vs. a voltage output.
================================
https://dannyelectronics.wordpress.com/
 

Online BravoV

  • Super Contributor
  • ***
  • Posts: 5245
  • Country: id
Re: 5 Transistor ESR Meter Design
« Reply #56 on: November 16, 2013, 02:10:55 am »
You could change the last stage slightly so the output is a voltage signal - good for both analog and digital multi-meters.

Post how and the circuit, please.

Hope it will not be too complicated to build or need exotic hard to find components.
 

Offline Jay_Diddy_B

  • Super Contributor
  • ***
  • Posts: 1667
  • Country: ca
Re: 5 Transistor ESR Meter Design
« Reply #57 on: January 01, 2014, 04:41:48 am »
Hi group,

 A couple of people have asked me to clarify the connections to the potentiometer and the meter. So here is a revised schematic that shows these connections:




Jay_Diddy_B
 

Offline cellularmitosis

  • Supporter
  • ****
  • Posts: 1029
  • Country: us
Re: 5 Transistor ESR Meter Design
« Reply #58 on: January 01, 2014, 08:30:23 am »
What a cool project!

Not to hijack the thread, but I wanted to mention that a while back I whipped up a quick python script for generating analog gauge faces like that:

http://jason.pepas.com/wiki/index.php?title=AsiaEngineerGauges

http://jason.pepas.com/wiki/images/5/58/Asiaengineer-0.5-signorm.png

I suppose I should put it up on github!


LTZs: KX FX MX CX PX Frank A9 QX
 

Offline koogar

  • Contributor
  • Posts: 15
  • Country: gb
    • Runaway Brainz Tech and Tinker Blog
Re: 5 Transistor ESR Meter Design
« Reply #59 on: March 18, 2014, 02:16:01 am »
Hi group,

Has anybody else built this ESR?

Would there be any interest in a thru-hole circuit board design?

Regards,


Jay_Diddy_B

Hi Guys

I have designed a through hole version of the 5 transistor ESR off  Jay's  schematic below




What could I substitute for the ES1J SMD diodes,  D1 & D2 in through hole ?
Also what are the common alternatives for D3 & D4 ?

I will post all the files after I have updated the Schematic and PCB layout.

Cheers

Rupert
« Last Edit: March 18, 2014, 02:18:47 am by koogar »
 

Online BravoV

  • Super Contributor
  • ***
  • Posts: 5245
  • Country: id
Re: 5 Transistor ESR Meter Design
« Reply #60 on: March 18, 2014, 06:59:00 am »
does it make sense to couple a sub circuit that "eats" this signal and "anti-logs" it (or log it?)? so that it spews something linear?
Like this ?  ;)

Click -> ESR Meter Adapter Design and Construction , came from same designer as this one by our great contributor Jay_Diddy_B.  :clap:
 

Offline koogar

  • Contributor
  • Posts: 15
  • Country: gb
    • Runaway Brainz Tech and Tinker Blog
Re: 5 Transistor ESR Meter Design
« Reply #61 on: March 18, 2014, 09:16:02 am »
Hey Guys

Here are the PCB files for a through hole version .






Eagle PCB Files Attached

Cheers

Rupert
« Last Edit: April 06, 2014, 01:20:28 am by koogar »
 

Offline Jay_Diddy_B

  • Super Contributor
  • ***
  • Posts: 1667
  • Country: ca
Re: 5 Transistor ESR Meter Design
« Reply #62 on: March 18, 2014, 09:46:15 am »
Hi,

Rupert,
That is a great job you have done with the design, converting it to thru-hole  :clap:


The ES1J diodes can be replaced by 1N4001, 1N4002 etc or 1N4935. These diodes take a beating if you connect a charged capacitor to the terminals.

D3 and D4 are critical, the 1N5711 will be fine. You need low capacitance small-signal Schotky diodes.


You want a panel mounted potentiometer for R23. You have to zero the meter to adjust for the lead resistance.

How are you going to make the board?

I will be happy to answer any questions that you might have.

Good luck !!

Jay_Diddy_B

 

Offline koogar

  • Contributor
  • Posts: 15
  • Country: gb
    • Runaway Brainz Tech and Tinker Blog
Re: 5 Transistor ESR Meter Design
« Reply #63 on: March 18, 2014, 10:30:05 am »
Thanks for the advice and feedback Jay :)

The pot was only really on the PCB for testing  purposes.

what value would you suggest for R24 in series with the meter ?

All my panel meters seem to be 100uA,  what modifications do you suggest to drive it full scale ?
I will be etching the PCB.

PS. thanks for sharing your design, I will keep the thread updated

Thanks

Rupert


« Last Edit: March 18, 2014, 10:34:04 am by koogar »
 

Offline Jay_Diddy_B

  • Super Contributor
  • ***
  • Posts: 1667
  • Country: ca
Re: 5 Transistor ESR Meter Design
« Reply #64 on: March 18, 2014, 11:47:43 pm »
Rupert and the group,

If you have a 100uA meter, the total resistance, meter + resistor plus + (pot resistance / 2) should be equal to about 7.5 k Ohms.

Jay_Diddy_B

 

Offline 1jonnyz

  • Contributor
  • Posts: 25
  • Country: us
Re: 5 Transistor ESR Meter Design
« Reply #65 on: March 19, 2014, 12:17:53 am »
I wonder how difficult would this be to build on a stripboard?  It seems like I would run out of room, given the size of my box, which is 6" x 3 1/2".
 

Offline zaoka

  • Frequent Contributor
  • **
  • Posts: 374
  • Country: us
Re: 5 Transistor ESR Meter Design
« Reply #66 on: March 19, 2014, 12:50:13 am »
So what do I modify to increase the range of up to 50ohm without loosing 20% of the scale for 0-1 range?
  :-//

Also to use 1mA meter.

Plsss :)
 

Offline Jay_Diddy_B

  • Super Contributor
  • ***
  • Posts: 1667
  • Country: ca
Re: 5 Transistor ESR Meter Design
« Reply #67 on: March 19, 2014, 02:23:30 am »
Hi group,

The deflection of the meter versus ESR comes from the properties of the unbalanced bridge circuit used in the design. You can adjust the resistor values in the lower legs of the bridge to bend the meter response.

This is an LTspice model that illustrates the effect of changing the resistor value. I have normalized the models to show 0-100% deflection.



These are the results for 1,3 and 10 Ohms:



3 Ohms was chosen the design to give the best scale on the meter, for the majority of applications.

Most electrolytic capacitors have an ESR less than 20 Ohms, if they are good.

Note: this model does not include the non-linearity introduced by the 1N5711 diodes.

It is not easy to adapt the circuit for a 1mA meter.



Jay_Diddy_B
 

Offline jim17

  • Newbie
  • Posts: 3
Re: 5 Transistor ESR Meter Design
« Reply #68 on: March 19, 2014, 03:18:45 am »
Hi Jay_Diddy_B,

I'm trying to simulate your circuit trhough ltspice, how do you do the plot ESR vs voltage ?


Thanks.
 

Offline zaoka

  • Frequent Contributor
  • **
  • Posts: 374
  • Country: us
Re: 5 Transistor ESR Meter Design
« Reply #69 on: March 19, 2014, 04:13:11 am »

Most electrolytic capacitors have an ESR less than 20 Ohms, if they are good.



If you test capacitors lower than 10uF range higher than 20R is needed, at least according to Sencore ESR troubleshooting sheet with min-max ESR values.
 

Offline Jay_Diddy_B

  • Super Contributor
  • ***
  • Posts: 1667
  • Country: ca
Re: 5 Transistor ESR Meter Design
« Reply #70 on: March 19, 2014, 07:06:36 am »
Hi,

Jim17 asked:

Hi Jay_Diddy_B,

I'm trying to simulate your circuit trhough ltspice, how do you do the plot ESR vs voltage ?


Thanks.

To obtain the graph.

Run the LTspice file. The circuit will run 15 times.
This from this SPICE Directive:

.step param R LIST 0.0001 0.1 0.2 0.5 1 2 4 6 8 10 12 14 16 18 20

When the analysis is finished from the VIEW menu 'Spice Error Log'

Then right click in the Error log window.

Click plot .step'ed .meas data

The curve will then be displayed.

Regards,

Jay_Diddy_B
 

Offline jim17

  • Newbie
  • Posts: 3
Re: 5 Transistor ESR Meter Design
« Reply #71 on: March 20, 2014, 01:15:05 am »
Hi Jay_Diddy_B,

Thanks for the response, I've done the steps and it worked !

Watching the different circuits you've done, I realise LTspice is a powerful tool to design analog circuits.

Keep the great job in this forum !
 

Online BravoV

  • Super Contributor
  • ***
  • Posts: 5245
  • Country: id
Re: 5 Transistor ESR Meter Design
« Reply #72 on: March 20, 2014, 01:21:31 am »
His LTSpice kungfu is probably one of the best around here.  :box:
 

Offline 3roomlab

  • Frequent Contributor
  • **
  • Posts: 774
  • Country: 00
  • A long long time ago, in a land far far away ...
Re: 5 Transistor ESR Meter Design
« Reply #73 on: March 23, 2014, 09:58:17 am »
does it make sense to couple a sub circuit that "eats" this signal and "anti-logs" it (or log it?)? so that it spews something linear?
Like this ?  ;)

Click -> ESR Meter Adapter Design and Construction , came from same designer as this one by our great contributor Jay_Diddy_B.  :clap:

ah yes  :-+

i can understand that a charge is generated (oscillator), dumped into DUT, then it gets picked up and measured. but specifically, i dont understand how do you know 1ohm is really 1 ohm ESR. in theory i can understand the reactance calculation, but in most ESR meters am i right to say, the correct way is to measure its potential after it gets a "known" test charge? or there is more theory i am missing?

i try to simulate it here http://www.eevblog.com/forum/beginners/esr-frontend   |O :-DD ... did i just confuse myself?
[What Do You Care What Other People Think?] ... remember to brush your teeth before you read it ... *tchk tchk tchk* ...
 

Offline w2aew

  • Super Contributor
  • ***
  • Posts: 1714
  • Country: us
  • I usTa cuDnt speL enjinere, noW I aR wuN
    • My YouTube Channel
Re: 5 Transistor ESR Meter Design
« Reply #74 on: March 23, 2014, 11:41:50 am »
does it make sense to couple a sub circuit that "eats" this signal and "anti-logs" it (or log it?)? so that it spews something linear?
Like this ?  ;)

Click -> ESR Meter Adapter Design and Construction , came from same designer as this one by our great contributor Jay_Diddy_B.  :clap:

ah yes  :-+

i can understand that a charge is generated (oscillator), dumped into DUT, then it gets picked up and measured. but specifically, i dont understand how do you know 1ohm is really 1 ohm ESR. in theory i can understand the reactance calculation, but in most ESR meters am i right to say, the correct way is to measure its potential after it gets a "known" test charge? or there is more theory i am missing?

i try to simulate it here http://www.eevblog.com/forum/beginners/esr-frontend   |O :-DD ... did i just confuse myself?

The principle with most ESR meters like this is to apply a test signal at a frequency that is high enough for the capacitive reactance to be well under 1 ohm. Thus, any voltage appearing across the capacitor is due to the ESR alone.
======================================
YouTube channel: http://www.youtube.com/w2aew
FAE for Tektronix
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf