Cheaper ESR meter

[whiz]

Re: Cheaper ESR meter

www.elfa.se offers the same service, I guess you should choose the one which offers to build the least number of PCB'S

I don't think it's a big problem...we can all together decide it...

The problem is the designing and the organizing! i could organize it but i haven't organized group buy up to now

if someone knows how to create PCB layouts...etc and there is more interest about the ESR meter i think we can somehow....proceed....

i just hope gs3 is willing to support us...

anyone knows Eagle or some other designing program and wishes to help?

I suggest a few people build some prototypes and, after they test them they report their findings and any suggestions for improvements.

yes...i agree we must build some prototypes fist...and maybe improve them...with your help!

[arneson]

Re: Cheaper ESR meter

gs3,
I imagine you have spent a lot of effort so I'll throw this out to anyone.
I have the Heathkit experimenter series breadboard set.
I am out of this now and they are unused in junk box, somewhere under garage pile.
It makes designing circuits way easy. Plug and play with power.
Someone could put this to good use and make this ESR circuit.
I could certainly use one, built as large probe would be nice.

[gs3]

Re: Cheaper ESR meter

Well, if anyone wants to put together a prototype, I will be glad to help with any troubleshooting. I don't think I can do much more.

If you are going to tinker, it helps greatly if you have a 'scope so you can see what's going on.

I am going to see if I can get my friend to make some more PCBs for me but he does it as a fav9or and I do not want to abuse him.

[arneson]

Proto board

This proto board works well with any dip.
Circuit transfers directly from the bread board and solders with very few jumpers.
Using these was fun up to a point and became an obsession for years.
It's very convenient to dremel these to any shape you require, just tighten everything up and remove excess board.

[duldog]

Re: Cheaper ESR meter

good day everyone!

much to my regret, i've built this circuit even before i was able to read this thread.

anyway, is the circuit posted in the first page makes the meter read lower esr value better? the circuit i built reads about 1ohm at 95% deflection and about 50% deflection at 33 ohms.

[duldog]

Re: Cheaper ESR meter

Just an update:

i modified my previously-built circuit so that it now looks like the circuit presented in the first page. Now my problem is that it can no longer drive my 250uA meter to its full scale deflection. However, i can live with this setup and just calibrate the scale to suit my needs but it would be nicer with a full scale deflection.

[repairs online]

Re: Cheaper ESR meter

Hello,

Well duldog, there must be something wrong with your meter. I have not build the meter you are talking about (if someone could send me JUST the board, would greatly appreciated it), for a good cap over 10 microF, the ESR should be <= 1 Ohm. For a bad cap over 2 Ohm, lets say 3 Ohm.

33 ohms, as you say, is about at 50% deflection, therefore, for your meter to indicate 3 Ohm, the needle would have to be very close to where the reading for a good cap would read, making it very difficult to decide if it is a good cap or a bad cap.

Sincerely

[arneson]

Re: Cheaper ESR meter

If any one is beginning to consider circuit design I offer this experimenter to whoever might want it.
It was my first in the line of prototyping boards. It's been in a junk box for years and years and I used and abused it.
During one late night test I smoked the pots out of it so your first experiment would be a rebuild of the unit. Have no manual but if someone wants this PM me and I'll send it. This is for a beginer or learner and I'm in the US only.

[repairs online]

Re: Cheaper ESR meter

Hello,

......talk to me, arneson, send me an email at: erepairs@rediffmail.com, cost if any, etc. etc.


Sincerely

[DrRick]

Re: Cheaper ESR meter

If any one is beginning to consider circuit design I offer this experimenter to whoever might want it.
It was my first in the line of prototyping boards. It's been in a junk box for years and years and I used and abused it.
During one late night test I smoked the pots out of it so your first experiment would be a rebuild of the unit. Have no manual but if someone wants this PM me and I'll send it. This is for a beginer or learner and I'm in the US only.

Hi, I would love to have that Heathkit proto box. I have had several of them, aquired when I would buy the ham/electronics shop of an estate. Unfortunetly, I have given them all away to the under-privleged kids that I mentor in electronics.
Since my main interest is tube audio I figured rhat I would never need one. Now that I was forced into a very early retirement (spinal disease) I have been developing microphone preamps for recording studios which the proto box would be great for.
I'm glad I gave away the ones I had, a couple of those kids are now in thier 20's and working as ET's. Without the skills they learned they may well be in jail by now, or worse (dead!). I get a lot of enjoyment in "giving back"; I grew up living inbetween Bell Labs and Fort Monmoth and I had mentors from both. I managed to work my way through university and grad school working as an ET.
Have a gread day.
Peace,
DrRick

[arneson]

Re: Cheaper ESR meter

It's yours.

[duldog]

Re: Cheaper ESR meter

Hello,

Well duldog, there must be something wrong with your meter. I have not build the meter you are talking about (if someone could send me JUST the board, would greatly appreciated it), for a good cap over 10 microF, the ESR should be <= 1 Ohm. For a bad cap over 2 Ohm, lets say 3 Ohm.

33 ohms, as you say, is about at 50% deflection, therefore, for your meter to indicate 3 Ohm, the needle would have to be very close to where the reading for a good cap would read, making it very difficult to decide if it is a good cap or a bad cap.

Sincerely

boss, the circuit i built now looks exactly as the diagram shown on the first page. using test resistors of different values (1-10ohms), i was able to determine that the meter deflects to about 90% of the scale (needle moves to the right) with 1ohm R at its probes, about 70% at around 5ohms and it hardly deflects at about 33 ohms. i was just guessing if these readings indicates a reliable indication of the esr of the cap under test.

duldog

[repairs online]

Re: Cheaper ESR meter

Hello,

I quote

"good day everyone!

much to my regret, i've built this circuit even before i was able to read this thread.

anyway, is the circuit posted in the first page makes the meter read lower esr value better? the circuit i built reads about 1ohm at 95% deflection and about 50% deflection at 33 ohms."

From the above, in one of your previous posts (to be found on page 2), you have a deflection of about 50% at 33 ohm.

In you last post (page 3), you say that you have no deflectiion at 33 ohm.

I don't know which one to accept. As I have said, I have not built the meter and before doing so, I am looking for some insight info from those members that have.


Sincerely

[davmax]

Re: Cheaper ESR meter

If you serious about measuring ESR have thought about buying the ESR meter kit from Dick Smith or others. See link: http://members.ozemail.com.au/~bobpar/esrmeter.htmI can recommend it.

[repairs online]

Re: Cheaper ESR meter

Hello,

I already have Bob Parker ESR meter. However, the analog type, in my opinion, are much better, easier to read.

With Bob Parkers ESR, it becomes essential to look at the value of the capacitor and then compare it with the value on the table, however, this problem does not exist for the analogue meters I have read about, it is either good or is bad.

Getting a digital readout is not really such a great idea. What does it mean if the reading is slightly higher than the value indicated on the panel, the cap is bad????, I don't think so, I brought brand new caps where the reading was higher than indicated and they worked fine.

Reseting is also a problem with this digital ESR meter.

Of course, repairing the meter is another factor, if the micro on Bob's meter becomes defective ....well try to find another micro. Further, it can easily be damaged by charged caps.

[kc8adu]

Re: Cheaper ESR meter

i have the opposite experiance.
the low end resolution of the bob parker design is better.
btw i have the code here i found online so i can program a new micro if need be.
i also noticed that caps tend to be good or very bad by the time i am looking at a repair.

[willawake]

Re: Cheaper ESR meter

i also noticed that caps tend to be good or very bad by the time i am looking at a repair

same here, since i am looking at low esr caps only they are usually 0.0X when good and 0.XX or even X.XX when bad.

[repairs online]

Re: Cheaper ESR meter

Hello,

That proves my point, an analogue display ESR meter would pick up the faulty from the good ones easily without having to spent time on looking for capacitance values and voltages off the caps.

The only problem is with caps below 10 uF, perhaps special circuitry installed at the flick of a switch will take care of it.

Sincerely

[klq]

Re: Cheaper ESR meter

Regarding the schematic at the start of this thread can any one tell me what the diode next to r21 is? Also what are the resister values in brackets? Many thanks

[Raven21633]

Re: Cheaper ESR meter

Bob Parkers Digital ESR is among the best but you still have to shell out quite a pretty penny to get one. If you have a wife to account to (who's not so happy about what your spending on parts for your antique radios as it is) you have to look for less expensive solutions.

That's actually how I found this forum. I was planning to build the Nuova Elettronica ESR bridge and was desperately searching for anyone who sells a 1nf (10µf) Metalized Polyester or Mylar caps in the USA (the closest I came to the North American coastline was Ireland) when Google hit upon this thread I'm very happy it did! This looks like a wonderful project!

Raven