Where are all the ESR meters?

[Fred_Bartoli]

The Phantom a écrit :

It was a pun! No, wait, it was a palindrome!

If exaggerating for effect is called hyperbole, what is
under-exaggeration called? Hypobole?

There are two related:
- euphemism, which consist of understating to 'soften' what you say.
- litotes, which consist of saying less to imply more.

 

[Winfield]

How high is "high"?

Perhaps a better question is, how big is big?

Several designs we've been considering have a
pair of diodes to discharge the test capacitor
and limit the circuit voltages, but I've heard
these can fail with large, charged capacitors.

I think the issue isn't necessarily how high
the voltage (tube amplifiers get to hundreds
of volts), or how high the current delivered,
but how much energy is going to be dissipated
in the protection components that discharge
the guilty capacitor.

I'd say the answer is, the size of two fists.
I think we're talking about ~ 100J of energy.
Isn't that more than enough to blow out a
common glass diode and/or a 1/4-watt resistor?

 

[Jim Thompson]

Perhaps a better question is, how big is big?

Several designs we've been considering have a
pair of diodes to discharge the test capacitor
and limit the circuit voltages, but I've heard
these can fail with large, charged capacitors.

I think the issue isn't necessarily how high
the voltage (tube amplifiers get to hundreds
of volts), or how high the current delivered,
but how much energy is going to be dissipated
in the protection components that discharge
the guilty capacitor.

I'd say the answer is, the size of two fists.
I think we're talking about ~ 100J of energy.
Isn't that more than enough to blow out a
common glass diode and/or a 1/4-watt resistor?

Should be enough to crank you over a few times ;-)

...Jim Thompson

 

[Fred Bloggs]

Do you? Its well known on this group that I am now 100% disabled,
after almost 40 years of working in the electronics industry. Also, I
never claimed to be a circuit designer. yes, i have designed and built
equipment I couldn't find, or get before a critical deadline but it was
never for public consumption. Almost all were one off, and for whoever
I was working for at that time. A wide variety items, but of very
little interest to others.

What does your physical disability have to do with a complete absence of
any constructive circuit contributions to SED?

 

[Fred Bloggs]

Should be enough to crank you over a few times ;-)

...Jim Thompson

WH is stalling... input protection has little to do with a basic
measurement architecture. I had no idea this little project would be so
difficult for everyone

 

[Jim Thompson]

WH is stalling... input protection has little to do with a basic
measurement architecture. I had no idea this little project would be so
difficult for everyone

I know ;-)

...Jim Thompson

 

[John Larkin]

Perhaps a better question is, how big is big?

Several designs we've been considering have a
pair of diodes to discharge the test capacitor
and limit the circuit voltages, but I've heard
these can fail with large, charged capacitors.

I think the issue isn't necessarily how high
the voltage (tube amplifiers get to hundreds
of volts), or how high the current delivered,
but how much energy is going to be dissipated
in the protection components that discharge
the guilty capacitor.

I'd say the answer is, the size of two fists.
I think we're talking about ~ 100J of energy.
Isn't that more than enough to blow out a
common glass diode and/or a 1/4-watt resistor?

If it's a 4-terminal gadget, all you need to do is current-limit three
of the leads. My pfet current source does that inherently, with an
added diode for the other direction. Or spring for a few of those
Supertex depletion fets, or the protected SSRs.

I think the protections can be added once an architecture is settled
on. Basic issues:


Analog/needle or digital/uP?

Simple scalar impedance, or tease out the resistive component, or
resolve both real and imaginary parts?

Fixed or variable frequency?

Measure anything else? Capacitance? Resistance? Inductance?

Time or frequency domain?

John

 

[John Larkin]

WH is stalling... input protection has little to do with a basic
measurement architecture. I had no idea this little project would be so
difficult for everyone

Interesting that for a proposed "group design", hardly anybody is
willing to make a first step. The psychology of group design is
fascinating, and it turns out that an audience is a huge inhibition;
people tend to not expose ideas if they fear they are imperfect, and
might give some nit-picker grounds for public criticism.

Brainstorming is delicate because people are fragile. At my place, we
scribble goofy ideas on a whiteboard, do a lot of stupid stuff (don't
distinguish between circuit-as-proposal and circuit-as-joke), argue
and laugh a lot, and sometimes come up with brilliance, with no way to
tell who gets the credit. Some people just can't play at this game.

John

 

[John Larkin]

What does your physical disability have to do with a complete absence of
any constructive circuit contributions to SED?

Hey, Fred, post an ESR circuit!

John

 

[Jeff L]

Perhaps a better question is, how big is big?

Several designs we've been considering have a
pair of diodes to discharge the test capacitor
and limit the circuit voltages, but I've heard
these can fail with large, charged capacitors.

I think the issue isn't necessarily how high
the voltage (tube amplifiers get to hundreds
of volts), or how high the current delivered,
but how much energy is going to be dissipated
in the protection components that discharge
the guilty capacitor.

I'd say the answer is, the size of two fists.
I think we're talking about ~ 100J of energy.
Isn't that more than enough to blow out a
common glass diode and/or a 1/4-watt resistor?

Protection is easy - read the voltage across the cap in question with a
comparator, if it is more then a few volts, have a indicator displayed to
discharge the cap first. If it is below a few volts, connect the cap to the
metering circuitry with a couple of low RDS on FET's.

 

[John Popelish]

Interesting that for a proposed "group design", hardly anybody is
willing to make a first step. The psychology of group design is
fascinating, and it turns out that an audience is a huge inhibition;
people tend to not expose ideas if they fear they are imperfect, and
might give some nit-picker grounds for public criticism.

Brainstorming is delicate because people are fragile. At my place, we
scribble goofy ideas on a whiteboard, do a lot of stupid stuff (don't
distinguish between circuit-as-proposal and circuit-as-joke), argue
and laugh a lot, and sometimes come up with brilliance, with no way to
tell who gets the credit. Some people just can't play at this game.

I think that the medium is more the problem than what the
people involved can or cannot play at. Try using an
archived text posting medium for your next brainstorming
session and see how that works out.

We are using a poor tool for this job.

 

[Fred Bloggs]

Hey, Fred, post an ESR circuit!

John

Most definitely, and primarily to elicit critique from "Michael
Terrell," a self described "I never claimed to be a circuit designer"
type, who is always long on superficial opinion and woefully short of
usefulness.

 

[Fred Bloggs]

Interesting that for a proposed "group design", hardly anybody is
willing to make a first step. The psychology of group design is
fascinating, and it turns out that an audience is a huge inhibition;
people tend to not expose ideas if they fear they are imperfect, and
might give some nit-picker grounds for public criticism.

Brainstorming is delicate because people are fragile. At my place, we
scribble goofy ideas on a whiteboard, do a lot of stupid stuff (don't
distinguish between circuit-as-proposal and circuit-as-joke), argue
and laugh a lot, and sometimes come up with brilliance, with no way to
tell who gets the credit. Some people just can't play at this game.

John

Well whatever...the task is straightforward and does not require a great
amount of ingenuity. The ingenuity comes in deciding the functionality
of the meter. In my opinion there is nothing to accomplish by going half
way to an impedance analyzer, there are already plenty of compact and
fully functional products in that niche. The key is to produce the
simplest possible design that measures ESR, if something else comes free
along with that without introducing one iota more of complexity then
fine, but if it requires one speck of dedicated hardware not useful for
determining ESR then it goes. This will require that you discover
something inherent to ESR that allows for a very simple circuit
architecture. That is all the help I am going to give you at this stage

 

[John Larkin]

Well whatever...the task is straightforward and does not require a great
amount of ingenuity. The ingenuity comes in deciding the functionality
of the meter. In my opinion there is nothing to accomplish by going half
way to an impedance analyzer, there are already plenty of compact and
fully functional products in that niche. The key is to produce the
simplest possible design that measures ESR, if something else comes free
along with that without introducing one iota more of complexity then
fine, but if it requires one speck of dedicated hardware not useful for
determining ESR then it goes. This will require that you discover
something inherent to ESR that allows for a very simple circuit
architecture. That is all the help I am going to give you at this stage

Thanks for the excellent illustration of my point. You are far more
concerned about your ego than you are about the technology. Probably
that explains why you don't design electronics.

There's a great irony here; that is all the help I am going to give
you at this stage.

John

 

[John Larkin]

Most definitely, and primarily to elicit critique from "Michael
Terrell," a self described "I never claimed to be a circuit designer"
type, who is always long on superficial opinion and woefully short of
usefulness.

Don't post it to elicit criticism. Post it to elicit suggestions,
improvements, riffs, history, amazement.

John

 

[john jardine]

If it's a 4-terminal gadget, all you need to do is current-limit three
of the leads. My pfet current source does that inherently, with an
added diode for the other direction. Or spring for a few of those
Supertex depletion fets, or the protected SSRs.

I think the protections can be added once an architecture is settled
on. Basic issues:


Analog/needle or digital/uP?

Simple scalar impedance, or tease out the resistive component, or
resolve both real and imaginary parts?

Fixed or variable frequency?

Measure anything else? Capacitance? Resistance? Inductance?

Time or frequency domain?

John

Analogue, 0 to 1 ohm resistance (linear down to a few mohms), in series with
1uF and above.
Discharge protection, Kelvin sensing etc, just added fluff. It's a core idea
that will offer the interest and Laurels.
Q's of even a 100 require a board full of bits. The ESR problem is up in the
1 part in a 1000 area.
Fred seems to have something up his sleeve. I'm intrigued

 

[DaveC]

Measure anything else? Capacitance? Resistance? Inductance?

Not being a designer, I won't participate (and you wouldn't want me to!) in
the process. But please consider that an ESR meter can -- if designed with it
in mind -- be handy at measuring things such as resistance of battery cells,
giving indication of relative age. With the dozens of rechargeable AA cells
lying around, I want to know how they're getting on in years...

A small problem is that if you put in diode protection, measuring cells is
out unless you decide to switch the protection on and off. Or come up with a
more elegant solution...

 

[Winfield]

Right. I know, because I *have* been cranked,
more than once. :-(

WH is stalling... input protection has little to do
with a basic measurement architecture. I had no idea
this little project would be so difficult for everyone

I'm not stalling; my paper sketches nicely handle
the protection requirements I posted. Basically
my design is a simplified version of the HP meters
I have, based on the fact that 5% accuracy is good
enough. I've been slowed down a bit by the need to
evaluate single-supply instrumentation amplifiers,
etc. And by my real projects: working on the book,
home projects like my rust-infected Japanese Kerria,
my Honeysuckle arbor, and of course, my Harvard job,
with 1T generators, TEC drivers, -- things like that.

 

[Michael A. Terrell]

What does your physical disability have to do with a complete absence of
any constructive circuit contributions to SED?

Well, Fred, you claim to be in perfect health, yet you haven't even
submitted a set of specifications for YOUR ESR meter design. On the
other hand, you've already dammed designs of others you hadn't even
seen.


As far as your questioning what my disabilities have to do with
anything proves once again just what a fucking asshole you are. You
have no idea how bad my health is but like everyone else here, your over
inflated ego MAKES you damn everything and everyone in sight.

I'll tell you what. Go buy a cane. Strap 75 pounds on your back and
try to do the usual day to day things you HAVE to do to survive. Cut 15
to 20 weeping sores on your legs, and try to get by on no quality sleep,
at all. I don't really sleep anymore. I pass out from exhaustion. Try to
breathe through several layers of mask so you're always short of breath.
Then exert yourself till you feel faint.

There is no way you can simulate most of the side effects of all the
medications. About the only one you can get close to is to alternate
between Magnesium Citrate and Imodium A-D, several times a day. How
would you like to go from starting the day constipated, with a stool so
hard that your ass bleeds, to diarrhea and back to constipated in a
single day?


If I DON'T take ALL of the medicine I can get some sleep, but both my
blood pressure and blood sugar go sky high. I generally have less than
two hours a day to do anything that requires concentration and/or
exertion, so why waste it on a circuit design I can't afford to build?

I WAS working on a design for a computer interfaced ESR meter to
allow quick go/nogo or incoming inspection testing to read both the
capacitance and ESR, and see if they were in spec, when I lost my job on
Sept. 7th, 2001. I was already so sick I couldn't function, and people
laughed in my face when I applied for work. I was stopped by a cop one
day and accused of being drunk, because I couldn't walk a straight
line. Even walking with the cane, assholes like you do their best to
block my way, or try to knock me down. On punk tried to take my cane,
but soon regretted it because his arm was twisted into a knot behind his
back. he was on his knees, begging me to let go. He had ignored my good
right arm that still works, so I grabbed the other end of the cane and
twisted it, and his arm behind his back and pined him so he couldn't let
go.

I had to wait over two years to get any medical help from the VA.
During that time I lost so much strength that I couldn't walk. Even
though I was eating under 1200 calories a day, I put on over 100 pounds.
I topped out at 297 pounds. So far, I have lost 25 pounds, in the last
two years. Its going to take a long time to ever get close to the
normal 180 pounds I was, before I got sick.

You have no damn idea what its like to be severely disabled and a lot
of fucking nerve. Have you EVER heard of anyone else who got 100%
disability in less than two months? Does that tell your pea brain
anything, at all?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[ehsjr]

Protection is easy - read the voltage across the cap in question with a
comparator, if it is more then a few volts, have a indicator displayed to
discharge the cap first. If it is below a few volts, connect the cap to the
metering circuitry with a couple of low RDS on FET's.

Just use a spring return spdt toggle.
Toggle to test.

Ckt ---o
o<--o---- to DUT
|
Gnd ---+-------- to DUT