Re: recommended ESR meters these days


Harvey White
 

There's a tradeoff here.

When I was (very) much younger, I built things from whatever I could get from old TV sets, a source of which (non functioning) I was lucky enough to find.  I traded off time stripping the old TVs for parts I did not have the money to buy.  And yes, there was a store near me that likely had every part I needed.  I couldn't get there, and I didn't have the money.

When I had a steady job, some years after I'd gotten out of college, I had a better lab, a few more parts, some more ambitious designs, and I'd started gathering parts from the local university or the throwaways from the business where I worked.  Most of my money went into infrastructure, such as better test equipment and a unimat lathe.  (You try making holes in a plate of aluminum for mounting a C mount camera lens (used epoxy and a nut from a light assembly (1-20 thread, Imperial), and grinding cone to make the hole.)

Once I got enough money, and the like, I started buying things where the things that I wanted were easier to buy, without having to invent the infrastructure, make the case, make the PC board, design it, debug it, and THEN continue with what I wanted to do when I decided I needed one of those.

Different people have different resources at differing times of their lives.  Some are lucky, some not.  Some are lucky enough to build everything, some need more.

As far as ESR is concerned, I do have a Sprague LC75, and an HP 4262A, both of which work.  I've been lucky.

Time vs money is a tradeoff everyone makes.

Harvey

On 3/14/2020 11:35 AM, Ernesto wrote:
LOL! You people have to spend one hundred dollars in gadgets like the DE-5000 to measure ESR?

As a professional electrical engineer with large experience in the design and development of complex electronic hardware and firmware, I enjoy the use of my ONE RESISTOR ESR meter (see my previous post).

I measured (for fun) in 10 minutes the ESR of about 10 electrolytic capacitors mounted on a dual preamplifier board that is over 40 years old.

- I clipped the ground of the oscilloscope X1 probe on the negative of the electrolytic, and the probe on its positive.
- I clipped to the ONE RESISTOR of 1000 ohm a 10V positive 100Khz signal from my function generator (with the same ground as the oscilloscope), and touched with the other lead of the resistor the positive of the capacitor under test. The resistor became in fact a current source.
- I observed on the oscilloscope, set to 10 mV/div, the 100Khz signal in the equivalent scale of 1 ohm ESR per division. I found some good capacitors and many bad ones! (its amazing how well an amplifier can work even with some "bad" electrolytics...)

It could not be easier!

Ernesto


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