Well said Harvey.
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On Sat, Mar 14, 2020, 4:14 PM Harvey White <madyn@...> wrote:
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
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
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.
On 3/14/2020 11:35 AM, Ernesto wrote:
LOL! You people have to spend one hundred dollars in gadgets like theDE-5000 to measure ESR?
design and development of complex electronic hardware and firmware, I enjoy
As a professional electrical engineer with large experience in the
the use of my ONE RESISTOR ESR meter (see my previous post).
capacitors mounted on a dual preamplifier board that is over 40 years old.
I measured (for fun) in 10 minutes the ESR of about 10 electrolytic
the electrolytic, and the probe on its positive.
- I clipped the ground of the oscilloscope X1 probe on the negative of
- I clipped to the ONE RESISTOR of 1000 ohm a 10V positive 100Khz signalfrom 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 inthe 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!