Getting old

[Pat]

Similar to Arfa not being able to see parts on the floor...
Yesterday, I decided to connect a simple circuit to tell me if I left
the garage door open when going to bed. I found a reed switch and
matching magnet in my junk box as well as an LED (with built in
current limiting resistor) and a left over wall-wart power supply.
After connecting it all up I realized the LED was on when the door was
closed rather than open which I preferred. I didn't have a N.O.
switch but I did find an old piece of breadboard and a 2n3904
transistor. All I needed was a 10K resistor to use as a pull up to
make my own inverter. I also wanted to add a 470 ohm R in series with
the LED to lower the current a little. Bottom line: It all works
well, but took way longer than expected. Why? It took a long time to
find the right R's in my old box containing hundreds of 1/4 w R's. The
1/4 Watt resistors in my box clearly have shrunk over the last 30
years! And, the color stripes have all faded to the same shade of
darkness, too. I kept pulling 4700 ohm R's from the box when looking
for the 470 because the red stripe looked brown to me. I'm glad I
don't do this for a living anymore!
Pat

[petrus bitbyter]

"Pat" <p...@nospam.us> schreef in bericht
news:q2t6p85mfomovl5dh...@4ax.com...

Well, growing old may not be funny. Being old even less. But it seems to be
the only way to live longer and most of us want to.

As for the colors on resistors, they are often unreliable even on new ones.
Even with perfect eyes that can see all colors sharp and clear you often can
only guess what color it is supposed to be. So I always keep my Ohm-meter
nearby.

petrus bitbyter

[amdx]

My daughter went to a hamfest with me and bought a small electronic
kit for her husband to build. I'm helped him learn to solder and recited
a color code mnemonic for him. After a few mistakes reading the
resistors, I found out he has some color blindness.
Be glad you didn't have that problem.
Mikek

[John Robertson]

Ohm-meters work even if you are partially colour blind...I have always
used them due to my red/green deficiency that I first recognized in a
Time/Life book back in the 60s...

John :-#)#

--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

[amdx]

I did give him the meter and showed him how to use it, and then
explained about tolerance, and then told him about his body resistance
and measuring high value resistors.
Mikek

[tm]

"amdx" <am...@knology.net> wrote in message
news:84d92$5193a2e1$18d66b6a$26...@KNOLOGY.NET...

A long time ago, resistors had the value printed on them.
I believe they were Ohmite resistors.

[hrho...@sbcglobal.net]

>        "Old pinballers never die, they just flip out."- Hide quoted text -
>
> - Show quoted text -

I am fortunate that my wife is willing to help me with resistor color
codes <g>..

I always knew I had a problem, even in high school 60+years ago. But
in college I was never tested for that, so I assumed everyone had
similar problems telling red-green-brown-gray, After we were married,
I would ask her to confirm my codes, and she made it seem so simple
that I got tested and was found to be just partially red-green
deficient. For everyone, as a brightly colored light goes into the
distance, the person can tell the light is lit, but not the color.
For me, I lose the ability to tell the color whan the light is fairly
close by. It is a matter of what the angle of the light subtends in
my retina, I apparently have fewer of the receptors that
differentiate between colors and so unless the light subtends a fairly
large angle, I can't tell red from green, etc.

However, when it comes to setting up a color tv set, I have no
problems because the area I am looking at subtends a very large area
of the retina. 10% of males have this problem, around 3% or less of
females.

[Phil Allison]

"Pat"

( snip)

> Why? It took a long time to
> find the right R's in my old box containing hundreds of 1/4 w R's. The
> 1/4 Watt resistors in my box clearly have shrunk over the last 30
> years! And, the color stripes have all faded to the same shade of
> darkness, too. I kept pulling 4700 ohm R's from the box when looking
> for the 470 because the red stripe looked brown to me.

** The coloured bands on resistors do fade with age and red/brown confusion
is common depending on the body colour.

You DO need a bright light, NOT incandescent but fluoro with a "daylight"
white character.

A small magnifier may help too, but checking with an ohm meter is the
safest.

Particularly with any 1% types.


... Phil

[Robert Macy]

On May 15, 10:21 pm, "Phil Allison" <phi...@tpg.com.au> wrote:
>...snip....

> A small magnifier may help too, but checking with an ohm meter is the
> safest.
>
> Particularly with any 1% types.
>
> ...  Phil

If you've ever gotten a package of 'mismarked' resistors; you will
ALWAYS check with an ohmmeter. Especially watching the effect of
putting 10 ohm resistors into the location meant for the power
dissipation of a 10k ohm resistor! Or, the package I once got with the
color bars painted in REVERSE order?! But since covered the whole
body, not immediately discernible.

[Phil Allison]

"Robert Macy"
"Phil Allison"

>
>...snip....
>
> A small magnifier may help too, but checking with an ohm meter is the
> safest.
>
> Particularly with any 1% types.
>

If you've ever gotten a package of 'mismarked' resistors; you will
ALWAYS check with an ohmmeter. Especially watching the effect of
putting 10 ohm resistors into the location meant for the power
dissipation of a 10k ohm resistor! Or, the package I once got with the
color bars painted in REVERSE order?! But since covered the whole
body, not immediately discernible.

** How do you tell the coloured bands are in the reverse order ????

Does the value change dramatically if you apply ohm meter leads the other
way around ?




... Phil

[Geoffrey S. Mendelson]

Robert Macy wrote:
> If you've ever gotten a package of 'mismarked' resistors; you will
> ALWAYS check with an ohmmeter. Especially watching the effect of
> putting 10 ohm resistors into the location meant for the power
> dissipation of a 10k ohm resistor! Or, the package I once got with the
> color bars painted in REVERSE order?! But since covered the whole
> body, not immediately discernible.

I ordered some blade type fuse holders and fuses from a Chinese eBay vendor.

After 2 months they had not arrived, so they sent me another set. Eventually
I got both sets, with any indication of when they were mailed or from
whom removed.

The fuses are small flat clear plastic cases with a fuse element inside,
and a color coding for the amperage and the number stamped on top.

The assortment was supposed to be 5, 7.5, 10, etc. However it seems that
the 5 and 40 amp fuses are both the same shade of red. One batch came
with 5 amp fuses, the other came with 40.

To really mess things up, the wire on the fuse holders was stated as 3.5mm,
and they came with 20 amp fuses. The wire was 3.5 mm including insulation,
the conductor was closer to 1.5mm. I would not want to use a 20 amp fuse
with it.

Since I already had (and paid for) two sets of the holders and fuses, I
notified the vendor of the problem but did not ask them to replace anything.

Last I looked, they had not updated their listing.

Geoff.


--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379
It's Spring here in Jerusalem!!!

[hrho...@sbcglobal.net]

On May 16, 8:34 am, "Geoffrey S. Mendelson" <g...@mendelson.com>
wrote:

Here is the Chicago area of the USA also. Electronics taking a back
seat to getting the tomatoes, beans and other veggies planted.

[Arfa Daily]

"Pat" <p...@nospam.us> wrote in message
news:q2t6p85mfomovl5dh...@4ax.com...

Ah, but were you looking at them under one of those crap CFL light bulbs. A
while back, I put one in my bench light, and then found that I could no
longer read resistors. The spectrum is so discontinuous that I was finding
that it was almost impossible to tell brown from orange from red, and purple
from blue or grey. Normal service was resumed when I went back to a 'proper'
light bulb. Trouble is that frosted ones that give a nice even light across
the work area, are now almost impossible to obtain because of all this
eco-bollox nonsense, so I've since made an adaptor from fixing a bipin
holder into a bayonet base culled from a CFL that failed after about 10
hours service (this is the only decent use I've ever found for one), and I
now run the light from an old 12 volt lighting transformer, using a dichroic
halogen bulb fitted into the adaptor. The light is a bit 'streaky' compared
to a frosted bulb, and doesn't spread as far across the bench due to the
shape of the reflector on those bulbs, but at least it does a 'proper' job
of illuminating boards, and the colours of the resistors are right and
readable.

I used to keep all my resistors in a total of perhaps six or seven drawers.
Sort of "1 ohm to 100 ohms", "101 ohms to 1K" and so on. But like you, as
the bloody things got smaller and more complicated to read with 4, 5 and
even 6-band marking systems, I did a major revamp of the storage, and now
every value has its own drawer. I've only done this to E12 values level
though. Any 'in-betweens' from the E24 range are put in the nearest value
drawer with a bit of yellow tape around them, and the value written on in
Sharpie. It's amazing how much time this has saved trawling through drawers
with tangles of resistors of all different values in them ... :-)

Arfa

[Arfa Daily]

"amdx" <am...@knology.net> wrote in message
news:84d92$5193a2e1$18d66b6a$26...@KNOLOGY.NET...

From tests that were done on me when I was a kid, it was determined that I
had some colour blindness. I think that it was something like green blind
and red insensitive, meaning that I could not distinguish some shades of
green at all, and had difficulty with distinguishing some colours amongst
others. I was told that I would never have a career in anything electrical,
because I would not be able to distinguish wire colours in a bunch ...

Hmmm ... is all I can say to that. I have never had the slightest problem in
that regard, and have been in electronic service, working to component
level, for over 40 years. I guess that the brain just learns to compensate,
as it does when you wear yellow or blue tint sun glasses. Constancy of
colour is it called ? However, it does make me wonder if that is part of the
reason that I have trouble distinguishing colours under the discontinuous
spectrum of eco-bollox light bulbs. If my brain has learnt to compensate for
the deficiencies of my eyes, under sunlight, and incandescent light which
has a similar smooth spectrum, maybe it confuses the whole issue if some of
the wavelengths of light that it is using to calculate the compensations,
are completely missing ?

Arfa

[Cydrome Leader]

On a tangent- how do people here organize their resistors and other parts?

By range or by the first significant digits?

I don't do repair work full time, so I just have boxes of stuff, mostly in
smaller bags already marked with values since I just get those
"engineering sample kits" from digikey to cover common ranges of stuff.

I can't stand the screech of those little plastic parts drawers so I never
use them.

[Arfa Daily]

"Cydrome Leader" <pres...@MUNGEpanix.com> wrote in message
news:kn6fda$967$1...@reader1.panix.com...

Mine don't screech, and I've got hundreds ! I debated long and hard how to
re-organise my resistors, and eventually decided to keep them together by
decades. So the first four drawers have 0.1 ohm, 1 ohm general, 1 ohm
fusible and 1 ohm w/w. Next comes the varieties of 10 ohm, then 100 ohm,
then 1k, 10k, 100k, 1M, 10M. Then it moves onto the "15's" as in 1.5 ohms,
15 ohms, 150, 1.5k, 15k and so on. The last drawers are the "82's".

I don't know in the end if this was the best way to do it, but I quickly got
used to it, and am now able to reach to the right area for a value, without
even looking.

Arfa

[tm]

"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:lTAlt.86729$1g2....@fx08.fr7...

That's how I do it for 5% parts. The third band selects the drawer.

tm

[Michael A. Terrell]

Cydrome Leader wrote:
>
> On a tangent- how do people here organize their resistors and other parts?
>
> By range or by the first significant digits?
>
> I don't do repair work full time, so I just have boxes of stuff, mostly in
> smaller bags already marked with values since I just get those
> "engineering sample kits" from digikey to cover common ranges of stuff.
>
> I can't stand the screech of those little plastic parts drawers so I never
> use them.

Two values per drawer, with a divider. From 1.0 ohm to 22 Megohm.
Most of the drawers are close to full.

Wax the bottoms of the drawers and they are very quiet.