--- In Electronics_101@..., John Johnson <johnatl@m...>
wrote:

Sorry this happened to you. I got stuck on 320v when I was a

teenager,

fortunately my mother pulled me off of it. I was dying, and know

it

isn't any fun.

This is why everyone should use lock-out tag-out every time,

without

fail.
There should also be documented de-energizing procedures for every
device in the facility.

My company won't even buy the LOTO equipment for me.

Regards,
JJ

I had my lockout hanging on my belt actually. I never work on
electrical equipment without locking out and PROVING that the power
is off. In this case though, why would anyone lock out when you're
only looking at the fixture - without even taking the lens off?
Thats like saying you would need to lock out your table lamp at home
before you could touch it to turn it on or off.

This was installed prior to my employer hiring a full time
Electrician (same time I started). All work was done by electrical
contractors who are required to be licensed by law here. No ticky,
no worky! Being ticketed just means you know HOW to do things
correctly, not that you WILL do them that way.

Where I live, only a homeowner working on thier own home is allowed
to do electrical work without a license. Even then, they still have
to get permits and be inspected prior to energizing. The only reason
we're allowed to do the minor electrical work is that the employer
takes out an annual permit and we work under the direction of the
ticketed electrician. Any work we do is inspected by the electrician
and only the electrician is allowed to energize the circuit after
repairs/installation. He has to check out each person before they're
allowed to even pick a voltage tick, never mind actually touch a
power cord.

This is why everyone should use lock-out tag-out every time, without
fail.

Well, if you are only going to touch a thing like this lamp fixture which
should never ever be at dangerous potential it is hard to do that.

(e.g. where do you switch off before you touch the metal
fuse compartment for switching off the power.)

What i want to say is if one stupid guy is doing improper work you have most trouble
working after him.

One good idea would be to always use one of those screwdrivers with a indicator lamp.
it is by no means a 100% safety thing but it takes little enough time and work to touch
a chassis with it that you might actually use it.

Licensing is one possibility to keep certain standards,
but it is never perfect.

The dangerous thing is if people are forced to do things faster and cheaper
than they can be done properly.

ST

Looks like Flash is a type of EEPROM:




Mike



--- In Electronics_101@..., Mario Lopez <linked82@y...>
wrote:

the part number sounds like an EEPROM.
Those aren't the same as flash, are they?
--
They're not? I thought they were.

--

No, the only similar chips are 28Cxxx, like 28C17, 28C64 and

28C256; these are EEPROMS, not FLASH EEPROMS, that are named 28Fxxx.
A bit confusing :)

---------------------------------
Correo Yahoo!: 6MB, más protección contra el spam ?gratis!

Regards,
JJ

Your cable or satellite can replace your box if it isn't working.

Regards,
JJ

Sorry this happened to you. I got stuck on 320v when I was a teenager,
fortunately my mother pulled me off of it. I was dying, and know it isn't any fun.

This is why everyone should use lock-out tag-out every time, without fail.
There should also be documented de-energizing procedures for every
device in the facility.

My company won't even buy the LOTO equipment for me.

Regards,
JJ

On Sun, 18 Apr 2004 16:37:37 -0000, Steve <alienrelics@...> wrote:

As you say, the turn on point shifted... but the turn off point does
-not- shift.

Still assuming totally resistive loads: Since the current in the load
is in phase with the voltage on the load, but the voltage before the
triacs does not shift or change, then the current is shifting phase
relative to the incoming voltage.

Where is the capacitance? In the dimmer circuit.

The current and voltage peak at the output may be at the same
unshifted spot (at least until you go beyond 90 degrees) but if you
filtered it down to the 60Hz original you'd see an overall phase shift.

I've repaired stage lighting controllers, too, and even designed a couple.

Alien Steve

I really wonder if a power meter measures less than U*I.
i think a power meter multiplies the two signals, so there shoul be nothing
missed out...
Still there is the question if there is any reactive power or not.
I would say there can't be but i am not sure.
I agree with the phase shift explanation Steve has given, but it doesn't fit together.
on the one hand there is phase shift, on the other hand there should be no reactive power.

Any ideas how to check this? anyone having a wattmeter?

ST

Here is an interesting layout software. www.pulsar.gs/nwc
Richard

As you say, the turn on point shifted... but the turn off point does
-not- shift.

Still assuming totally resistive loads: Since the current in the load
is in phase with the voltage on the load, but the voltage before the
triacs does not shift or change, then the current is shifting phase
relative to the incoming voltage.

Where is the capacitance? In the dimmer circuit.

The current and voltage peak at the output may be at the same
unshifted spot (at least until you go beyond 90 degrees) but if you
filtered it down to the 60Hz original you'd see an overall phase shift.

I've repaired stage lighting controllers, too, and even designed a couple.

Alien Steve

--- In Electronics_101@..., "Curtis Sakima" <csakima@m...>
wrote:

I used to work fixing stage-n-lighting light dimmers. We used
oscilloscopes triggered by the incoming line AC. The output sine-wave
never shifted left and right as dimming was varied. Just the sharp
vertical line from "zero" where the triac triggered ... went "left and
right".

Curtis

Dazzle Mom this coming Mother's Day season with flowers!




----- Original Message -----
From: Steve <alienrelics@y...>

Since the turn on point is delayed: The voltage and current in a

resistive

load are in phase. However, if you look at the voltage coming into

the whole

circuit, the current phase is delayed because of the delay between zero
voltage crossing and when the triac turns on and causes the start of

current

flow.

开云体育

? hai,

what is flash memory.
i thought it is used in cell phones.

please share any technical idea.

murugaiyan

________________________________________________________________________
Yahoo! India Matrimony: Find your partner online.

---

: 6MB, m???s protecci???n contra el spam ???gratis!

Well I graduated in 1966. Took Electronics last 2 years of HS.
Lost 2 good jobs during the mid 80's when all the companies were
merging and again 2 jobs after 911 due to business going down.
Decided to start my own.
I was very lucky as I was growing up that people would spend time to
show me the things about electronics. I try to pass it on to others
that need it and willing to learn. That is why this forum is good.
There are a lot of knowledgeable people on here so the beginers can
learn a lot.

Ken Smith

On Sun, 18 Apr 2004 14:04:27 +0100 (BST), murugaiyan mahalingam <murugaiyan_m@...> wrote:

HAI,

i don't have idea bout set top box.
if anybody have please share ideas and complete
discriptive material.actually i searched about set top
box but not get any technical details


murugaiyan

which set top box?

where is the box set upon and what does it do?


ST

hai,

what is flash memory.
i thought it is used in cell phones.

please share any technical idea.

murugaiyan

________________________________________________________________________
Yahoo! India Matrimony: Find your partner online.

HAI,

i don't have idea bout set top box.
if anybody have please share ideas and complete
discriptive material.actually i searched about set top
box but not get any technical details


murugaiyan

________________________________________________________________________
Yahoo! India Matrimony: Find your partner online.

ya, that is correct but not only angle shift
capacitor charging and rises the voltage level.
In the inductive component rises the current level.
i don't know how is it possible. but practically i
feel

--- JanRwl@... wrote: > In a message dated
4/17/2004 8:53:47 PM Central

Standard Time,
csakima@... writes:
I thought only capacitive/inductive elements creates
angle shifts .......??
Curtis is correct.

________________________________________________________________________
Yahoo! India Matrimony: Find your partner online.

I also facing this problem everyday. i don't have any
special equipment. anybody have some idea pl give that
is very helpful
murugaiyan

--- Keith <keith@...> wrote:
---------------------------------
--- In Electronics_101@..., "Kenneth
Smith"
<kensmith52@y...> wrote:

What method of soldering do you use. I have done

some research on

this and found many ways but none seem reasonable.
I can make the boards but have not figured a way to

solder them.

Thanks
Ken Smith

A tip given to me for SMD rework which I use for very
fine pitch
TQFPs: smother the legs with solder then use de-solder
braid to remove
the excess. It leaves the solder connecting the legs
to the board but
removes all the short circuits.

Keith.



---------------------------------
Yahoo! Groups Links

To visit your group on the web, go to:


To unsubscribe from this group, send an email to:
Electronics_101-unsubscribe@...

Your use of Yahoo! Groups is subject to the Yahoo!
Terms of Service.


________________________________________________________________________
Yahoo! India Matrimony: Find your partner online.

Sorry to be OT here, but I get upset at some of the stupid
licensing regulations we have in this country.

And how many more people would kill themselves or others if there
were no licensing or regulations?

An idea doesn't have to be perfect for it to still be a good idea.

Mike


--- In Electronics_101@..., "Rod Baxter"
<rod.baxter@b...> wrote:

Unfortunately even experienced electricians can get caught. About 15
years ago I was installing a mainframe computer which had a large
Frequency converter to run it, about 50 KVA. The inspector who

came to

check on the electricians work checked the output of the converter

and

said it wasn't working. I grabbed his hand as he went to touch it

and

stopped him electrocuting himself. What he had done was use his

phase

rotation meter to check the output and it did not work at 400Hz

which

was the output of the converter. I used my meter and showed him it

was

working, he went a bit pale and left! I am not a licensed

electrician

but I suspect I know more about electricity (and the regulations)

than

some electricians unfortunately.

Anyone can make a mistake I guess, the trick is to make sure they

are

not fatal..

Sorry to be OT here, but I get upset at some of the stupid licensing
regulations we have in this country.

Rod