On Friday, September 6, 2013 6:29:13 AM UTC-7, Tim Schwartz wrote:

There are the source indicators (PHONO, FM, AM, TAPE, AUX, ....) NOT the
dial scale lamps, which are 'fuse type'.

--Tim

I guess I never had to replace any of those in my sets.....;-)

I hesitate to enter the fray, but if I thought 12V lamps were brigth enough, I would just use those. That might be easier to find. Operating at 8V, they would probably last a very long time (the GE rule of thumb from the middle of the last century was the twelfth power of the voltage).

On 7/09/2013 5:41 AM, wrote:
On Friday, September 6, 2013 6:29:13 AM UTC-7, Tim Schwartz wrote:

There are the source indicators (PHONO, FM, AM, TAPE, AUX, ....)
NOT the dial scale lamps, which are 'fuse type'.

--Tim

I guess I never had to replace any of those in my sets.....;-)

I hesitate to enter the fray, but if I thought 12V lamps were brigth
enough, I would just use those. That might be easier to find.
Operating at 8V, they would probably last a very long time (the GE
rule of thumb from the middle of the last century was the twelfth
power of the voltage).


**Except that is a REALLY dumb idea. The dial scale in the old Marantz
recievers is blue. Incandescent lamps emit very little energy in the
blue end of the spectrum (which is why Marantz had to use large numbers
of lamps in the first place - Technics and Pioneer models of the time
managed to use two or three lamps, whilst Marantz employed as many as
9). Operating an IC lamp at reduced Voltage will reduce blue output
still further, thus causing the dial scale to be quite dark and possibly
unusable. Blue LEDs are the perfect solution. Indefinite life-span, low
heat dissipation and perfect colour rendition. White LEDs are also
excellent, but with a shorter life-span and sligtly inferior colour
rendition.

--
Trevor Wilson www.rageaudio.com.au

On Friday, September 6, 2013 1:39:08 PM UTC-7, Trevor Wilson wrote:

**Except that is a REALLY dumb idea. The dial scale in the old Marantz
recievers is blue.

Maybe, maybe not. If I had one in my inventory/junque box, I would consider it a cheeap expeeriment and give it a try. If I could get one for about a dollar, I would consider taking a chance. You may have a differnt tolerance for taking this kind of risk.

On 7/09/2013 7:53 AM, wrote:
On Friday, September 6, 2013 1:39:08 PM UTC-7, Trevor Wilson wrote:

**Except that is a REALLY dumb idea. The dial scale in the old
Marantz recievers is blue.

Maybe, maybe not. If I had one in my inventory/junque box, I would
consider it a cheeap expeeriment and give it a try. If I could get
one for about a dollar, I would consider taking a chance. You may
have a differnt tolerance for taking this kind of risk.


**It's not a risk. It's just a dumb idea that won't provide any
worthwhile benefit.


--
Trevor Wilson www.rageaudio.com.au

"dave"
Phil Allison wrote:
"dave"


If you see "flicker" at 30 Hz you must hate television.


** Huh ???

The refresh rate of CRT based TVs is at least 50Hz - because of
interlaced scanning.

There is still massive strobing if you wave an object in front of one, as
the dots / stripes go dark long before the next refresh cycle.

A LED ( any colour ) pulsed at 30Hz flickers obviously - this stops at
about 40 to 45 Hz.


TVs today go down to 24 FPS progressive.


** Completely irrelevant.

Wot a dumbass.


..... Phil

**Except that is a REALLY dumb idea. The dial scale in the old Marantz
recievers is blue.

Maybe, maybe not. If I had one in my inventory/junque box, I would consider
it a cheeap expeeriment and give it a try. If I could get one for about a
dollar, I would consider taking a chance.

** Wide angle, 5mm blue LEDs sell for about $1.00 each.

The correct 8V bi-pin lamps will cost you more.

You will need one resistor ( 470 ohms to 1kohms) for each LED and just
ignore the insane crap here from AD etc about visible flicker at 60Hz.


.... Phil

"Phil Allison" wrote in message
...

"Arfa ****WIT Daily"
"Phil Allison"


** LEDs are, believe it or not, DIODES !!

So they can be used on low voltage ( ie 6.3V ) AC supplies with only a
series resistor.


Yes. However, they are not renowned for having a very high PIV, so
whilst you would probably get away with just a series resistor at low
AC,


** Jesus ****ING CHRIST -

this IDIOT just DOES NOT READ !!!!!!!!!



No, it's YOU who either does not read,


** FFS - you REPEATED the info in MY post back to me !!!

You pompous, bull****ting, ****ing nut case.


Back at you on that one ! If *I'm* a nutcase, **** knows what that makes you
....





.... Phil


Give it up Philip. You should have learnt by now that you never end up
beating me down like you do most people, because I simply don't care what
you think or say about me. You behave on here like a total ****. Everybody -
not just me - thinks so, but you just don't see it do you ? You try to come
across as though you know everything about everything, and while sometimes
you appear to be quite clever when you've got your right head on, most of
the time, all you do is latch onto some irrelevant point and labour and
labour and labour it, getting ever more and more angry and stupid about it.
You are, quite simply, mentally ill, which is why most of the time, I'm
prepared to let you get on with it.

So, have you had enough yet, and ready to get back under your rock, or shall
I keep beating up on you ... ? :-)

Arfa

"Black Iccy" wrote in message
...
On Fri, 6 Sep 2013 01:31:39 +0100, "Arfa Daily"
wrote:

That aspect can be mitigated by
having a conventional diode in inverse parallel, but this will result in a
flicker at half the supply frequency that Phil can't see, but some of us
can, or by putting another LED in inverse parallel, which will conduct on
the opposite half cycle producing light, and clamping the reverse voltage
across the first diode to the value of the forward voltage of the second
diode, different, of course for different colours.

Surely, it will be at the _SAME_ frequency but exist as a light
source for only half the period (duty cycle). N'est-ce pas?


Each LED will flicker at half the supply frequency, but each will emit light
on opposite halves of the AC waveform. Thus, if the two LEDs are physically
close together, the flicker from each will be mitigated by the other.

Arfa

"Arfa ****WIT Daily"


** LEDs are, believe it or not, DIODES !!

So they can be used on low voltage ( ie 6.3V ) AC supplies with only a
series resistor.


Yes. However, they are not renowned for having a very high PIV, so
whilst you would probably get away with just a series resistor at low
AC,


** Jesus ****ING CHRIST -

this IDIOT just DOES NOT READ !!!!!!!!!


No, it's YOU who either does not read,


** FFS - you REPEATED the info in MY post back to me !!!

You pompous, bull****ting, ****ing nut case.




..... Phil

"Arfa ****wit Daily"
"Black Iccy"
"Arfa ****wit Daily"

That aspect can be mitigated by
having a conventional diode in inverse parallel, but this will result in
a
flicker at half the supply frequency that Phil can't see, but some of us
can, or by putting another LED in inverse parallel, which will conduct on
the opposite half cycle producing light, and clamping the reverse voltage
across the first diode to the value of the forward voltage of the second
diode, different, of course for different colours.

Surely, it will be at the _SAME_ frequency but exist as a light
source for only half the period (duty cycle). N'est-ce pas?


Each LED will flicker at half the supply frequency,


** FFS - wake up you IMBECILE !!!!!!!!!!

Half wave rectification = 50 /60 Hz ripple.

Full wave = 100 /120 Hz ripple.

Dead horses are lining up in drives right now ...



..... Phil

"Arfa Daily" wrote in message ...

You are, quite simply, mentally ill, which is why most of the time,
I'm prepared to let you get on with it.

One of the things I learned in screenwriting school was that it makes no sense
to tell stories about good versus evil -- specifically, stories about a
person's internal conflict over good and evil. The reason is that human beings
always think that whatever they do is good -- or at least, not wrong.

Regardless of /why/ Phil jumps so abruptly between Dr Jekyll and Mr Hyde, both
perspectives seem right /to him/. And no amount of rationality or arguing will
enable him to see any differently.

Similarly, when a person in another group who'd repeatedly abused me and
others, in the nastiest manner possible, said that he'd been only teasing
me -- and why didn't I take it in good humor? -- it became obvious that
(whether or not he's "disturbed") he could not step outside his perceptions
and recognize that his behavior was beyond the pale.

"William Sommerwerck"

Regardless of /why/ Phil jumps so abruptly between Dr Jekyll and Mr Hyde,

** No such thing is going on, at all.

AD is mentally defective, in about 5 ways at once.

He cannot be reasoned with as he is TOTALLY unaware of any of his defects.
He posts utter crap all the time and does not even read the corrections -
his bloated ego blinds him to the value of them.

Usenet is completely infested with people like AD, they cannot be persuaded
to leave and no amount of " outing " or verbal abuse has any effect.

In the real world, it is easy enough to avoid the likes of AD ( unless he is
your boss or teacher ) - but usenet provides no way of dealing with them.

Big mistake in how the scheme was first set up.

Apparently, Facebook and Twitter is not much better.



.... Phil

On Sat, 7 Sep 2013 02:50:22 +0100, "Arfa Daily"
wrote:

That aspect can be mitigated by
having a conventional diode in inverse parallel, but this will result in a
flicker at half the supply frequency that Phil can't see, but some of us
can, or by putting another LED in inverse parallel, which will conduct on
the opposite half cycle producing light, and clamping the reverse voltage
across the first diode to the value of the forward voltage of the second
diode, different, of course for different colours.

Surely, it will be at the _SAME_ frequency but exist as a light
source for only half the period (duty cycle). N'est-ce pas?


Each LED will flicker at half the supply frequency, but each will emit light
on opposite halves of the AC waveform. Thus, if the two LEDs are physically
close together, the flicker from each will be mitigated by the other.

Arfa


This whole argument is silly but, pardon me, that is NOT what you said Arfa
(thus my reason for jumping in) and you appear to be combining two distinct
posts.

Message-ID:

That said, if two LEDs are used in inverse parallel as you suggested, rather
than paralleling with a conventional diode or just relying on the reverse
blocking of the LED, flicker is not an issue, as each LED will produce light
on opposite half cycles.

If this (back-to-back) is done, the "flash" frequency (periodic rate if you
prefer) will be 100 times / sec. Correct? Two flashes per complete sine?
Still only 1 flash per each diode per full cycle of course but most certainly
flash pulsing will not be halved under any conditions. Doubled in fact.

And just for kickers, the forward conduction breakdown from each diode, in
turn, ought to be lower than the reverse destruction breakdown voltage, in my
experience anyway. Therefore a single dropping resistor would be effective.

But at a later post, Message-ID: in full...

Which is exactly what I said. If running them on AC, they are fine as long
as the series resistor is of sufficient value to limit the forward current,
and the reverse voltage on the opposite half cycle does not exceed the
rather low PIV that LEDs tend to have.
So far so good

That aspect can be mitigated by
having a conventional diode in inverse parallel, but this will result in a
flicker at half the supply frequency that Phil can't see, but some of us
can, or by putting another LED in inverse parallel, which will conduct on
the opposite half cycle producing light, and clamping the reverse voltage
across the first diode to the value of the forward voltage of the second
diode, different, of course for different colours.

Now what do you mean by that? Piggying a standard .6 V drop diode across
a dual, reversed set? That would circumvent 1 of the diodes getting a
sufficiently high forward voltage bias. In that case, we are back to half-wave
operation at the line frequency (whatever that may be). BUT, it (the flashes)
will never be at half the line frequency (which Phil defines as the repetition
rate).

OR do you mean having ...

Just a single LED with conduction in a particular direction but which is being
shunted by a reverse diode so that the LED's being protected from reverse
over-voltage? If so, then the same conditions as just outlined, still apply.

But, whichever viewpoint you deem more accurate/intended, indeed even if you
reject both, I repeat the section of your post for emphasis ....

That aspect can be mitigated by
having a conventional diode in inverse parallel, but this will result in a
flicker at half the supply frequency that Phil can't see, but some of us
^^^^^^^^^^^^^^^

No sir. Never *half* the supply frequency. That would mean 25 or 30 pulses/sec
for standard 50~ or 60~ supplies. Power might well not be consumed for the
full input cycle - a fact which we acknowledge by using the term 'duty factor'
or 'duty cycle'. Irrelevant what Phil sees -)

Reducing to absurdity: A simple transformer fed from a 50~ source with a
secondary output sufficient to produce forward conduction will produce 50
flashes/sec. Not half. Not 25. Now, if we'd full-wave rectified, we'd get 100
FPS from a single diode.
I'm outa here.

"Black Iccy"


And just for kickers, the forward conduction breakdown from each diode, in
turn, ought to be lower than the reverse destruction breakdown voltage, in
my
experience anyway. Therefore a single dropping resistor would be
effective.

** For interest sake, I checked a few 5mm white LEDs in stock for reverse
breakdown.

Each exceeded 21 volts with reverse current under 3uA ( maybe nothing)

Be fine with a 12.6V AC heater supply and ONE resistor.

There is NO flicker.


.... Phil

"Arfa Daily" wrote in message
...


"Trevor Wilson" wrote in message
...
On 4/09/2013 11:52 PM, Tim Schwartz wrote:
Hello all,

Anyone know of a generic lamp that is an 8 volt, 40 mA bipin type?
These are used as source indicators in receivers like the Marantz 2270
and 2275. The 6.3 volt 7380 is readily available, but won't last long
running on 8 volts, and gets too hot as well.

Of course a reliable vendor who sells them would be just as good.

Many thanks,
Tim Schwartz
Bristol Electronics

**I've found that owners of those old Marantz recievers are only too
happy to spend some extra bucks on replacing ALL lamps with LEDs. That
includes the stereo and source indicator lamps. The payoffs are huge.
They include:

* Far lower power consumption and consequent minimised damage to the
plastic housing that contains the dial back-lighting.
* Far, far more attractive dial lighting, if the LEDs used are blue ones.
* Indefinite (or at least very long) life-span for the lighting.

I've found that Lumileds™ work extremely well, due to their wide
dispersion characteristics. It requires some extra effort for the
repairer though. You can purchase plug-n-play replacements from eBay, if
you can't be bothered doing your own work.

--
Trevor Wilson www.rageaudio.com.au


Although of course, care needs to be taken that the lamps are actually
being fed with DC. In many items using pea bulb indicators and back
illumination, they are fed with AC straight off the tranny, or sometimes
via a series resistor whether AC or DC. This means that if you drop the
current by swapping to LEDs, the voltage will rise. I have also found that
it is hard to match the 'colour' of small bulbs with LEDs, particularly
when they are deliberately under-run to produce a more 'lemon' coloured
light. Things like tuning meters just don't look right if the light behind
them is too white. And even with wide angle LEDs, the light dispersion is
sometimes not enough to 'fill' an area with light, resulting in uneven
illumination.


Last time I ordered wide angle IRLEDS, what arrived had nearly flat lens
end - filing down has appeared in various forums recently, but last time I
tried that, I hit the bond wire!

Flattening the end a bit with a coarse abrasive also makes it a diffused
light source.

Cheapo headband lamps or 24 LED worklights are a good source of LEDs so
cheap you can afford to lose a few experimenting.

"Leif Neland" wrote in message
...
Phil Allison kom med følgende:
"Arfa Daily"

Although of course, care needs to be taken that the lamps are actually
being fed with DC.


** LEDs are, believe it or not, DIODES !!

Having LEDs run on one half-phase of AC can cause flicker.

More importantly, you have to protect it on the alternate half-cycles, the
series resistor doesn't usually drop enough voltage at the reverse leakage
current to protect the typically 5V PIV.

Either use the LEDs in inverse-parallel pairs, or protect each one with an
inverse-parallel 1N4148.

"Gareth Magennis" wrote in message
...

** For typical red bezels or indicator lights, it is simply not visible.


It is to some of us. I find the PWM'd LED flicker of road works cone-top
beacons very annoying, as well as the flicker from PWM'd LED stop and
tail lights on some makes of car. My wife doesn't notice it all, however.
Admittedly, the effect is worse at the periphery of vision, but I still
see it looking head on at the source.



Although I don't find this particularly annoying, I very much notice it
too.
For me the effect manifests itself as a line of bright strobing when my
eyes move horizontally past the flickering LED's. Like * * * * *
* * * * * * *

Inspired by novelty neon plug-caps, I once wired a PL type florescent tube
in series with the HT lead on a motorcycle, a cop gave me a really funny
look - but was too lazy to turn round and chase after me.

The ignition became unreliable about a month later so the experiment wasn't
repeated.

"Mike Tomlinson" wrote in message
...
En el artículo , Leif Neland
escribió:

The treatment could be botox at the vocal cords (would it help for
typing? Possibly in the hands instead) or brain surgery.

He'd have to have a brain in the first place to operate on.

And yet he still has more lucid moments than JF & JT put together!

"Phil Allison" wrote in message
...

"Black Iccy"


And just for kickers, the forward conduction breakdown from each diode,
in
turn, ought to be lower than the reverse destruction breakdown voltage,
in my
experience anyway. Therefore a single dropping resistor would be
effective.

** For interest sake, I checked a few 5mm white LEDs in stock for reverse
breakdown.

Each exceeded 21 volts with reverse current under 3uA ( maybe nothing)

You might have got away with dumping that much reverse voltage just the one
time, but continuous reverse half cycles probably puts their life expectancy
in the same ball park as filament bulbs!

It is to some of us. I find the PWM'd LED flicker of road works cone-top
beacons very annoying, as well as the flicker from PWM'd LED stop and tail
lights on some makes of car.




There's an app note here for a Stop/Tail IC.

http://www.maximintegrated.com/app-n...ex.mvp/id/4316
(It claims an operating frequency of 200 Hz, but this is not necessarily
what is currently out there)


Seems a bit Sledgehammer To Crack a Nut to me, but there you go.
My current Stop and Tail technology is 2 wires and a cheap easily
replaceable dual filament bulb.




Gareth.

"Phil Allison" wrote in message
...



**Except that is a REALLY dumb idea. The dial scale in the old Marantz
recievers is blue.

Maybe, maybe not. If I had one in my inventory/junque box, I would
consider it a cheeap expeeriment and give it a try. If I could get one
for about a dollar, I would consider taking a chance.

** Wide angle, 5mm blue LEDs sell for about $1.00 each.

The correct 8V bi-pin lamps will cost you more.

You will need one resistor ( 470 ohms to 1kohms) for each LED and just
ignore the insane crap here from AD etc about visible flicker at 60Hz.

If there is (or you perceive) any flicker, just wire a bead tantalum across
each LED - just make sure there is *NO* reverse current.

"Ian Field = Fool"
Phil Allison

** LEDs are, believe it or not, DIODES !!

Having LEDs run on one half-phase of AC can cause flicker.

More importantly, you have to protect it on the alternate half-cycles, the
series resistor doesn't usually drop enough voltage at the reverse leakage
current to protect the typically 5V PIV.


** The spec of 5V is a nonsense.

Red LEDs take at least 9V reverse before any current flowed.

The white ones I have in stock took 22V with no current.



.... Phil

Gareth Magennis formulerede Sunday:
It is to some of us. I find the PWM'd LED flicker of road works cone-top
beacons very annoying, as well as the flicker from PWM'd LED stop and tail
lights on some makes of car.




There's an app note here for a Stop/Tail IC.

http://www.maximintegrated.com/app-n...ex.mvp/id/4316
(It claims an operating frequency of 200 Hz, but this is not necessarily what
is currently out there)


Seems a bit Sledgehammer To Crack a Nut to me, but there you go.
My current Stop and Tail technology is 2 wires and a cheap easily replaceable
dual filament bulb.


Which uses more energy, and breaks several times more often than LED.
Many drivers seems to lazy to check or fix their taillights.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

"Phil Allison" wrote in message
...

"Ian Field = Fool"
Phil Allison

** LEDs are, believe it or not, DIODES !!

Having LEDs run on one half-phase of AC can cause flicker.

More importantly, you have to protect it on the alternate half-cycles,
the series resistor doesn't usually drop enough voltage at the reverse
leakage current to protect the typically 5V PIV.


** The spec of 5V is a nonsense.

Red LEDs take at least 9V reverse before any current flowed.

The white ones I have in stock took 22V with no current.

Getting away with a single static test is one thing - continuous repetitive
negative half-cycles might have a more tangible effect on LED life
expectancy.

On Monday, September 9, 2013 11:07:02 AM UTC-4, Ian Field wrote:
"Phil Allison" wrote in message

...



"Ian Field = Fool"

Phil Allison



** LEDs are, believe it or not, DIODES !!



Having LEDs run on one half-phase of AC can cause flicker.



More importantly, you have to protect it on the alternate half-cycles,

the series resistor doesn't usually drop enough voltage at the reverse

leakage current to protect the typically 5V PIV.





** The spec of 5V is a nonsense.

Red LEDs take at least 9V reverse before any current flowed.

The white ones I have in stock took 22V with no current.

Getting away with a single static test is one thing - continuous repetitive
negative half-cycles might have a more tangible effect on LED life
expectancy.

Gotta agree with Phil, The 5V spec is nonsense. I haven't found an LEDs that (reverse bias) avalanche at any voltage less than 20V. If no current flows then what damage is done?

Phil, do you perhaps know the part number of the red LED that could only take 9V of reverse bias? I'd like to order some.

Oh.. most of the LED's I looked at took over 100 V of reverse bias till they avalanched.

George H.

Ian Field wrote:

"Mike Tomlinson" wrote in message
...
En el artículo , Leif Neland
escribió:

The treatment could be botox at the vocal cords (would it help for
typing? Possibly in the hands instead) or brain surgery.

He'd have to have a brain in the first place to operate on.

And yet he still has more lucid moments than JF & JT put together!


Still trying to put them down, and I doubt either read the group when
it isn't cross posted to SED.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

** The spec of 5V is a nonsense.

Red LEDs take at least 9V reverse before any current flowed.

The white ones I have in stock took 22V with no current.

Getting away with a single static test is one thing - continuous
repetitive
negative half-cycles might have a more tangible effect on LED life
expectancy.

Gotta agree with Phil, The 5V spec is nonsense.
I haven't found an LEDs that (reverse bias) avalanche at any voltage
less than 20V. If no current flows then what damage is done?

Phil, do you perhaps know the part number of the red LED that could only
take 9V of reverse bias?

Oh.. most of the LED's I looked at took over 100 V of reverse bias till
they avalanched.


** Just checked a bin of assorted LEDs for breakdown voltage with a test
current of around 10uA.

The lowest was 30V and the highest was 157V - both red LEDs.

A blue LED was 21V.

Two white LEDs were 42 and 61V

LEDs of the exact same type show similar figures, but the variation between
types is large.


.... Phil

Phil Allison tastede følgende:

** Just checked a bin of assorted LEDs for breakdown voltage with a test
current of around 10uA.

The lowest was 30V and the highest was 157V - both red LEDs.

A blue LED was 21V.

Two white LEDs were 42 and 61V

LEDs of the exact same type show similar figures, but the variation between
types is large.


Beancounting:

If the variation is large, if X percent of the LEDs have a breakdown
voltage below the one in the circuit, a reverse diode cost Y, the
repair cost is Z, collateral damage is P, damage to reputation is Q, do
you pur a reverse diode in?

Perhapes forward voltage is a median, but if reverse breakdown is
fatal, it is the 0.001 percentile or something.

"Don't exceed this voltage, one in ... might break". Don't want it to
be the gear down indicator on your next flight.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

"Leif Neland"


** Wot is WRONG with this wog idiot ??


** Just checked a bin of assorted LEDs for breakdown voltage with a test
current of around 10uA.

The lowest was 30V and the highest was 157V - both red LEDs.

A blue LED was 21V.

Two white LEDs were 42 and 61V

LEDs of the exact same type show similar figures, but the variation
between types is large.


If the variation is large,


** But the threshold is at least 30V for any red, green or amber LED !!!!!!

Generally much higher and easy to test.

if X percent of the LEDs have a breakdown voltage below the one in the
circuit,


** The application is replacing 6V and 12V lamps that run from AC.

****wit .


..... Phil

Phil Allison har bragt dette til os:


****wit .


.... Phil

Your title should go below your name, not above.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

"Leif Neland"


****wit.


Your title should go below your name,


** Your mother needs shooting.

What a vile piece of know nothing, autistic scum you are.

Get off this newsgroup for ever.




.... Phil

On Thursday, September 12, 2013 12:03:52 AM UTC-4, Phil Allison wrote:




** The spec of 5V is a nonsense.



Red LEDs take at least 9V reverse before any current flowed.



The white ones I have in stock took 22V with no current.



Getting away with a single static test is one thing - continuous

repetitive

negative half-cycles might have a more tangible effect on LED life

expectancy.



Gotta agree with Phil, The 5V spec is nonsense.

I haven't found an LEDs that (reverse bias) avalanche at any voltage

less than 20V. If no current flows then what damage is done?

Phil, do you perhaps know the part number of the red LED that could only

take 9V of reverse bias?

Oh.. most of the LED's I looked at took over 100 V of reverse bias till

they avalanched.

** Just checked a bin of assorted LEDs for breakdown voltage with a test

current of around 10uA.
The lowest was 30V and the highest was 157V - both red LEDs.
A blue LED was 21V.

Two white LEDs were 42 and 61V

LEDs of the exact same type show similar figures, but the variation between

types is large.

Grin.. yeah large variation. We're using these red led's (AND114R) as reverse biased photo detectors. Vbreak ~25 volts. The same company makes a similar led.. same material, same wavelength (AND113R) a bit more light. It's breakdown voltage is ~120 V.

Thanks for the measurements.

George H.





... Phil

On Thursday, September 12, 2013 12:57:00 AM UTC-4, Leif Neland wrote:
Phil Allison tastede følgende:



** Just checked a bin of assorted LEDs for breakdown voltage with a test

current of around 10uA.



The lowest was 30V and the highest was 157V - both red LEDs.



A blue LED was 21V.



Two white LEDs were 42 and 61V



LEDs of the exact same type show similar figures, but the variation between

types is large.





Beancounting:



If the variation is large, if X percent of the LEDs have a breakdown

voltage below the one in the circuit, a reverse diode cost Y, the

repair cost is Z, collateral damage is P, damage to reputation is Q, do

you pur a reverse diode in?



Perhapes forward voltage is a median, but if reverse breakdown is

fatal, it is the 0.001 percentile or something.



"Don't exceed this voltage, one in ... might break". Don't want it to

be the gear down indicator on your next flight.


Huh? If it's critical just put another LED or diode back to back in parallel. (I wonder if someone already makes such a device.)

George H.


Leif



--

Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske

beslutning at undlade det.

"Michael A. Terrell" wrote in message
m...

Ian Field wrote:

"Mike Tomlinson" wrote in message
...
En el artículo , Leif Neland
escribió:

The treatment could be botox at the vocal cords (would it help for
typing? Possibly in the hands instead) or brain surgery.

He'd have to have a brain in the first place to operate on.

And yet he still has more lucid moments than JF & JT put together!


Still trying to put them down, and I doubt either read the group when
it isn't cross posted to SED.

Having KF'd JF months ago, I only see his insane ranting when someone else
replies to him - JT is becoming increasingly comedic, great stuff for a good
belly-laugh.

"Phil Allison" wrote in message
...

"Leif Neland"


** Wot is WRONG with this wog idiot ??


** Just checked a bin of assorted LEDs for breakdown voltage with a
test current of around 10uA.

The lowest was 30V and the highest was 157V - both red LEDs.

A blue LED was 21V.

Two white LEDs were 42 and 61V

LEDs of the exact same type show similar figures, but the variation
between types is large.


If the variation is large,


** But the threshold is at least 30V for any red, green or amber LED
!!!!!!

Generally much higher and easy to test.

if X percent of the LEDs have a breakdown voltage below the one in the
circuit,


** The application is replacing 6V and 12V lamps that run from AC.

It still exceeds what the manufacturer *GUARANTEES* that the part can
withstand.

If you want to take a chance running the part out of spec, that's your
choice.

wrote in message
...
On Thursday, September 12, 2013 12:57:00 AM UTC-4, Leif Neland wrote:
Phil Allison tastede følgende:



** Just checked a bin of assorted LEDs for breakdown voltage with a
test

current of around 10uA.



The lowest was 30V and the highest was 157V - both red LEDs.



A blue LED was 21V.



Two white LEDs were 42 and 61V



LEDs of the exact same type show similar figures, but the variation
between

types is large.





Beancounting:



If the variation is large, if X percent of the LEDs have a breakdown

voltage below the one in the circuit, a reverse diode cost Y, the

repair cost is Z, collateral damage is P, damage to reputation is Q, do

you pur a reverse diode in?



Perhapes forward voltage is a median, but if reverse breakdown is

fatal, it is the 0.001 percentile or something.



"Don't exceed this voltage, one in ... might break". Don't want it to

be the gear down indicator on your next flight.


Huh? If it's critical just put another LED or diode back to back in
parallel. (I wonder if someone already makes such a device.)

2-pin bi-colour LEDs exist - but the end result won't be either red nor
green.

Ian Field udtrykte præcist:

wrote in message
...
On Thursday, September 12, 2013 12:57:00 AM UTC-4, Leif Neland wrote:
Phil Allison tastede følgende:



** Just checked a bin of assorted LEDs for breakdown voltage with a
test

current of around 10uA.



The lowest was 30V and the highest was 157V - both red LEDs.



A blue LED was 21V.



Two white LEDs were 42 and 61V



LEDs of the exact same type show similar figures, but the variation
between

types is large.





Beancounting:



If the variation is large, if X percent of the LEDs have a breakdown

voltage below the one in the circuit, a reverse diode cost Y, the

repair cost is Z, collateral damage is P, damage to reputation is Q, do

you pur a reverse diode in?



Perhapes forward voltage is a median, but if reverse breakdown is

fatal, it is the 0.001 percentile or something.



"Don't exceed this voltage, one in ... might break". Don't want it to

be the gear down indicator on your next flight.


Huh? If it's critical just put another LED or diode back to back in
parallel. (I wonder if someone already makes such a device.)

Yes, that is my point.

2-pin bi-colour LEDs exist - but the end result won't be either red nor
green.

Here's some old news: http://ledsmagazine.com/news/3/11/14
One half of the led lights in the positive half-cycle, the other half
in the other half-cycle.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

Phil Allison tastede følgende:
"Black Iccy"


And just for kickers, the forward conduction breakdown from each diode, in
turn, ought to be lower than the reverse destruction breakdown voltage, in
my
experience anyway. Therefore a single dropping resistor would be effective.

** For interest sake, I checked a few 5mm white LEDs in stock for reverse
breakdown.

Each exceeded 21 volts with reverse current under 3uA ( maybe nothing)

Be fine with a 12.6V AC heater supply and ONE resistor.


It would be interesting to test this:

12V AC, one led with a dropping resistor, giving say 10mA.
Another led, with a diode in reverse, same size dropping resistor.

24V AC, similar circuits. (dropping resistor having the proper larger
value)

Run for a a couple of months, or until a led fails.

I bet it will be the one at 24V without diode in reverse.

Leif


--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.

"Leif Neland"


** **** off RETARDED TROLL !!!!!!!!!!

Ian Field wrote:

"Michael A. Terrell" wrote in message
m...

Ian Field wrote:

"Mike Tomlinson" wrote in message
...
En el artículo , Leif Neland
escribió:

The treatment could be botox at the vocal cords (would it help for
typing? Possibly in the hands instead) or brain surgery.

He'd have to have a brain in the first place to operate on.

And yet he still has more lucid moments than JF & JT put together!


Still trying to put them down, and I doubt either read the group when
it isn't cross posted to SED.

Having KF'd JF months ago, I only see his insane ranting when someone else
replies to him - JT is becoming increasingly comedic, great stuff for a good
belly-laugh.


You're the joke, but like Phil, you don't see it. All you two want to
do is stir up ****, then wallow in it.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.