Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.


PS If anyone is interested, I can Email you
the schematic.....

Andy wrote in news:23d7405e-fe98-48eb-9a60-
:

Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.


PS If anyone is interested, I can Email you
the schematic.....

Can't find a link for the darn luminescent night light we have had going
for more than 20 years. It is a 2" diameter flat disc in a very thin
housing that glows blueish/tealish at night. The info on it is
Intermatic Inc, GN GOOD NITE LITE, E 187141, Model GN141, UL listed 8G25
and ML-003, Made in Taiwan.


--
Best regards
Han
email address is invalid

On Sep 18, 9:55 am, Han wrote:

Can't find a link for the darn luminescent night light we have had going
for more than 20 years. It is a 2" diameter flat disc in a very thin
housing that glows blueish/tealish at night. The info on it is
Intermatic Inc, GN GOOD NITE LITE, E 187141, Model GN141, UL listed 8G25
and ML-003, Made in Taiwan.

--
Best regards
Han
email address is invalid

Andy comments,

Han, I have seen those electroluminscent lights... The blue LED
puts out a lot more light.... If you like your electros, you would
LOVE the blue LEDs..... I don't know the power your electro uses,
but I'm sure it is quite small.... I have used that technology for
backlighting displays in the past..... I found that they are great
for marking a place on the wall, but don't put a lot of light out
into the room to avoid stepping on the grandaughter's roller skate
in the middle of the hallway... ....
:)))))

Thanks for the reply.

Andy in Eureka , P.E.

Andy wrote in
:

On Sep 18, 9:55 am, Han wrote:

Can't find a link for the darn luminescent night light we have had
going for more than 20 years. It is a 2" diameter flat disc in a
very thin housing that glows blueish/tealish at night. The info on
it is Intermatic Inc, GN GOOD NITE LITE, E 187141, Model GN141, UL
listed 8G25 and ML-003, Made in Taiwan.

--
Best regards
Han
email address is invalid

Andy comments,

Han, I have seen those electroluminscent lights... The blue LED
puts out a lot more light.... If you like your electros, you would
LOVE the blue LEDs..... I don't know the power your electro uses,
but I'm sure it is quite small.... I have used that technology for
backlighting displays in the past..... I found that they are great
for marking a place on the wall, but don't put a lot of light out
into the room to avoid stepping on the grandaughter's roller skate
in the middle of the hallway... ....
:)))))

Thanks for the reply.

Andy in Eureka , P.E.

You're welcome, Andy. We just use it to reference the toiletseat ....


--
Best regards
Han
email address is invalid

Han writes:

You're welcome, Andy. We just use it to reference the toiletseat ....

Hmm, did I just hear BLUE LED TOILET SEAT?

Hot damn:

http://www.kiss-textil.de/galactikaen.htm

--
Dan Espen

On Sep 18, 5:19 pm, wrote:
Han writes:
You're welcome, Andy. We just use it to reference the toiletseat ....

Hmm, did I just hear BLUE LED TOILET SEAT?

Hot damn:

http://www.kiss-textil.de/galactikaen.htm

--
Dan Espen

Andy comments;

Des, I'm pretty sure that Han's wife made him put the light in
so he could have better aim at night, and not wake her up
by turning on the bathroom light......

Been there, done that... :)))))

Andy in Eureka, Texas

On 9/18/2011 10:55 AM, Han wrote:
wrote in news:23d7405e-fe98-48eb-9a60-
:

Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.


PS If anyone is interested, I can Email you
the schematic.....

Can't find a link for the darn luminescent night light we have had going
for more than 20 years. It is a 2" diameter flat disc in a very thin
housing that glows blueish/tealish at night. The info on it is
Intermatic Inc, GN GOOD NITE LITE, E 187141, Model GN141, UL listed 8G25
and ML-003, Made in Taiwan.


You had much better luck than me. We had at least 4 different versions
of the type of night light you described. All slowly burned out block by
block. I replaced them with the LED versions.

George wrote in :

You had much better luck than me. We had at least 4 different versions
of the type of night light you described. All slowly burned out block by
block. I replaced them with the LED versions.

This thing has been in constant use for at least 20 years. LEDs didn't
exist,at least not publicly available, when we bought them (another one is
still in storage somewhere).

--
Best regards
Han
email address is invalid

On 9/18/2011 1:55 PM, Han wrote:
wrote in :

You had much better luck than me. We had at least 4 different versions
of the type of night light you described. All slowly burned out block by
block. I replaced them with the LED versions.

This thing has been in constant use for at least 20 years. LEDs didn't
exist,at least not publicly available, when we bought them (another one is
still in storage somewhere).


Not claiming you should have bought LED versions back then just
mentioning that I saw poor results with the devices you mentioned. And
come to think of it they are gone from the various other places I have
seen them being used.

Yours seems to be a lot like that light bulb in the NYC firehouse that
has been burning for the last 89 years (or whatever).

Andy wrote:
Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.


PS If anyone is interested, I can Email you
the schematic.....
Hi,
Limiting by series capacitor?
Prices of those will come down further with time for sure.

On Sep 18, 10:35*am, Tony Hwang wrote:
Andy wrote:
Andy writes:
* * *I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) *and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

* * * They are advertised to draw only *0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) *. * I kind of like that...

* * * So I took one apart and made a schematic. * The
limiting is done by a series capacitor.... *I then fed the
network into a PSPICE simulator and checked out the
claim..... *Truly, it uses only 0.4 watts of real power.....

* * *I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

* * *Sure, the *light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

* * * * * * * *Andy in Eureka, * P.E.

PS * If anyone is *interested, I can *Email you
* * * * *the schematic.....

Hi,
Limiting by series capacitor?
Prices of those will come down further with time for sure.- Hide quoted text -

- Show quoted text -

A small capacitor will have a very high resistance (Impedance) at 60
Hz, so it is effective. The LED probably only needs about 50 - 100
milliamperes, and no power is lost in the capacitor, so everything
works great.

On Sun, 18 Sep 2011 08:47:09 -0700 (PDT), "hr(bob) "
wrote:

On Sep 18, 10:35*am, Tony Hwang wrote:
Andy wrote:
Andy writes:
* * *I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) *and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

* * * They are advertised to draw only *0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) *. * I kind of like that...

* * * So I took one apart and made a schematic. * The
limiting is done by a series capacitor.... *I then fed the
network into a PSPICE simulator and checked out the
claim..... *Truly, it uses only 0.4 watts of real power.....

* * *I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

* * *Sure, the *light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

* * * * * * * *Andy in Eureka, * P.E.

PS * If anyone is *interested, I can *Email you
* * * * *the schematic.....

Hi,
Limiting by series capacitor?
Prices of those will come down further with time for sure.- Hide quoted text -

- Show quoted text -

A small capacitor will have a very high resistance (Impedance) at 60
Hz, so it is effective. The LED probably only needs about 50 - 100
milliamperes, and no power is lost in the capacitor, so everything
works great.

100mA would be about .3-.4W dissipated by the diode (Vf=3-4V @100mA), so
you're in the ballpark.

On Sep 18, 11:03 am, "
wrote:


100mA would be about .3-.4W dissipated by the diode (Vf=3-4V @100mA), so
you're in the ballpark.

Andy comments:

Yeah.. It seems that the power factor shift ( around 80 deg from
memory,
but don't hold me to it ) means that the power is reactive, and
doesn't
register on the TXU meter..... That's how I figured it ...

Andy in Eureka, PE

On Sep 18, 10:47 am, "hr(bob) "
wrote:
On Sep 18, 10:35 am, Tony Hwang wrote:



Andy wrote:
Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.

PS If anyone is interested, I can Email you
the schematic.....

Hi,
Limiting by series capacitor?
Prices of those will come down further with time for sure.- Hide quoted text -

- Show quoted text -

A small capacitor will have a very high resistance (Impedance) at 60
Hz, so it is effective. The LED probably only needs about 50 - 100
milliamperes, and no power is lost in the capacitor, so everything
works great.

Andy comments:

A privelege to hear from someone who understands the subject ...

Andy in Eureka, P.E.

On Sep 18, 10:47 am, "hr(bob) "
wrote:
On Sep 18, 10:35 am, Tony Hwang wrote:



Andy wrote:
Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.

PS If anyone is interested, I can Email you
the schematic.....

Hi,
Limiting by series capacitor?
Prices of those will come down further with time for sure.- Hide quoted text -

- Show quoted text -

A small capacitor will have a very high resistance (Impedance) at 60
Hz, so it is effective. The LED probably only needs about 50 - 100
milliamperes, and no power is lost in the capacitor, so everything
works great.

Andy comments:

PSPICE says around 20 ma peak.......(from memory) and the
powerfactor around 80% or so ( also from memory)

Run it youownself to check...... regular PSPICE ....

If you can buy one and dismantle it, it is very easy....
Or, send me an email address and I'll send you a schematic file....

Andy in Eureka, P.E.

On Sep 18, 10:35 am, Tony Hwang wrote:

Hi,
Limiting by series capacitor?
Prices of those will come down further with time for sure.


Andy comments:

I appreciate the fact that you know what I am talking about, but
if you add up the parts in the $1 USD nitelight, I really don't
see how it can be manufactured/distributed/retail markup
much cheaper....... I don't mind $1 USD ....... :)))


Andy in Eureka, P.E.

On Sun, 18 Sep 2011 07:39:52 -0700 (PDT), Andy
wrote:

Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

I've been using them (well, not from the dollar store) for three years. I
like them a lot. I have other colors, too.

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.


PS If anyone is interested, I can Email you
the schematic.....

Sure.

On Sep 18, 10:49 am, "
wrote:
On Sun, 18 Sep 2011 07:39:52 -0700 (PDT), Andy
wrote:



Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

I've been using them (well, not from the dollar store) for three years. I
like them a lot. I have other colors, too.

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.

PS If anyone is interested, I can Email you
the schematic.....

Sure.

Andy replies:
The "reply to author" in my browser gives crap for your Email....
So, I can send it to you in a PSPICE schematics file, or I'll
write out a "descriptive" file in .txt for you to use.. But I need
to know where to send it ...

Andy in Eureka, P.E.

On Sun, 18 Sep 2011 09:40:05 -0700 (PDT), Andy
wrote:

On Sep 18, 10:49 am, "
wrote:
On Sun, 18 Sep 2011 07:39:52 -0700 (PDT), Andy
wrote:



Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

I've been using them (well, not from the dollar store) for three years. I
like them a lot. I have other colors, too.

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.

PS If anyone is interested, I can Email you
the schematic.....

Sure.

Andy replies:
The "reply to author" in my browser gives crap for your Email....

Delete all but one of the trailing 'z's (krw at att dot biz).

So, I can send it to you in a PSPICE schematics file, or I'll
write out a "descriptive" file in .txt for you to use.. But I need
to know where to send it ...

Don't have PSPICE but it might work in LTSPICE.

Andy wrote:

I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each )

They are advertised to draw only 0.4 watts ...

Your typical high-brightness white LED can be powered to full brightness
by applying about 3.0 volts and maybe 25 milli-amps max. That works out
to 0.075 watts. You can buy high-brightness white LED's from Digikey
for anywhere from 10 to 25 cents each.

I don't know why or how your blue LED would draw 400 milliwatts. That's
crazy, unless there are 4 or 5 LED's in each unit.

You should just go with the cheap white LED's. They give off a more
natural light vs those blue ones.

On Sep 18, 12:12 pm, Home Guy wrote:

Your typical high-brightness white LED can be powered to full brightness
by applying about 3.0 volts and maybe 25 milli-amps max. That works out
to 0.075 watts. You can buy high-brightness white LED's from Digikey
for anywhere from 10 to 25 cents each.

I don't know why or how your blue LED would draw 400 milliwatts. That's
crazy, unless there are 4 or 5 LED's in each unit.

You should just go with the cheap white LED's. They give off a more
natural light vs those blue ones.

Andy comments:

There's other stuff in the blue LED lamp that makes it work only
on
the half cycle (there's maybe 50%), and a couple current limiting
resistors
also.... That's why the total power is so high... It is designed
with
some internal protection against transients that are always active.

Yes, I agree completely that the white versions are preferable from
a "light output" standpoint. If they become available, for a buck,
I'll
buy them instead.... Actually. the next time I'm at TANNER in
Dallas, I'll buy a high output white and substitute it and see how
it works.... Thanks for the suggestion...

Andy in Eureka, P.E.

Andy wrote:

You should just go with the cheap white LED's. They give off a
more natural light vs those blue ones.

Andy comments:

There's other stuff in the blue LED lamp that makes it work only
on the half cycle (there's maybe 50%), and a couple current
limiting resistors also....

Here's a page showing a few circuits for powering one or two LED's
directly from 120 Vac power line.

http://www.qsl.net/yo5ofh/hobby%20ci...d_circuits.htm

Plus lots of other LED circuits that remind me when I was building stuff
like this on a breadboard back in junior high.

But yes, it seems common to use a capacitor and resistor in series, as
well as as diode across the LED:

==========
Using a capacitor to drop the voltage and a small resistor to limit the
inrush current. Since the capacitor must pass current in both
directions, a small diode is connected in parallel with the LED to
provide a path for the negative half cycle and also to limit the reverse
voltage across the LED. A second LED with the polarity reversed may be
subsituted for the diode, or a tri-color LED could be used which would
appear orange with alternating current.

The circuit is fairly efficient and draws only about a half watt from
the line. The resistor value (1K / half watt) was chosen to limit the
worst case inrush current to about 150 mA which will drop to less than
30 mA in a millisecond as the capacitor charges. This appears be a safe
value, I have switched the circuit on and off many times without damage
to the LED.

The 0.47 uF capacitor has a reactance of 5600 ohms at 60 cycles so the
LED current is about 20 mA half wave, or 10 mA average. A larger
capacitor will increase the current and a smaller one will reduce it.
The capacitor must be a non-polarized type with a voltage rating of 200
volts or more.
===========

Andy replies:
Thanks for the website -- I'll bookmark it in my circuits folder..

The first circuit shown under AC Circuits is similar to the
light I'm talking about, except a 470K resistor is added across
the capacitor, apparently to make sure the circuit doesn't hold
a charge to surprise someone when it is unplugged....

In a reply to krw@att today, I posted a nodelist. Very simple.

I really like your idea about adding a second LED to replace the
reverse diode..... The units I have are simple to disassemble and
modify, and I'll probably try it out ..

Andy in Eureka, Texas P.E.

On 9/18/2011 1:24 PM, Andy wrote:
On Sep 18, 12:12 pm, Home wrote:

Your typical high-brightness white LED can be powered to full brightness
by applying about 3.0 volts and maybe 25 milli-amps max. That works out
to 0.075 watts. You can buy high-brightness white LED's from Digikey
for anywhere from 10 to 25 cents each.

I don't know why or how your blue LED would draw 400 milliwatts. That's
crazy, unless there are 4 or 5 LED's in each unit.

You should just go with the cheap white LED's. They give off a more
natural light vs those blue ones.

Andy comments:

There's other stuff in the blue LED lamp that makes it work only
on
the half cycle (there's maybe 50%), and a couple current limiting
resistors
also.... That's why the total power is so high... It is designed
with
some internal protection against transients that are always active.

Yes, I agree completely that the white versions are preferable from
a "light output" standpoint. If they become available, for a buck,
I'll
buy them instead.... Actually. the next time I'm at TANNER in
Dallas, I'll buy a high output white and substitute it and see how
it works.... Thanks for the suggestion...

Andy in Eureka, P.E.


Arrgh- accidently clicked the wrong 'reply to' line- thought I finally
had the hang of this new version of Tbird.


IMHO, the further you get from white light, the better. In addition to
night vision issues, white light, especially if it is close to the parts
of the daylight spectrum humans can see, kicks off the 'it's morning-
get up' algorithm in the brain. When I get the middle-of-the-night
hydraulic pressure alarms, I avoid turning on any white lights, and find
it MUCH easier to get back to sleep. Between all the equipment LEDs and
digital clocks scattered around the house, and ancient orange neon night
lights in each bath, the only thing I have to watch out for is the
refrigerator light, if I need a swig of something for cotton mouth, or
to wash down a sinus pill. (the OTHER thing that often wakes me up at
night.) I shut my eyes and avert my head, and find the jug in the door
mainly by feel.

--
aem sends...

On Sep 18, 5:22 pm, aemeijers wrote:
On 9/18/2011 1:24 PM, Andy wrote:



On Sep 18, 12:12 pm, Home wrote:

Your typical high-brightness white LED can be powered to full brightness
by applying about 3.0 volts and maybe 25 milli-amps max. That works out
to 0.075 watts. You can buy high-brightness white LED's from Digikey
for anywhere from 10 to 25 cents each.

I don't know why or how your blue LED would draw 400 milliwatts. That's
crazy, unless there are 4 or 5 LED's in each unit.

You should just go with the cheap white LED's. They give off a more
natural light vs those blue ones.

Andy comments:

There's other stuff in the blue LED lamp that makes it work only
on
the half cycle (there's maybe 50%), and a couple current limiting
resistors
also.... That's why the total power is so high... It is designed
with
some internal protection against transients that are always active.

Yes, I agree completely that the white versions are preferable from
a "light output" standpoint. If they become available, for a buck,
I'll
buy them instead.... Actually. the next time I'm at TANNER in
Dallas, I'll buy a high output white and substitute it and see how
it works.... Thanks for the suggestion...

Andy in Eureka, P.E.

Arrgh- accidently clicked the wrong 'reply to' line- thought I finally
had the hang of this new version of Tbird.

IMHO, the further you get from white light, the better. In addition to
night vision issues, white light, especially if it is close to the parts
of the daylight spectrum humans can see, kicks off the 'it's morning-
get up' algorithm in the brain. When I get the middle-of-the-night
hydraulic pressure alarms, I avoid turning on any white lights, and find
it MUCH easier to get back to sleep. Between all the equipment LEDs and
digital clocks scattered around the house, and ancient orange neon night
lights in each bath, the only thing I have to watch out for is the
refrigerator light, if I need a swig of something for cotton mouth, or
to wash down a sinus pill. (the OTHER thing that often wakes me up at
night.) I shut my eyes and avert my head, and find the jug in the door
mainly by feel.

--
aem sends...

Andy comments
I can't disagree.... PLUS, the erie blue glow is F.... G Cool !!!!!

Andy in Eureka

Home Guy wrote in :

Andy wrote:

I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each )

They are advertised to draw only 0.4 watts ...

Your typical high-brightness white LED can be powered to full brightness
by applying about 3.0 volts and maybe 25 milli-amps max. That works out
to 0.075 watts. You can buy high-brightness white LED's from Digikey
for anywhere from 10 to 25 cents each.

I don't know why or how your blue LED would draw 400 milliwatts. That's
crazy, unless there are 4 or 5 LED's in each unit.


no,whatever is dropping the **170V** peak-rectified line V to 3.5V is
what's consuming the extra power.You have to consider the TOTAL V-drops for
power consumed.

170 x .025 = 4.25W.

You should just go with the cheap white LED's. They give off a more
natural light vs those blue ones.


A "white" LED is just a blue LED with phosphors on top of the die,the blue
LED(also emits UV) energizes the phosphors to give off a "white" light.
that's why they appear yellow when off. That's the phosphors you see.

that's why both blue and "white" LEDs have the same V-drop;around 3.5V.

--
Jim Yanik
jyanik
at
localnet
dot com

On 9/18/2011 2:19 PM, Jim Yanik wrote:
Home wrote in :

Andy wrote:

I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each )

They are advertised to draw only 0.4 watts ...

Your typical high-brightness white LED can be powered to full brightness
by applying about 3.0 volts and maybe 25 milli-amps max. That works out
to 0.075 watts. You can buy high-brightness white LED's from Digikey
for anywhere from 10 to 25 cents each.

I don't know why or how your blue LED would draw 400 milliwatts. That's
crazy, unless there are 4 or 5 LED's in each unit.


no,whatever is dropping the **170V** peak-rectified line V to 3.5V is
what's consuming the extra power.You have to consider the TOTAL V-drops for
power consumed.


That would be true if the "whatever" were purely resistive. But this is
"more complex...". Capacitive reactance is involved. That causes a
phase shift between the voltage and current (voltage lags behind
current) which lowers the instantaneous power.


170 x .025 = 4.25W.

You should just go with the cheap white LED's. They give off a more
natural light vs those blue ones.


A "white" LED is just a blue LED with phosphors on top of the die,the blue
LED(also emits UV) energizes the phosphors to give off a "white" light.
that's why they appear yellow when off. That's the phosphors you see.

that's why both blue and "white" LEDs have the same V-drop;around 3.5V.

On Sep 18, 1:47 pm, George wrote:

That would be true if the "whatever" were purely resistive. But this is
"more complex...". Capacitive reactance is involved. That causes a
phase shift between the voltage and current (voltage lags behind
current) which lowers the instantaneous power.

Andy injects:

In the blue LED nitelite that I have, it is a 0.33 uf capacitor.....
The LED had a diode across it in the other direction to keep
the cap from charging up on the half cycle. A couple of
resistors for inrush limiting and cap leakage... That's it...

On Sun, 18 Sep 2011 14:57:25 -0700 (PDT), Andy
wrote:

On Sep 18, 1:47 pm, George wrote:

That would be true if the "whatever" were purely resistive. But this is
"more complex...". Capacitive reactance is involved. That causes a
phase shift between the voltage and current (voltage lags behind
current) which lowers the instantaneous power.

Andy injects:

In the blue LED nitelite that I have, it is a 0.33 uf capacitor.....
The LED had a diode across it in the other direction to keep
the cap from charging up on the half cycle. A couple of
resistors for inrush limiting and cap leakage... That's it...

The anti-parallel diode keeps the LED from becoming LED vapor when the current
in the other direction. ;-)

Andy wrote:

Andy writes:

You don't have to type your own name...

I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each )

That sounds about right.


and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

Sweet.

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

Awesome man.

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

You must be retired, you have w-a-y too much time on your hands.

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

You want feedback on $1 nightlights?

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

It sounds like a creepy household!

Andy in Eureka,

Which one?

Eureka, California
Eureka, Colorado
Eureka, Nevada County, California
Eureka, Illinois
Eureka, Indiana
Eureka, Florida
Eureka, Kansas
Eureka, Louisiana
Eureka, Missouri
Eureka, Montana
Eureka, Nevada
Eureka, North Carolina
Eureka, South Dakota
Eureka, Texas
Eureka, Utah
Eureka, Polk County, Wisconsin, a town
Eureka, Winnebago County, Wisconsin, an unincorporated community
Eureka Center, Minnesota, an unincorporated community
Eureka Center, Wisconsin, an unincorporated community
Eureka County, Nevada
Eureka Springs, Arkansas
Eureka Township, Adair County, Iowa
Eureka Township, Michigan
Eureka Township, Dakota County, Minnesota
Eureka Township, Valley County, Nebraska
Eureka Valley (Inyo County), California
Eureka Valley, San Francisco, California, a neighborhood


P.E.
^^^^^
There we go, a retired engineer with LOTS of time. :^)


PS If anyone is interested, I can Email you
the schematic.....

For a nightlight? I think I could work that out myself, but what the
heck. I bet they are some pretty looking drawings!

On Sep 18, 12:18 pm, G. Morgan wrote:

There we go, a retired engineer with LOTS of time. :^)

**** Betchurass.... LOTS of time... That's why I'm on this
newsgroup.....


PS If anyone is interested, I can Email you
the schematic.....

For a nightlight? I think I could work that out myself, but what the
heck. I bet they are some pretty looking drawi

*** Of course you could. However, my philosophy has been
" don't try to re-invent the wheel ".... When I see something
that works good, for less than I can build it for in my home
workshop, I want to learn about it before starting my own
crusade....

I found that there's no way I can do it for a buck, and, whoever
made it, did it well..... No reason to get inventive on this..
Been done... works well... sells cheap... available locally....

Nuf Said ??

Andy in Eureka, Texas


PS So did you want a ***.sche file for PSPICE, or not ??

Andy wrote:

PS So did you want a ***.sche file for PSPICE, or not ??

Thanks, I would have no use for it other than to see your circuit and
notes. If you spent some time on it and it's real pretty I'd love to
have a look. Please include the word "Usenet" in the subject line, as I
have a filter to only let them through. Thanks!

Andy also replies...

Oops, I forgot ..

Eureka, Texas , one of the five Eurekae in Texas

Mine in about 80 miles south of Dallas , in Navarro County,
on the banks of Lake Richland-Chambers..... what there is
left of it during this drought.....

Andy wrote:

Andy also replies...

Oops, I forgot ..

Eureka, Texas , one of the five Eurekae in Texas

Mine in about 80 miles south of Dallas , in Navarro County,
on the banks of Lake Richland-Chambers..... what there is
left of it during this drought.....

I'm in Houston, we are in the same boat as far as h2o goes!

Andy wrote the following:
Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......

They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...

So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....

Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....

Andy in Eureka, P.E.


PS If anyone is interested, I can Email you
the schematic.....


What I am interested in is... What's the company name of the dollar
store where you got them?
Is it "Dollar Store" or some other cheap price store like 'Family Dollar
Store', 'Dollar Tree', 'Dollar General', or some other name?

--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

On Sep 18, 7:17 pm, willshak wrote:


What I am interested in is... What's the company name of the dollar
store where you got them?
Is it "Dollar Store" or some other cheap price store like 'Family Dollar
Store', 'Dollar Tree', 'Dollar General', or some other name?

--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

Andy replies:
In Corsicana, Texas , it is called "Dollar Tree"... We also have
Family Dollar, where things now cost $1.50 USD and Dollar Store,
where things cost $2.00 USD...

Dollar Tree is my favorite. No prices are marked. Everything
there
is a dollar unless it is on sale, and marked down..... I wish they
sold beer..... :(((((

Andy in Eureka, Texas .... P.E.


Eureka, where the telephone lines have more clicks and chirps
than a Ubangi wedding ceremony...

Andy wrote the following:
On Sep 18, 7:17 pm, willshak wrote:

What I am interested in is... What's the company name of the dollar
store where you got them?
Is it "Dollar Store" or some other cheap price store like 'Family Dollar
Store', 'Dollar Tree', 'Dollar General', or some other name?

--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

Andy replies:
In Corsicana, Texas , it is called "Dollar Tree"... We also have
Family Dollar, where things now cost $1.50 USD and Dollar Store,
where things cost $2.00 USD...


Thanks, I have one near me. I'll have to check if they carry them.


Dollar Tree is my favorite. No prices are marked. Everything
there
is a dollar unless it is on sale, and marked down..... I wish they
sold beer..... :(((((

Beer would be less than a dollar if they sold it by the can. :-)


Andy in Eureka, Texas .... P.E.


Eureka, where the telephone lines have more clicks and chirps
than a Ubangi wedding ceremony...


--

Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @

replying to Andy, GranmaBillie wrote:
jungleandy1 wrote:

Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......
They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...
So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....
I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....
Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....
Andy in Eureka, P.E.
PS If anyone is interested, I can Email you
the schematic.....


I really like these nite lights. I'm going to look at the Dollar Store
and see if I can find some more. They are great for all over the house.


--

On 12/11/2014 8:44 PM, GranmaBillie wrote:
replying to Andy, GranmaBillie wrote:
jungleandy1 wrote:

Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......
They are advertised to draw only 0.4 watts ... That would
mean if plugged in 24 hours a day, they would cost me only
35 cents a year ( 10 cents per kwh ) . I kind of like that...
So I took one apart and made a schematic. The
limiting is done by a series capacitor.... I then fed the
network into a PSPICE simulator and checked out the
claim..... Truly, it uses only 0.4 watts of real power.....

Put a big fast-rise power glitch into your simulation to see why
all LED's don't just use series caps for limiting.

A few years ago, the $-store had nightlights with R-G-B leds
that summed to white...sorta...

I went back and bought a sackfull..... If anyone else has
experience with these items, please post your experience....
Sure, the light is weird ( kind of cool, actually ) and it is
only useful if you have been in a dark room for a few minutes,
but that is nomally the case for our household.....
Andy in Eureka, P.E.
PS If anyone is interested, I can Email you
the schematic.....


I really like these nite lights. I'm going to look at the Dollar Store
and see if I can find some more. They are great for all over the house.

On Fri, 12 Dec 2014 04:44:02 +0000, GranmaBillie
wrote:




Andy writes:
I recently bought some blue LED nite lights from our local
Dollar Store ( for $1 USD each ) and find that , while they don't
give out as much light as the 5 or 7 watt nitelights I have been
using, they are perfectly adequate for keeping me from
stumping my toe on the dresser on the way to the
bathroom at 2 am......



I really like these nite lights. I'm going to look at the Dollar Store
and see if I can find some more. They are great for all over the house.

They are good, but, you may want to consider buying a $10 emergency
night light. There are some LED night lights that are also a
rechargeable flashlight. If the power goes out, the bright light goes
on to light the way and is then able to be used as a carry around
flashlight. I have one on each floor and they are very handy when the
power goes out at night.