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Light for a gun safe

C

Chris W

Jan 1, 1970
0
I want to put a light in my gun safe that will come one when I open the
door. Since running power into the safe is more than I want to deal
with, it will have to be battery powered, I was thinking 2 to 4 AA
alkalines. Four LEDs should give me the amount of light I want. I also
want an automatic dimming, where the darker it is in the room the
dimmer the LEDs will be. Since this is going to run on batteries, I
want it to be as efficient as it can be. I went looking at data sheets
and found this,

http://www.catalyst-semiconductor.com/documents/32.pdf

I was thinking of putting a photo cell in parallel with a pot to get the
value for Rset right Does this sound like a good plan or does someone
have a better suggestion? I am just getting into electronics as a hobby
so I'm not too familiar with what all is out there, I mostly just look
through the Mouser and Digikey catalogs.

Also it is my understanding that they are making LED's more efficient
all the time, can some one give me a good source for some of the newest
most efficient LED's? I only need 4 for this project, but I have
another project that will need a lot (around 100) and I don't want to
spend more than I have to. Also, both run on batteries, so the more
lumens per watt the better. Specifically I am looking for 5mm white,
red and green with a viewing angle of 45 to 60 degrees with maybe some
of the whites having a viewing angle of 30 degrees.

--
Chris W

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J

John Smith

Jan 1, 1970
0
Chris W said:
I want to put a light in my gun safe that will come one when I open the
door. Since running power into the safe is more than I want to deal
with, it will have to be battery powered, I was thinking 2 to 4 AA
alkalines. Four LEDs should give me the amount of light I want. I also
want an automatic dimming, where the darker it is in the room the
dimmer the LEDs will be. Since this is going to run on batteries, I
want it to be as efficient as it can be. I went looking at data sheets
and found this,

http://www.catalyst-semiconductor.com/documents/32.pdf

I was thinking of putting a photo cell in parallel with a pot to get the
value for Rset right Does this sound like a good plan or does someone
have a better suggestion? I am just getting into electronics as a hobby
so I'm not too familiar with what all is out there, I mostly just look
through the Mouser and Digikey catalogs.

Also it is my understanding that they are making LED's more efficient
all the time, can some one give me a good source for some of the newest
most efficient LED's? I only need 4 for this project, but I have
another project that will need a lot (around 100) and I don't want to
spend more than I have to. Also, both run on batteries, so the more
lumens per watt the better. Specifically I am looking for 5mm white,
red and green with a viewing angle of 45 to 60 degrees with maybe some
of the whites having a viewing angle of 30 degrees.

--
Chris W

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Try this:
http://www.technologystudent.com/elec1/ldr1.htm


With your chosen device, what were you going to do with SHDN (the PWM
input)?
 
J

John Woodgate

Jan 1, 1970
0
I read in sci.electronics.design that John Smith
Try this:
http://www.technologystudent.com/elec1/ldr1.htm


With your chosen device, what were you going to do with SHDN (the PWM
input)?
He says he wants to use it for dimming, using a photocell and a
resistor. But the impedances are wrong for a CdS cell. He will need to
add at least a transistor (a FET would be indicated, because of the high
impedance of the CdS cell at low light levels) and associated resistors
to do that.
 
J

John Fields

Jan 1, 1970
0
I want to put a light in my gun safe that will come one when I open the
door. Since running power into the safe is more than I want to deal
with, it will have to be battery powered, I was thinking 2 to 4 AA
alkalines.
 
C

Chris W

Jan 1, 1970
0
The gun safe is also a fire safe and I keep many things other than guns
in there.

--
Chris W

Gift Giving Made Easy
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C

Chris W

Jan 1, 1970
0
John said:
I read in sci.electronics.design that John Smith

He says he wants to use it for dimming, using a photocell and a
resistor. But the impedances are wrong for a CdS cell. He will need to
add at least a transistor (a FET would be indicated, because of the
high impedance of the CdS cell at low light levels) and associated
resistors to do that.

How would I hook up the transistor to that chip? Can you recommend any
part numbers with data sheets I can look at?

--
Chris W

Gift Giving Made Easy
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give the gifts they want
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J

John Fields

Jan 1, 1970
0
The gun safe is also a fire safe and I keep many things other than guns
in there.

---
Well, in that case I suggest that you use a 7555 with one section
running as a fixed astable and the second section running like a
one-shot triggered off of the first one. Use an LDR as the second
one's timing resistor in order to vary its output pulse width, and get
your dimming function by driving your LED's in parallel through a
2N4403 driven by the Q output of the one-shot

Use a form "B" reed switch and a magnet to connect power to the
beastie and it only runs (draws _no_ quiescent current) when the door
is open.

Want a schematic?
 
M

mike

Jan 1, 1970
0
Chris said:
I want to put a light in my gun safe that will come one when I open the
door. Since running power into the safe is more than I want to deal
with, it will have to be battery powered, I was thinking 2 to 4 AA
alkalines. Four LEDs should give me the amount of light I want. I also
want an automatic dimming, where the darker it is in the room the
dimmer the LEDs will be. Since this is going to run on batteries, I
want it to be as efficient as it can be. I went looking at data sheets
and found this,

http://www.catalyst-semiconductor.com/documents/32.pdf
I was thinking of putting a photo cell in parallel with a pot to get the
value for Rset right Does this sound like a good plan or does someone
have a better suggestion? I am just getting into electronics as a hobby
so I'm not too familiar with what all is out there, I mostly just look
through the Mouser and Digikey catalogs.
Also it is my understanding that they are making LED's more efficient
all the time, can some one give me a good source for some of the newest
most efficient LED's? I only need 4 for this project, but I have
another project that will need a lot (around 100) and I don't want to
spend more than I have to. Also, both run on batteries, so the more
lumens per watt the better. Specifically I am looking for 5mm white,
red and green with a viewing angle of 45 to 60 degrees with maybe some
of the whites having a viewing angle of 30 degrees.

Sounds like a cool, but over-the-top application.
I used to do a lot of this kind of stuff before I got old.
Now, I'd just put a flashlight inside on the shelf and use
the time I saved not building the light to go shooting ;-)
mike

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C

Chris W

Jan 1, 1970
0
John said:
---
Well, in that case I suggest that you use a 7555 with one section
running as a fixed astable and the second section running like a
one-shot triggered off of the first one. Use an LDR as the second
one's timing resistor in order to vary its output pulse width, and get
your dimming function by driving your LED's in parallel through a
2N4403 driven by the Q output of the one-shot

Use a form "B" reed switch and a magnet to connect power to the
beastie and it only runs (draws _no_ quiescent current) when the door
is open.

Want a schematic?
Sure but I wold also like to know why you are suggesting this over the
chip I found.

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com
 
M

Michael Black

Jan 1, 1970
0
mike said:
Sounds like a cool, but over-the-top application.
I used to do a lot of this kind of stuff before I got old.
Now, I'd just put a flashlight inside on the shelf and use
the time I saved not building the light to go shooting ;-)
mike

I figured I was missing something, that there was some reason why
there had to be a fixed lamp inside, and that it had to come on as
the door opens.

Yes, I'd just put a good flashlight inside, maybe even putting a bit
of rope on it (or chain if you want to get fancy) to attach it to
the inside so it will be harder for the flashlight to go missing.

Michael
 
J

John Fields

Jan 1, 1970
0
John Fields wrote:
Sure but I wold also like to know why you are suggesting this over the
chip I found.

---
Your way might be the way to go, but it seems like too much of a
hassle for me.

Inductor, special caps, Schottky, 1.2MHz, ground plane, PCB layout...

Plus you've gotta order all the stuff, probably from different places,
so in the end you'll have spent so much on it you'd _have_ to keep it
locked up in a safe!
 
J

Jim Yanik

Jan 1, 1970
0
They make small battery-powered fluorescent lamps that use either 4 or 8 AA
alkalines,and are meant for installation in closets where there are no
power outlets.(they also have an external DC power jack for use with a
wallwart)
They're about $10 USD apiece.You can find them at Wal-Mart,Home Depot,or
Lowes.
It would be simple to install a normally open microswitch in parallel with
the existing switch so the open door turns on the lamp.

Alkalines will last 2-3 years in standby.
 
J

Jim Yanik

Jan 1, 1970
0
Chris W said:
How would I hook up the transistor to that chip? Can you recommend
any part numbers with data sheets I can look at?

You could try Linear Technology's LT1932;6 parts and it will run up to 10
white LEDs from a variety of battery voltages.It's a SMD circuit,can be
made very small,about the size of two pennies stacked together.(excluding
the LEDs.) I made one to run 4 LEDS for a 2 AA flashlight.
 
C

Chris W

Jan 1, 1970
0
John said:
---
Your way might be the way to go, but it seems like too much of a
hassle for me.

Inductor, special caps, Schottky, 1.2MHz, ground plane, PCB layout...

Plus you've gotta order all the stuff, probably from different places,
so in the end you'll have spent so much on it you'd _have_ to keep it
locked up in a safe!
I just did some checking and it looks like digikey has the parts I need
and I was going to just use a Digikey PN 33206CA-ND to connect the
SOT-23-6 package to a generic prototype board. I'm guessing from what
you are saying it won't work very well that way, am I missing something?

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com
 
J

John Fields

Jan 1, 1970
0
I just did some checking and it looks like digikey has the parts I need
and I was going to just use a Digikey PN 33206CA-ND to connect the
SOT-23-6 package to a generic prototype board. I'm guessing from what
you are saying it won't work very well that way, am I missing something?
 
D

Daniel Haude

Jan 1, 1970
0
On Mon, 11 Apr 2005 20:48:21 -0500,
in Msg. said:
I just did some checking and it looks like digikey has the parts I need
and I was going to just use a Digikey PN 33206CA-ND to connect the
SOT-23-6 package to a generic prototype board. I'm guessing from what
you are saying it won't work very well that way, am I missing something?

Maybe I'm off-topic because this is an *electronics* newsgroup, but what's
wrong with a normally-closed microswitch mounted such that it is depressed
when the door is closed? You can glue the switch to one of those crazy
magnets out of a harddrive and stick that into the safe behind the door --
a non-invasive and adjustable solution.

--Daniel
 
C

Chris W

Jan 1, 1970
0
Daniel said:
On Mon, 11 Apr 2005 20:48:21 -0500,
in Msg. <%NF6e.288$yO2.27@lakeread07>




Maybe I'm off-topic because this is an *electronics* newsgroup, but what's
wrong with a normally-closed microswitch mounted such that it is depressed
when the door is closed? You can glue the switch to one of those crazy
magnets out of a harddrive and stick that into the safe behind the door --
a non-invasive and adjustable solution.

--Daniel
I guess I wasn't clear. I want the dimming feature because when it is
dark and your eyes are adjusted to the dark you don't need as bright of
a light to see with, and don't want a blinding light when you open the
door. I am still planing on using a door switch of some kind to turn
the thing completely off when the door is shut.

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com
 
J

John Fields

Jan 1, 1970
0
I guess I wasn't clear. I want the dimming feature because when it is
dark and your eyes are adjusted to the dark you don't need as bright of
a light to see with, and don't want a blinding light when you open the
door. I am still planing on using a door switch of some kind to turn
the thing completely off when the door is shut.
 
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