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Led question - dummy camera

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PanN

New Member
Hi, I'm making a dummy led camera with the goal of it (the led) lasting three+ months (the more the better obviously) and was wondering if anyone could help me with these questions?

What led, resistor, and battery should I use?

And, any rough ideas how long the led would stay lit on a 12v led with a built in resistor and a 4 amp sealed lead acid battery?
 
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Sceadwian

Banned
Buy a blinking LED. One of my sons toys came with a little blinking red LED powered by a couple AA batteries. It wasn't very bright at the end but it was still blinking 6 months later, should last an incredible amount of time powerd from a couple of C or D cell alkalines.
 

fernando_g

New Member
As Sceadwian mentioned, blinking LEDs consume such a low average current, that your lead-acid may self-discharge before the LED's curent exhausts it.

Better to buy some good alkaline AAs (or better still,lithium AAs) and they will last many, many months.
 
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Sceadwian

Banned
C or D cells could last years.
 

Andy1845c

Active Member
I have a thing I saved out of the trash a long time ago. Its basically 5 white LEDs that blink maybe once a second. It was used in a sign that hung from the ceiling in a retail store. It used 4 D cells. It blinked for atleast a month 24/7 before it got tossed due to new seasonal signage. It was still blinking a long time after I saved it. If you use a single red blinking LED, 2 D cells could last you a long time. 3 months easy.
 

colin55

Well-Known Member
Flashing LEDs are fairly dull. Here is a circuit that flashes a super-bright LED and consumes very little overall current.
 
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Sceadwian

Banned
Which is a complete waste of money when you can just buy LED's that blink....
 

Andy1845c

Active Member
yeah, a security camera would normally have a red, diffused indicator type LED, no real need for a bright one. This seems to be a perfect application for a LED with a built in flasher. Then the OP also doesn't have to fit any circuitry into his camera.
 

colin55

Well-Known Member
Flashing lEDs are 50% on and 50% off. The flashing LED circuit is on for only about 5% of the time.
The overall consumption is MUCH less.


That's why I sell it to people who put displays in shops.
 

HiTech

Well-Known Member
I'd opt for the ready made flashing LED as suggested. When you start connecting superbright or multiple leds to a security camera, it can suggest then, that it's a dummy camera. Real CCD cameras use small leds to indicate operation... not to attract attention.
 

Sceadwian

Banned
The blinking led's I've gotten are not 50% duty cycle, it's at least 25% or less, the extra costs of the components and the time to assemble the board is a waste of time for someone that just wants a simple led blinked. And considering that 2 D cells will already last a year or more in said device a little extra efficiency is not a problem. What might be a problem is this being a fake security device, which may be outside or in a real environement where somethign could go wrong with one of the components on the board. blinking LED's are fully encapsulated.
 
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