Author Topic: LED camp light converted to usb power  (Read 2834 times)

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dnix71

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LED camp light converted to usb power
« on: January 18, 2013, 11:26:06 PM »
I made a couple of these without the internal diode to drop voltage. My boss at work was given one and left it plugged in all day every day until it burned out. USB port voltage is too much. The cheap high amp diodes at Radio Shack also drop almost a volt, which reduces the voltage to what it would be if it were run on batteries, as intended.

The local auto parts stores sell these lights for about $10. The usb cable came from discarded ups backup data cables (proprietary usb to ethernet). The diode is a 6 amp 50 peak inverse voltage diode from RS.

The pictures below show it plugged into my mac laptop usb port. The room light was off for the first two pics.


With my finger over the flash




Crispy

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Re: LED camp light converted to usb power
« Reply #1 on: January 19, 2013, 07:01:53 AM »
Would one of the newer cell phone chargers with the USB connection work for this? That way you could use the light without the computer on.
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dnix71

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Re: LED camp light converted to usb power
« Reply #2 on: January 19, 2013, 11:19:17 AM »
A usb charger should work just fine. USB 1 and 2 are famous for being underpowered on a computer, the chargers have to have more power than a computer port.

Simen

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Re: LED camp light converted to usb power
« Reply #3 on: January 19, 2013, 04:38:42 PM »
The standard max amp for a pc usb-port are 500mA... :)
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Bruce S

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Re: LED camp light converted to usb power
« Reply #4 on: January 24, 2013, 09:22:41 AM »
For me; the interesting part is when you take a picture and it shows the light levels.
The light our eyes can adjust to and what the camera sees aren't the same.
This is probably due to the nature of LEDs being a directed light.
The light you're showing I'm sure is more than enough to walk around and more than enough to to see by.
Pretty cool use of those tent lights ya got there! ;D!
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dnix71

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Re: LED camp light converted to usb power
« Reply #5 on: January 24, 2013, 10:16:10 AM »
Bruce I do have some trouble showing the real light level. I'm not camera savvy enough to set manual exposures, so I left it on auto and covered the flash. The light won't light my 14 x 15 foot room very well but it's more than enough to see my way around at night if the power failed. The 2 watt draw won't drain my battery bank either. The 1.8 watt 18 LED clusters sold on eBay will light a room, though, because they are configured to disperse the light around better.

The flash on my camera is quite bright. I took a night shot of my front door with the led bar over it and it look like daylight because of the flash. That camera eats batteries but it will take a clear picture if you just set it to auto and let it do the thinking for you.

Bruce S

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Re: LED camp light converted to usb power
« Reply #6 on: January 24, 2013, 05:58:50 PM »
GHURD was the one that got me into turning the current down to 1/2 of max just so I could see how well a person could see with so little light. :D.
The problem with camera light is they can't determine light levels from LEDs properly due to their focused  nature.
Have fun too!
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