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Changing AC plug to battery operated

Victoria Nowrangilall

Mar 31, 2018
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Hi,
I hope this is the right forum to post this in - I have a small (disassembled) security camera that needs wall power to operate. My team and I want to use this tiny camera to put in our high-powered rocket to video our rocket's flight. To do this, I need to get the camera to run on batteries. Would this be possible, and if so, what measurements would I have to take to get an equivalent battery?

Also, here are some specs printed on the plug:
INPUT: AC 110-240V
50-60Hz/01A
OUTPUT: DC 5V +/- 0.5V 1000mA +/- 50mA

And I attached a picture of the entire assembly.

Thank you in advance!
 

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KJ6EAD

Aug 13, 2011
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You probably can power the camera with a small battery pack. Measure the voltage where the red and black wires from the power supply board enter the camera board. Expect 5V with the red wire being positive but since I can't assume there are no other conversion or regulation components on the power supply board, it may be less.

How do you intend to capture the video signal?
 

Bluejets

Oct 5, 2014
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In case you are unaware, there are inexpensive miniature camera/transmitter units as used in FPV on quads etc. that may be suitable.
 

WHONOES

May 20, 2017
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In case you are unaware, there are inexpensive miniature camera/transmitter units as used in FPV on quads etc. that may be suitable.
Yes there are. But they have a limited range if you want to transmit directly to a ground base.
 

Bluejets

Oct 5, 2014
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How far would you like to go?
Have seen at least one that works well at 2klm plus.

Now the video is about range testing the actual controller transmitter BUT the camera transmitter operates at the same range.

 

KJ6EAD

Aug 13, 2011
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There's been no indication from the OP that they intend to transmit to ground. It serves little or no purpose to do so.
 

Hopup

Jul 5, 2015
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I'm pretty sure camera in your picture will give you bad quality. You might want to use something better quality for this purpose. Small FPV cameras are usually good for bright environments what you will face by using it on the rocket.

If you want to record video, there are cheap and very small DVR recorders available.
 

BobK

Jan 5, 2010
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You could use a small "power bank" used for charging cell phones. If they are too big, you could make one with a smaller battery, but that is more complicated.

Power Bank

Bob
 

dave9

Mar 5, 2017
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A rocket flight is generally short and light weight can be paramount.

Sever the 5V positive supply to the camera and put it in series with a multimeter to measure current consumption. This will tell you the minimum Li-Ion battery size you need, capable of that current. Finding the tiny battery packs' current ratings is the more difficult part, or determine the max weight it can be an see if a battery of that weight will work, or else the project is a non-starter.

The second issue is minimum voltage. If you're lucky the camera can operate down to the minimum safe discharge voltage of a Li-Ion cell, then you just need a cutoff circuit in series to protect the cell. Either using a variable voltage lab power supply, or getting creative with silicon and schottky diodes in series, you can lower the input voltage to the camera to see how low the voltage can go and based on this, determine if one Li-Ion cell is sufficient or whether you need two in series then a buck circuit to arrive closer to 5V.

After you've determined the minimum battery size that will supply enough current, then there is the required runtime. The rocket will probably reach apogee within a few seconds but if you want to record it parachuting down too, a minute of runtime would be a better goal.
 

Victoria Nowrangilall

Mar 31, 2018
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You probably can power the camera with a small battery pack. Measure the voltage where the red and black wires from the power supply board enter the camera board. Expect 5V with the red wire being positive but since I can't assume there are no other conversion or regulation components on the power supply board, it may be less.

How do you intend to capture the video signal?
I was thinking to disconnect the transformer and connect the camera directly to a battery pack (as you suggested) after making proper measurements. The underside of the PCB that has the camera attached has an SD card slot to which the video saves to, so we won't be seeing it in real time.
 

Victoria Nowrangilall

Mar 31, 2018
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I'm pretty sure camera in your picture will give you bad quality. You might want to use something better quality for this purpose. Small FPV cameras are usually good for bright environments what you will face by using it on the rocket.

If you want to record video, there are cheap and very small DVR recorders available.
The quality isn't too bad actually! I've tested it with the wall plug and looked at the video from the SD card, and it seems to be okay. The problem is that we are very short on time and have a bunch of other things to prepare and test as well...
 

Bluejets

Oct 5, 2014
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There's been no indication from the OP that they intend to transmit to ground. It serves little or no purpose to do so.

To be fair, there is nothing to indicate the Op did not want to transmit to ground.
 

KJ6EAD

Aug 13, 2011
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No; didn't rule out a potato battery either. I make some reasonable assumptions to limit scope. ;)
 
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