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Which AA batteries to power 300 LED pixels?

Discussion in 'Electrics UK' started by pretzelz, 19 Oct 2015.

  1. pretzelz

    pretzelz

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    Hi all,

    I would like to power 300 (addressable) LED pixels. This type. They are 5V. I only need to power them for about 30 minutes, maybe 20 minutes.

    Would it be right to buy 8x AA 2100mah battery of a certain type (of which I'm not sure) to power these? The microcontroller I would be buying would be an SD CARD LED controller, the T-1000S

    Many thanks!
     
  2. ericmark

    ericmark

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    0.3W per LED and 50 LED's = 60 mA per LED so 3A a little high for AA batteries but likely two will last for the 1/2 hour if all lamps are on. Just maths. You say 300 not 50 so times 6 so likely 12 batteries will just about do it for half an hour.

    But what voltage is required for the controller? It seems you also need a 7.5 ~ 24 volt supply from what I can see?
     
    Last edited: 20 Oct 2015
  3. flameport

    flameport

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    Totally inadequate, 300 will be 90 watts, or 18 amps at 5 volts, and that doesn't include power for the controller itself.

    No way that 8 AA cells can power those for any length of time, and not clear how you intended to obtain a stable 5V DC supply from AA cells either.
     
  4. ban-all-sheds

    ban-all-sheds

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    It'll be fine - they are dirt-cheap-direct-from-China-carp, so they will

    a) not all work, thus reducing the load, or
    b) stop working quickly, thus reducing the load, or
    c) fail altogether, thus making the battery capacity irrelevant, or
    d) catch fire, thus making the battery capacity irrelevant, or
    e) explode, and blind the OP, thus making it a moot point whether they ever worked, or
    f) all of the above.
     
  5. pretzelz

    pretzelz

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    Thanks for your replies on this topic. I'm sure this project must be possible, even if the lights only get powered for 10 mins.

    The kit has arrived, but at present I'm stuck when trying to get this working with two possible scenarios - though I have a feeling I should only concentrate on getting scenario 1 working. If you could possibly review the two attached scenario pictures, especially scenario 1, and give me your thoughts, that would be great. (see attached pics)

    Scenario 1
    (see attached picture 'scenario1.jpg' )
    The Data and GND from the LEDs are connected to the Data and GND on the T1000S.
    1x 4.8v power pack (Enloop pro) is plugged into the 5V and GND at the top of the T1000S
    1x 4.8v power pack (Enloop pro) is plugged into the red 5V power line of the LEDs.

    I'm not sure where the negative line should be connected from this power pack?

    [​IMG]



    Scenario 2:
    Powered with one battery pack only:
    (see attached picture 'scenario2.jpg')
    The Data and GND from the LEDs are connected to the Data and GND on the T1000S.
    1x 4.8v power pack (Enloop pro) is plugged into the 5V and GND at the top of the T1000S
    The power line of the LEDs are also connected into the T1000S power.

    The result for scenario 2, is that when the controller is turned on (with sd card already inserted) the power light stays on, and the Error light comes on for 1 second only. (I assume the controller is initialising). Then nothing happens. If I press the MODE button on the controller, the Error light flashes once, for about half a second.

    scenario2.jpg


    The controller manual reference can be found here.

    Thanks in advance!
     

    Attached Files:

    Last edited: 31 Oct 2015
  6. ban-all-sheds

    ban-all-sheds

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    Why not as per the wiring diagram in the manual? (The RH side - the left looks a bit dodgy).


    Can't see that in the manual.
     
  7. pretzelz

    pretzelz

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    Good success this evening - spotted I had got the Data and GND lines the wrong way around (after I looked closely at the PCB markings on an LED through the frosted plastic). I've since been able to run 150 LEDs + controller, from one 4xAA battery pack. I grounded the end of the LED chain back to the controller to get an even distribution of power. Worked well. On the weekend will find out if the 4xAA's can handle 300 lights, and for how many minutes...

    I've got an Lloytron 300mA Multi Voltage Mains Power Adaptor AC/DC UK Plug that can do 4.5 and 6v. What would happen if the draw from the LEDs becomes more than 300mA and I use this adapter for testing? Thanks.
     
  8. winston1

    winston1

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    An adaptor that is overloaded will

    1. Shut down if a well designed switch mode type.
    2. Get hot and reduce its output if a transformer type eventually leading to rupture of the thermal fuse if it has one or smoke if it hasn't.
     
  9. pretzelz

    pretzelz

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    Can I check my understanding on something? I've got 300x RGB LED lights, powered by 4x2500 mA batteries. They work well. However for some colours (eg pink), if shown across all LEDs, results in only some pink, and the rest red. I figured not enough mA to power 900LEDs (RGB) required to make this particular colour. So, I'm planning to power the last 150 lights with a separate 4xAA battery pack, but continue to still run the same DATA line from controller all the way through the first 150 lights, and the next 150 lights. Any thoughts on if this could cause problems? Thanks.
     
  10. DIYnot Local

    DIYnot Local

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