Using a power adapter over batteries?

Discussion in 'General Electronics Chat' started by Ravens, Apr 12, 2014.

  1. Ravens

    Thread Starter New Member

    Apr 12, 2014
    6
    0
    Hello

    Hope I'm posting right, haven't used this forum before.
    I recently bought a model which contains a number of LEDs within it, and it came with a battery powered pack, but it was a very poor DIY job by the looks of it. It's obviously not been handled well and is simply not supplying power - I can see one loose wire for one row of the batteries and because a huge glob of glue was used I can't tell if the other attached lead is even making a connection. I've tried various things but just cannot get it to supply power, that or the internal LEDs aren't functioning (which I'm hoping is not the case), but I've got to find out one way or the other.
    So... what I need to know is if I can buy a socket powered adapter instead. The battery pack he created contains four C batteries, at 1.5 volts each (according to the side of the battery), so would I be correct in assuming a 6V power adapter would be the thing to buy? I realise volts may not be the only thing to consider so I'm not just going to jump in and buy something inappropriate or potentially damaging/dangerous. I know nothing about electronics so I'm completely at the mercy of the advice I get here. Clearly I don't want to get anything which will melt or blow up the electronics in the model lol.
    So any advice is greatly appreciated. I've attached a photo of the battery power pack in case it's of any use.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,553
    2,375
    If you get a wall socket power supply (wall-wart) make sure it is the regulated type, the only thing is you may have a problem getting 6v, most are 5,12, 15, 24.
    It may not be that critical, you might get away with a 5v version.
    Max.
     
  3. Ravens

    Thread Starter New Member

    Apr 12, 2014
    6
    0
    It just occurred to me that I perhaps should have mentioned I'm in the UK - since I think wall sockets are slightly different here?
    In any case I've been browsing ebay for power adapters and there are plenty of 6V power adapters to buy, but is that the only consideration to take into account? Some of the listings have different amp ratings as well.
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,553
    2,375
    You could measure the current draw of the existing set up if you have a meter.
    Depending on the electronics involved, it may not be super critical as to voltage.
    Max.
     
  5. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,542
    1,251
    How many LED's? Yes, the line voltage and plugs are different from the US, which means the innards are a bit different, but if it says 220V and fits in your wall socket, it's ok to use. A few LED's is not much of a load, so just about anything you get will handle it. Also, if you keep the output close to 6V it won't matter how much extra energy the AC adapter is capable of. The LED circuits are self-limiting within reason.

    As for the output - If the wall wart is relatively heavy, like it has a standard transformer inside, then the output might not be regulated. That is, a 6VDC unit will make 6V when loaded with its original product (calculator, etc.) but might rise up to 9V with no load or light load like a couple of LED's. A newer one is much lighter for the same wattage capability because it has a switching power supply inside. It also wil have a much better regulated output.

    ak
     
  6. Ravens

    Thread Starter New Member

    Apr 12, 2014
    6
    0
    The internal electronics simply consist of a number of static or flashing LEDs... I'm not sure exactly how many but quite a few for four C batteries to power I'm imagining.
    I can get a meter but because the circuit seems so broken I don't know that it would help me determine anything.
    So you don't believe amps should be a big issue? Most adapters I'm seeing are 500MA but some are 2500MA for example.

    I've attached an image of it lit up to give an example. I can't see inside the model very well as it's permanently closed now accept for a small opening.
     
  7. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,553
    2,375
    I wonder how they get around the outlet fuse requirement, (required fuse in the plug)?
    Otherwise it would be a 30amp fuse behind it at the panel.
    Max.
     
  9. Ravens

    Thread Starter New Member

    Apr 12, 2014
    6
    0
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,553
    2,375
    That could work, providing the current draw does not exceed 600ma.
    Max.
     
  11. Ravens

    Thread Starter New Member

    Apr 12, 2014
    6
    0
    Would that cause damage, or if it were insufficient would it just be a case of simply not working to power the LEDs enough or at all?
    If we were to guess at say there being 100 LED lights, is 600ma likely to be enough? That may be a difficult question to ask I don't know, but I've nothing to scale what 600ma is and how much power LEDs require.

    This perhaps a better alternative? http://www.ebay.co.uk/itm/Universal...ctronics_PowerAdaptors_SM&hash=item35ccaa2479
     
    Last edited: Apr 12, 2014
  12. samuel.whiskers

    Member

    Mar 17, 2014
    95
    2
    More chance of damaging the power adaptor with too high a load, although newer switchmodes do better with cut-outs/overload....

    I'd personally be surprised if that model drew more than 600mA....

    There is no harm in buying the biggest power adaptor you want - I tend to well and truly over-do it, because the price difference between small and large is pretty small, then your more beefy power adaptor may have more use when you've retired the starship.... I'd grab a 6V 2A one and be done with it..... :) Better yet get a selectable voltage version, much more useful another day....

    Lee
     
  13. Ravens

    Thread Starter New Member

    Apr 12, 2014
    6
    0
    So from my newbie perspective and what you've stated Lee, am I correct in saying that just because an adapter is capable of a much higher load, does not mean that it will therefore overload a circuit which does not require that much power? In effect I won't burn out the electronics for having an adapter which is capable of giving much more power than required.
     
  14. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    I doubt that the Enterprise LEDs draw more than 200mA, so either one would work. The one with selectable voltage and interchangeable plugs is more versatile. However, that also makes it more complicated. Just be sure you don't smoke the Enterprise with too high a voltage. And when you are ready to select the plug, use the one with the smallest hole that will go on the socket. And, (yes, there's more) be sure that you have the polarity correct, i.e., plus to plus and ground to ground.
     
  15. samuel.whiskers

    Member

    Mar 17, 2014
    95
    2
    Current - yes - a load (your starship) only draws the current it needs from the power supply. You could hook it up to a 200Ah 6V lead acid battery that is capable of 200A, it will still draw its measly 100mA or whatever..... the battery would just last a long time.... :)

    Voltage - no - you do need to match the voltage, generally, some circuits are more tolerant of variation than others, best to match what the circuit designer suggests.....
     
  16. wayneh

    Expert

    Sep 9, 2010
    12,137
    3,054
    I'd try a standard USB power adapter. They're everywhere (you probably already have one), cheap (you can use it for other things if you don't already have one), and there's no risk of over-voltage to your model.

    If the lights aren't bright enough, then you know you need a bit more voltage.
     
Loading...