Solar Panel and powered pump

Discussion in 'The Projects Forum' started by IGraham, Jan 16, 2014.

  1. IGraham

    Thread Starter New Member

    Jan 16, 2014
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    Hello

    Is it OK to directly connect a solar panel to a low powered pond pump ?
    I have a small pond and am in the process of building a small adjacent bog garden/pond and as one is higher than the other water wise I can have a circuit.
    I’m intending to use a solar pond pump to feed a trickle of water from one to the other. But as sunlight isn't that strong up here (NE England) I had thought about buying a low powered pond pump (6v) and attaching a 6v solar panel and to switch of the low power transformer when the sun shone.
    However if the powered transformer and the solar panel are connected direct to the pump ?? will that work will the solar panel be damaged

    If I can do that, could anyone recommend a 6v solar panel that would deliver enough power.
    This is the pump I was thinking of (below) - would be nice if the panel was also ebay cheap
    http://www.ebay.co.uk/itm/WATER-FOU...den_PondsWaterFeatures_UK&hash=item5ae865e27b

    Thanks far any advice you can give
     
  2. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    I think that the pump you linked to can be connected directly to a 6V solar panel. You would not use the mains transformer that comes with the pump. If you choose a solar panel with at least 300mA of current output, it would run the pump at close to full capacity when the sun is bright. Of course, when the weather is cloudy, the pump would run more slowly, and the less light there is, the more slowly the pump would run. When it is very cloudy, or night time, the pump would not run at all.
     
  3. IGraham

    Thread Starter New Member

    Jan 16, 2014
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    Hello tracecom and thanks for replying

    The info as to what solar panel i will need is most useful.
    Do you know if having both a solar panel and a power supply connected at the same time would damage the solar panel - can i put a voltage across the panel.
     
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Depends on the panel. Most have a reverse-blocking diode integrated inside the panel itself. If your specific panel doesn't have one, you will have to add one externally.

    To find out, I would hook the panel (+ to + and - to -) across the output of my lab power-supply. I would watch the supply current meter while slowly turning up the supply voltage. If current flows (backwards) into the panel, then the external diode is needed.
     
  5. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    This panel might be sufficient. http://www.ebay.co.uk/itm/6V-330mA-...21345296572?pt=UK_Gadgets&hash=item33893530bc Notice that the diode that MikeML mentioned is included.

    Two of the panels in parallel would almost certainly do the job.
     
  6. IGraham

    Thread Starter New Member

    Jan 16, 2014
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    hi tracecom & MikeML

    Great thats that sorted, i now know the panels i need and that a reverse current protection diode will allow me to do what i want

    thanks
     
  7. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Add another diode to AC adapter so that AC adapter & solar panel can be " ORd " together. Power source with highest V , or both, will drive the pump.
    If only using solar panel, there will most likley be a problem in starting even when there is enough sun to run the pump.
    A " Solar Gleaner" ckt. can be used to start the pump; " Need help to light up 8 LEDs..." jenovauh, pg 55, post # 546, can be modified for 6 V.
     
    Last edited: Jan 16, 2014
  8. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Not realy necessary. An unregulated wall-wart has a full-wave bridge and filter capacitor. If driven backwards, no current will flow (after the capacitor is charged); it is blocked by the diodes in the bridge.
     
  9. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Point taken, just could not see inside of wall wart, & a small V drop would faver SP.
     
  10. IGraham

    Thread Starter New Member

    Jan 16, 2014
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    Hello

    Need a bit more info
    Have purchased the two solar panels and diodes but am not sure where the diodes should go, is this (attachment) how it should be done and do the white end of the diode go towards the panel or away. One more thing do I solder directly to the panel or would that damage it, is there another way to connect.

    Thanks again for your help, much appreciated
     
  11. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Is the pump to run 24 hrs. per day?
    Is the system to be fully automatic?
    Can you give us the measured V output of the unloaded AC adapter?
    I would connect the two SPs in parallel & bring out two leads long enough to reach the pump. Would anchor leads to SP with epoxy or hot glue to keep strain off of SP tabs. Need answers for remainder of ckt.
    I expect AC adapter unloaded V to be about 8 Vs, same as SP open ckt Vs so that pump might be running on both AC & SP.
     
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