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electronic wizards in the house???????

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  • 28-10-2003 5:48pm
    #1
    x in the city
    Closed Accounts Posts: 7,134 ✭✭✭


    i am doing a electronic project for my diploma, and one part requires a solar panel to keep a ni cad battery constantly charged, (ie when it runs low the solar panel will kick in and give it some boost)

    i could maybe use a comparator or a shunt controller but am unsure of how to go about it.

    any ideas wizards???????


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    #2
    gobby
    Registered Users Posts: 1,253 ✭✭✭gobby


    does the system have an external power supply or does it have to use the power from the battery/solar panel?

    you might need to use some zeners as a reference and then a comparator.

    it might get complicated if you need to draw power from the battery while charging it.

    do some research into how this concept is worked in cars. im sure there would be lots of info on the web bout that.


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    #3
    ZENER
    Registered Users Posts: 6,163 ✭✭✭ZENER


    Does the charger have to charge up the battery quickly ?
    What current/voltage can your solar cell deliver ?
    What is the load current that must be supplied by the circuit ?

    There are a few circuit designs that could do this job the only problem is they would draw off some of the available power from the sources. A simple "dirty" charger circuit may suffice.

    Can you give us some more information about the purpose of the circuit ??

    Tinky


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    #4
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 91,578 Mod ✭✭✭✭Capt'n Midnight


    Trivial solution - one resistor and a diode.
    Some NiCAD's can trickle charge at less than C/10
    - so just leave it on all the time...
    You can also get NiCADs that can take a fast charge.

    In winter in Ireland solar panels can't kick in most of the time simply beacuse it's dark, and even when there is light it's cloudy - so trickle charge..

    For a 4Ah battery 400ms is C/10..


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    #5
    ZENER
    Registered Users Posts: 6,163 ✭✭✭ZENER


    I dont think the NiCAD is a 4Ah somehow . . . but we await further information !!

    Tinky


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    #6
    x in the city
    Closed Accounts Posts: 7,134 ✭✭✭x in the city


    folks

    its a 7.5 v solar panel, i got 2 of them, 40mA each

    the rest of the project is a altem microcontroller a dallas RTC and a LCD display panel

    i will be displaying the time/date/day on the LCD via the real time clock. the unit runs of the ni cad which is constantly boosted at low voltage by the solar circuit.
    i actually found a useful schematic on this and it looks the business....

    opionions?

    im not too worried about lack of sun, if this project pulls of ,i will be dancing naked. im told its a very good project to work on.

    i saw these monster solar panels down in australia driving a lighthouse station and that was what got me hooked on these....:p


    http://www.solorb.com/elect/solarcirc/scc2/index.html


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