External Power Suppy - Nikon Coolpix 5700

Discussion in 'Digital Photography' started by Donald Gray, Oct 22, 2003.

  1. Donald Gray

    Donald Gray Guest

    I am interested in making a regulated (stabalised) external power
    supply for my 5700 which needs 8.4 volt input.

    Can anyone help with a suitable circuit?

    (Source Voltage probably 9 or 12v)

    Tks
    --
    Donald Gray
    Putting ODCOMBE on the Global Village Map!
    www.odcombe.demon.co.uk
    You do not have to email me, but if you wish to...
    Please remove the SafetyPin from my email address first
    Thanks
     
    Donald Gray, Oct 22, 2003
    #1
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  2. Donald Gray

    Donald Gray Guest

    Forgot to ask...

    Does anyone know the voltage latitude and current needs of the 7500?

    Almost forgot... Please!
    Thank you
    --
    Donald Gray
    Putting ODCOMBE on the Global Village Map!
    www.odcombe.demon.co.uk
    You do not have to email me, but if you wish to...
    Please remove the SafetyPin from my email address first
    Thanks
     
    Donald Gray, Oct 22, 2003
    #2
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  3. Donald,

    I have no experience with the 5700, but currently own both a CP950 and
    CP995. They use different batteries, the 950 uses 4 AA NiMH (which
    are about 6 volts total) and the 995 uses a special Lithium battery
    supposedly rated at 8.4 volts. I find a commonly available 6 volt
    sealed lead acid battery of about 4 Amp Hr. capacity works great for
    both. Local builders supply houses carry these in specialty lighting
    sections, and a simple 6 volt charger works well to recharge them.
    You can get hundreds of shots from a single charge with one of these,
    which I carry in a belt supported leather holder.

    But if you really want to build up a voltage regulator circuit to
    obtain an approximate 8.4 v output from something like a 12 v. source,
    send me an email and I'll reply with a jpg image of such a circuit I
    recently built for another purpose.

    Olin McDaniel, W4PFZ



    To reply by email, please remove "abcd" from Return address
     
    Olin K. McDaniel, Oct 23, 2003
    #3
  4. Correction: the 995 battery is rated at 7.4 volts, not 8.4 volts, but
    the 6 volt described still works fine. It might work on the 5700, but
    I can't guarantee it.

    Olin





    Donald,

    I have no experience with the 5700, but currently own both a CP950 and
    CP995. They use different batteries, the 950 uses 4 AA NiMH (which
    are about 6 volts total) and the 995 uses a special Lithium battery
    supposedly rated at 8.4 volts. I find a commonly available 6 volt
    sealed lead acid battery of about 4 Amp Hr. capacity works great for
    both. Local builders supply houses carry these in specialty lighting
    sections, and a simple 6 volt charger works well to recharge them.
    You can get hundreds of shots from a single charge with one of these,
    which I carry in a belt supported leather holder.

    But if you really want to build up a voltage regulator circuit to
    obtain an approximate 8.4 v output from something like a 12 v. source,
    send me an email and I'll reply with a jpg image of such a circuit I
    recently built for another purpose.

    Olin McDaniel, W4PFZ



    To reply by email, please remove "abcd" from Return address
     
    Olin K. McDaniel, Oct 23, 2003
    #4
  5. Donald Gray

    Donald Gray Guest

    Olin,
    Thanks for the comments and the offer.

    In reality, I was being very lazy and hoping someone had such an
    instant circuit - hence my enquiry. I didn't want to re-invent the
    wheel. (It is 10 years since I did any design work & homebrew!)

    Last night, I decided to reinvent it and have designed a voltage
    regulator - stabiliser based on the LM371 which has an Imax of1.5A

    The output volts (Vout) is dependant on the ratio of two resistors, R1
    & R2, being used to set up the reference voltage. The formula being:-

    Vout=((R2/R1)+1)*1.25

    So, for my needs (8.4v), R2=4k7 & R1=820R which gives 8.41v

    Note: the source (input) voltage should be at least 2.5v higher than
    the Output voltage. That suits a (nominal) 12v source

    The cost of the stabaliser project is about 5 UKpounds, say 6-8 USD

    If anyone is interested, I have done the calculations to give
    stabiliser voltages from 1.9 volts to 27.2 volts utilising standard
    (E24) series resistors, I will email a copy. It is in an Excel
    spreadsheet format. (Don't forget to remove the safetypin from my
    email addy)

    I am assembling the few components and once completed, I will write it
    up and publish the info for anyone interested in having external
    battery power.

    Regards to all



    [snip]--
    73s OM
    Donald G3YPL/exZL1AZC
    Putting ODCOMBE on the Global Village Map!
    www.odcombe.demon.co.uk
    You do not have to email me, but if you wish to...
    Please remove the SafetyPin from my email address first
    Thanks
     
    Donald Gray, Oct 23, 2003
    #5
  6. Unless you really want to build it, I can't imagine that
    it'd end up being cheaper than the Lenmar PRONEL1 $29
    (no car cord) or the Lenmar DVNEL1 $38 (includes car
    cord). I have the equivalent for my Canon camera, and
    it works great. You can charge the battery outside or
    inside the camera, and operate the camery from it.
    I'm pretty sure that there's a little switching regulator
    inside.

    If I were to think of the simplest way to do this it
    would be to use an LM7809 linear regulator and a
    1N4001 diode (0.7 volt drop). This would give you
    1 amp, 8.3 volts, with no need for a resistor divider.
    But I wouldn't do this because by the time I dealt with
    a transformer, bridge rectifier, filter capacitors, line
    cord, fuse, connectors, and enclosure, I'd have spent a
    lot more money for a much larger unit.

    You could also simply buy an adjustable 1 amp regulated
    wall wart, set it to 9V, and use a diode to drop down to
    8.3V, or a 12V regulated wall wart with 5 diodes in series
    to drop it to 8.5V.
     
    Steven Scharf, Oct 24, 2003
    #6
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