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Mains to DC power supply for an Olivetti Philos 33 laptop - slightly higher voltage oK ?

Discussion in 'Laptops' started by Roger Walker, Dec 9, 2003.

  1. Roger Walker

    Roger Walker Guest

    Hi. Don't suppose anyone has a power supply for an Olivetti Philos 33
    laptop they could sell me. (for 240v ac mains). Or one for something
    else that delivers 18V, 2.4A? The DC power in socket is a simple
    barrel type, not one of those multi-pin ones.

    There seem to be a lot of 19V adaptors around for different laptops.
    I'm tempted to believe that the slightly higher voltage could be
    handled by the power regulation components inside the laptop. Any
    experience with this? My portable minidisc player was rated at 6V but
    ran off anything between 4.5 and 12!

    Would but a multi-voltage universal supply, but they seem a bit
    expensive considering the low value of the laptop.

    Thanks
    Rog
    (Please reply to newsgroup only)
     
    Roger Walker, Dec 9, 2003
    #1
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  2. On the other hand there are a lot of 16V supplies too and those
    would be a far better choice. The laptop is most certainly
    deisgned to run off car battery power which can be 16-18V.

    Laptop power supplies are regulated so 19V should not be a problem
    (see below). But this is at your own risk of course. The 19V
    supply could be on the upper limit of its tolerance and the
    nominal 18V laptop regulator on its minimum. The total difference
    could be "pushing it". Unlikely and unless the laptop was very
    dear I would have no qualms but then I would also measure the
    actual voltage to be sure it did not go over 19V.
    Because it is a, no doubt, simple battery operated design, along
    with normal good conservative engineering, as yours seems to be,
    4.5V will be well within its lower operating limit. It may go as
    low as 3V but that is not recommended due to the electromechancal
    components..

    The 12V is thus sheer good design and your very good fortune. It
    is _not_ in your best interests even for short term use.
    The unit was probably designed to withstand close to12V
    temporarily when first connected or switched on. This is to allow
    for wal-wart/line power line voltage tolerances and the poor
    voltage regulation of typical wal-warts. Some 6V rated ones can
    reach 10-12V when not loaded.

    It will drastically shorten component life. Close to 7V.is a safe
    upper limit.
     
    H. Dziardziel, Dec 10, 2003
    #2
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