120v lamp in 12v socket...

Discussion in 'The Projects Forum' started by jspark, Oct 20, 2014.

  1. jspark

    Thread Starter New Member

    Oct 20, 2014
    I've had conflicting thoughts here and mostly anecdotal theories...

    Can I put a 250w, 120v lamp in a socket assembly rated for 75w, 12v with out a problem? The voltage supplied would still be 120v.

    If I look at amps, I would need 750w at 120v to match the rated current, if I look at resistance I would need 7500w at 120v to match the rated ohms... Does that math apply here?

    I know folks who have done this without incident, but I'm looking for a mathematical justification as to why it would be okay... Or not...

  2. Experimentonomen


    Feb 16, 2011
    NO! ABSOLUTELY NOT!!! What you are doing is not just outright dangerous, but it is also very stupid, if not totally idiotic!!! The 12V 75W socket is NOT i repeat NOT NOT NOT even rated for more than 12V and is thus not insulated for more than that.
    mcgyvr likes this.
  3. jspark

    Thread Starter New Member

    Oct 20, 2014
    I guess I'm trying to understand what the resulting negative is... It's bad, sure... but does the increased voltage create more heat? If so, why doesn't the amperage and resistance increase? Are they not the causers of heat?
  4. alfacliff

    Well-Known Member

    Dec 13, 2013
    teh 12 volt sockets insulation is not designed for 120 volts, and the heat from a 750 watt bulb would probably melt it too.
  5. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    The resulting negative could be a FIRE and possibly a short or potential for electrocution.

    Voltage: The spacing/separation between contacts and type of insulation used in the construction has not been tested to voltages in excess of 12V.
    Could it be ok.. Maybe... it could be ok as manufacturers only test to conditions that the product was intended to or it could be a problem..

    Wattage: The wattage (or roughly the amount of heat given off by the lamp).. could overheat the socket melting it/starting a fire.

    Yes its actually less current flowing through the device so "wire or current conducting elements" aren't the problem but its the amount of "heat" given off by the light that is the issue.

    Safety ratings are their for a reason and 120V lighting sockets are readily available all over the place.
    There is NEVER a time when you should exceed an electrical/electronic devices ratings.
  6. wayneh


    Sep 9, 2010
    I'll add the analogy to drunk driving. Anecdotal evidence of friends getting away with it without incident is NOT sufficient justification for doing it yourself. Stupid is still stupid, even if nature is looking the other way at the moment.