Controlling the current

Discussion in 'General Electronics Chat' started by sobow6, Apr 9, 2016.

  1. sobow6

    Thread Starter New Member

    Jan 8, 2016
    This may be a dumb question, but I am self teaching myself electronics to be able to make cool gadgets and mods for my motorcycle.

    I am struggling with amperage. How to control it and how to protect my circuits from too much of it. I attempted to reduce the voltage of my battery (12V) to about 6V with a resistor, which worked! However, when I plugged the circuit into my Motorcycle battery it burned the resistor up pretty quickly.. This did not happen on the bench with a series of AA batteries equalling 12V.. I am very confused.

    Thanks! Any help would be appreciated. Please help me understand voltage and current. Thank you!
  2. #12


    Nov 30, 2010
    The best way to protect your devices from excess current is to use devices rated for a 12 volt motorcycle system.
    The battery does not force several hundred amps through each device connected to it. It provides 12 volts. The devices decide how much current will flow because of their internal resistance.
  3. crutschow


    Mar 14, 2008
    What do you need the 6V for?
  4. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    Excellent. It's a rewarding hobby. If you haven't already done so, get yourself familiar with the basics of voltage, current, resistance and Ohm's Law, which links them.
  5. AnalogKid

    Distinguished Member

    Aug 1, 2013
    You don't give any circuit details, so real answers are not possible, but in general...

    The electrical system in a motorcycle is capable of supplying over 100 watts, while a AA battery can supply only a one or two watts. The reason the resistor did not burn up on the bench is that the batteries could not supply enough power to burn it up. The way electricity works, you provide a voltage to a circuit, and the circuit draws the current it needs, up to the point where the power source cannot provide it. This is what saved the resistor on the bench, the batteries acted as a current limiter. The electrical system on a bike also has a limit, but it is much higher.

    sobow6 likes this.
  6. sobow6

    Thread Starter New Member

    Jan 8, 2016
    Thank you! This is helpful! I will keep researching and try again!