Comparing resistors to fuses is like comparing apples to oranges.
Fuses are very low in resistance and contribute very little to the overall
resistance to the circuit. Putting 3 fuses in series or parallel makes basically
no difference in the amount of current flow (ohms law), however it will make a
big difference in the MAX amount of current the circuit will draw before the
fuses blow. Experiment take a high beam headlight (about 55-60 watts) 60 watts
/ 12 volts equals 5 amps (ohms law again) hook the headlight up to a battery
with three 2 amp fuses in series (will blow) circuit drawing 5 amps. Ohms
law--- in a series circuit the current travels at the same rate through all
components. In a parallel circuit the current is split equally if the
resistance of each component has the same resistance.
A very simple analogy would be... A chain is composed of a series of
links.........( where have I heard that one before)
Or, What will handle more current, 3 -16 gauge wires 1 foot long in parallel or
one -16 gauge wire 3 foot long.
Okay, I'm out of breath now.
Scott Hilmoe
Electronics technician for 15 years
John McCarthy wrote:
> Lots of people correcting this one, but Terry is right on the outcome of
> resisters in series...simple OHM's law E=I X R..Resistors in a series is RT=
> R1+R2+R3+... Resistors in parallel get ugly where voltage will take the
> path of least resistance..Resistors in Parallel RT= R1 X R2 divided by R1 +
> R2. As suggested for using the same value resistors in parallel RT = R
> divided by N (#of resistors). I will not begin to tell anyone how to fix
> their roadster..I havent turned a wrench on mine yet..still stuck in
> Bosnia...Buddy
>
> >From: "Terry and Donna Cost" <tcost@vvm.com>
> >Reply-To: "Terry and Donna Cost" <tcost@vvm.com>
> >To: "Datsun Roadsters" <datsun-roadsters@autox.team.net>
> >Subject: 66 amp alternator
> >Date: Mon, 21 May 2001 11:59:52 -0500
> >
> >In a one wire setup you are only charging the battery, and the battery
> >supplies energy to the rest of the system. The alternator only pulls max
> >amps when the battery is completely drained, like pulling the coil wire and
> >grinding the starter until you run out of juice, or turning on a 150 watt
> >driving light without starting the engine, and leaving it on for a while.
> >Put a 30 amp fuse into the wire from the alternator to the battery to
> >protect the rest of the system if the alternator malfunctions and tries to
> >overcharge the battery, or if there is a short in the system, which was
> >designed for less than 30 amp loads. If you really want to protect the
> >system, put three 30 amp fuses in series, for a grand total of 90 amps of
> >protection. A diagram is below.
> >
> >Alternator
> > |
> > |
> >30 amp fuse
> > |
> > |
> >30 amp fuse
> > |
> > |
> >30 amp fuse
> > |
> > |
> >Battery
> >
> >
> >If you put six 15 amp fuses in series, you get the same protection. Or
> >nine
> >10 amp fuses.
> >
> >Leisure Suit Terry
>
> _________________________________________________________________
|