Re: Alternators
John Slade (edalsj(at)igs.net)
Tue, 28 Jul 1998 15:11:04 -0400
I'll take one of those radios which gives out 40 amps. Actually, the
radio possibly uses 40 watts of power, which on a 12 volt system means
it consumes 40/12 = 3.33 amps. I have an old Volvo car radio from the
60's on the bench beside me, solid state rather than tubes, and its
plate states that it uses only 0.75amps at 12 volts. A tube radio would
consume somewhat more since each of those tubes has a heater which would
use about 0.75 amps each. If it has (heaven forbid) a multi-vibrator, it
will use more still. The actual audio output of a normal car radio uses
very little of the measurable input power.
None the less, your alternator (and regulator), if working correctly,
must be able to handle this extra load. I ran a tube radio in my Sunbeam
SIII (Lucas generator) day and night with no problems, along with
additional driving lights, heater blower, windshield wipers etc
depending on circumstances.
John Slade
Manotick, ON