On 13/06/2011 13:06, Bob Ammerman wrote:
>>> I am assuming that the tuner runs the LEDs continuously at the tuning
>>> frequency while it is in use. If that is the case then there is no sens=
e
>>> in
>>> using a really large cap. You only need one to hold enough charge for o=
ne
>>> pulse of the LED. You certainly aren't likely to have one big enough to
>>> hold
>>> a charge through a whole tuning cycle, which I am guessing will be at
>>> least
>>> several seconds.
>>>
>>> -- Bob Ammerman
>>> RAm Systems
>>>
>> It is to be noted that with a tuner, even one pulse at 1:10 duty can be
>> in the order of milliseconds at the lowest frequency.
>> With mine the lowest frequency is around 16Hz (about the lowest audible)
>> so 1/16 =3D 62.5ms @1:10 duty =3D 6.25ms pulse length.
>> This is assuming you keep the pulse length a ratio of the frequency and
>> not some standard length which is independent.
> It's a guitar tuner. How low can you go on a guitar?!?
>
> -- Bob Ammerman
> RAm Systems
>

The lowest note in standard tuning is E2, which is 82.41 Hz. However=20
most tuners (including this one) tune bass guitar as well, since the two=20
are commonly used together and share the same tuning (bass tuning is the=20
same as the bottom 4 strings of guitar one octave down)
So, the lowest note mine currently goes to is the bottom string in a=20
"dropped" bass tuning, which is D#1 at 38.9 Hz.
However since there are plenty of weird and wonderful stringed=20
instruments and tunings for them, I was going to add a custom setting=20
for non-standard tunings, based on a look up table of all the notes from=20
C0 (16.35 Hz) up to C10 (16744Hz)
So even with the "normal" setting, the (low string) pulses would still=20
be in the order of milliseconds. For a low guitar E it's ~1.2ms at 1:10=20
duty.




--=20
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