[sdiy] Tap Tempo

[Magnus Danielson]

From: Scott Gravenhorst <music.maker at gte.net>
Subject: Re: [sdiy] Tap Tempo
Date: Sat, 31 Dec 2005 08:11:37 -0700
Message-ID: <200512311611.jBVGBbp07563 at linux7>

> "D A F" <polaris30 at ncx.com> wrote:
> >This might be a dumb idea but could it be done with a phase-locked loop =
> >of some kind?  I dont recall them being used to track frequencies in the =
> >single digit hertz range but could it be done?
> >
> >Dave
> 
> PLLs will respond that low easily, but they have no "memory".  Once the
> tapping reference input ceases, the PLL's VCO will return to it's natural
> free running frequency.
> 
> Memory is why this application is best left to digital, esp. microprocessor
> circuits.  I would think that this is an easy job for a PIC.

... to implement a PLL of sorts in digital yes.

PLL says nothing about form of implementation. For long term memory
(> 1-10 sec) some form of digital memory is recommended.

Cheers,
Magnus - implements PLLs in analogue and digital as I see fit