[sdiy] Simple clip detect LED circuit

[John Luciani]

On 5/1/06, Seb Francis <seb at burnit.co.uk> wrote:
> It's to detect clipping on the input of a ADC, so LED needs to be
> totally off for below threshold signals, then on for a noticeable amount
> of time if the signal exceeds the threshold for even 1 sample (~20us).

The one-shot that was suggested earlier with a comparator sounds like it
will do exactly what you want.

Does the ADC output a fullscale code for input voltages that exceed its
fullscale threshold? If so you could use the output of the ADC to indicate
when you have clipped. This will decrease your usable fullscale by
1LSB (which may not be exceptable for a low resolution ADC). The
advantage of losing 1LSB of range is no measurement circuitry is
required (only the LED oneshot).

The higher the resolution of the ADC the more difficult the threshold
comparison will be.

(* jcl *)

--
http://www.luciani.org