MOTM

There's no "right answer" to how gate and trigger delays should work; 
everybody has their own opinion. What follows is my opinion on this 
topic.

At 3:56 PM +0000 2003/05/15, paulhaneberg wrote:
>The first question is what happens if the incoming gate ends before
>the delayed gate has been produced (assume a delay of 3 seconds with
>a gate length of 1 second)  is the delayed gate still produced at
>the output?

Yes.

>or must the incoming gate be present to enable the
>delayed gate to be produced at the output?

No.

>This leads to the second question.  If the delayed gate is to be
>produced at the output even if the incoming gate stops, what happens
>if the key (or other event) is pushed a second time before the
>delayed gate is output?

You get a second gate.

>Should the relationship between the leading
>edgeof the first gate, the trailing edge of the first gate and the
>leading edge of the second gate be preserved?

Yes.

>This is important because it seems to me if multiple events are to
>be all delayed and fed through to the delayed output, the circuit
>must be a sort of 1-bit shift register with the delay control either
>selecting a tap or controlling the clock speed.  If multiple events
>are not to be preserved a simple analog circuit involving a
>capacitor for timing and a couple of analog switches will do the job.

Multiple events need to be preserved.

Here's a sneak preview of my logic delay line that also works as a 
gate/trigger delay:

http://www.tellun.com/motm/diy/tln774/TLN-774.html

This panel mockup is already a little out of date, but the thing does 
preserve both edges of a signal and stores multiple events. In my 
opinion, that's the only way to go.