[sdiy] pushbuttons? -> sequencer

[WeAreAs1 at aol.com]

In a message dated 12/15/03 2:17:32 AM, zifcak at hotmail.com writes:

<< i am trying to make a percussion sequencer from a 4017, and i am wondering 

the best way to convert the pulse train to usable triggers. the summed outs 

by themselves don't go down to ground long enough to trigger well on the 

next step. any suggestions?

 >>

You need to integrate the 4017 outputs.  That is, run each them through a 
little R/C network.  You'll also need to run the out of that through a diode, too 
(to block any negative-going signal in the integrated output).  Here's a 
rough idea of what I'm talking about (display with a mono-spaced font):

                   C       1N914 diode
4017 output >------||---+----|>|---------> to your summing node
                        |
                        |
                       <
                        > R
                       <
                        >
                        |
                        |
                      -----
                       ---
                        -

I don't know what values to resistor and cap should be.  Maybe someone else 
will have some suggestion for that.  The cap will probably be somewhere in the 
0.1uF to 0.01uF range (don't use electrolytics or tantalum caps - use a 
non-polarized type, mylar or ceramic will work fine).  You will need to duplicate 
the circuit for each of the 4017's outputs (8 or 10 times, depending on how many 
of the outs you're using).  This will give your sequencer nice short little 
output pulses.

Michael Bacich