channel selector using an IC and momentary switch?

Discussion in 'The Projects Forum' started by Tomadws, Apr 15, 2016.

  1. Tomadws

    Thread Starter New Member

    Apr 15, 2016
    8
    0
    I'm working on a guitar effect stomp box that uses diode clipping. I would like to use multiple arrangements of diodes to achieve different clipping sounds (4 minimum, 8 maximum arrangements.) I would like to use a momentary switch to cycle through all the arrangements in a sequence. Im sure this can be achieved utilizing an IC and/or transistor circuit but I don't know what would work best. Any help is appreciated!
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,061
    3,834
    Can you sketch out the various configurations you need? Just pencil paper and snap a photo. We don't need fancy.
     
  3. Tomadws

    Thread Starter New Member

    Apr 15, 2016
    8
    0
    image.jpeg
     
  4. Tomadws

    Thread Starter New Member

    Apr 15, 2016
    8
    0
    Basically, 1 input that would be a signal in from the effect, and at least four switchable outputs. I suspect I could use a designated voltage and a momentary switch to trigger the circuit to sequencer through outputs? Am I too far off?
     
  5. absf

    Senior Member

    Dec 29, 2010
    1,493
    372
    Yes, you could use half of a 4 to 1 multiplexer like 4052 and a 2 bit binary counter as the A/B address select of the channel. The button is connected to the input of the counter.

    Allen
     
  6. crutschow

    Expert

    Mar 14, 2008
    13,049
    3,244
    A couple observations if you use a counter and a multiplexer:

    Note that multiplexer signal voltage limits typically go between the plus and minus power supplies.
    What power supply voltages do you have?

    The switch to index the counter must have a debounce circuit to avoid multiple counts for each switch press.
     
    absf likes this.
  7. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,804
    1,105
    Wouldn't you also need some way to know which output is currently active, and/or a way to 'reset the counter to zero'?
     
  8. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,061
    3,834
    The 4 inputs of a CD4066 bilateral analog switch could be connected and the chip used as a multiplexer.

    Then you need a second multiplexer (e.g. 74151) to trigger the switches for each switch of the CD4066.

    Then you need a counter to rotate through each channel on the 74151

    And finally, a debounced switch for you to pulse the trigger the counter.

    Issues would be the DC bias because the analog signal has to be between the + and - voltage supply of the CD4066 chip. For simplicity, that a hip allows a +9 to -9 volts if you have a split power supply (or even two 9 V batteries in series with ground being the node between the two batteries.
     
    absf likes this.
  9. Tomadws

    Thread Starter New Member

    Apr 15, 2016
    8
    0
    Awesome, thanks for the ideas. This gives me a good place to start. Dual power supply isn't a problem and I can build the circuit to accommodate voltages needed.
     
  10. Tomadws

    Thread Starter New Member

    Apr 15, 2016
    8
    0
    I had thought about LEDs for channel indication, but decided it was probably more work than it was worth.
     
  11. GopherT

    AAC Fanatic!

    Nov 23, 2012
    6,061
    3,834
    An LED on each output of the 74HC151 will tell you which channel you are using.
     
Loading...