# 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
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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
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Can you sketch out the various configurations you need? Just pencil paper and snap a photo. We don't need fancy.

Apr 15, 2016
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4. ### Tomadws Thread Starter New Member

Apr 15, 2016
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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
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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
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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.

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7. ### Alec_t AAC Fanatic!

Sep 17, 2013
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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
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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.

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9. ### Tomadws Thread Starter New Member

Apr 15, 2016
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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
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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
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An LED on each output of the 74HC151 will tell you which channel you are using.