cd4053

[yobleduwop]

Hi, i was planning to use the cd4053 switch that r.g keen made up but not to switch guitar pedals, i intend to use it to switch 12 left and right audio signals to 1 output, i've worked out ill need one switch per channel i want i just haven't figured out how to switch all the controls to low and the channel i want to high all with on hit. I wanted to use simple pushbutton switches and just rig it up in a rack unit, any ideas?
Thanks Joel

[gez]

Multiplexer/demultiplexer might be a better choice.  Couple of 4051s or (I think) a single 4067 would be better.

If you're going to use 12 push button switches, then PIC control would be the 'easiest' option to select a channel, though there ways of doing this with logic.

[yobleduwop]

Im not heaps keen on learning pic just yet, is there any way of doing it logically? I think ill use the cd4051
Thanks Joel

[Processaurus]

i just haven't figured out how to switch all the controls to low and the channel i want to high all with on hit. I wanted to use simple pushbutton switches and just rig it up in a rack unit, any ideas?
Thanks Joel

One way to do it is use a set/reset flip flops for each channel and for each channel's momentary switch run its signal to its channel's flip flop's respective set pin, and with diodes to every other channel's flip flop's reset pin.  You'd need 132 diodes for your project.   Thats just what I'd do with the little bit I know of the 40xx series, no doubt there is a better way to do it.  

[The Tone God]

Can you give alittle more information on your project ? What type of input and output signals are we looking at ? Can the input signals be left hanging when not connected ? What voltage(s) are the signals ? Do you want to switch the channel in sequence or be able to call any channel at any time ?

Right now I think of three 4052s, which are 2x4 switching ICs, which would give you 12 selections. You would need some kind of BCD converter/counter to control the 4052s.

Andrew

[yobleduwop]

I worked in the live sound industry, most mixing consoles these days have 2 stereo channels, and thats simply not enough so instead of wasting two mono channels eveytime we needed a new cd player or computer feed i wanted to make a channel switcher, i only wanted one channel at a time and be able to select any channel, i worked out how to do that i just couldn't find a way to unselect the channel i had previously, so all my input are just rca inputs from cd players or dvd players or vision mixers or computers.
Thanks Guys

[Processaurus]

Could you just do it with a 2p12t rotary switch?

[yobleduwop]

I think if i used the 4051 and a 3p4t switch i could have each pole of the switch being a different control pin, so i would have 4 inputs and one out put per switch and use 6 different chips, switch left right and an led indicator

If i put a 2.2nf electro on each input would i been fine for reducing pops,
Also do i need the Vr input on each channel? as r.g keen had on his pedal switch,
Thanks Guys

[gez]

The 4051 is a multi/demultiplexer.  It has 8 channels and one input/output.  Channel selection is via a 3 bit binary code on three of the chip’s pins.  Although you could use switches to replicate logic1 and logic0 states and send code that way, how do you isolate each switch from all the others?  As mentioned, if you use momentary switches, flip-flops and diodes it can be done, but it's not pretty.

If you're unwilling to learn a little PIC programming (or get someone else to do the programming for you - always an option), and if you're prepared to compromise, you could use an up/down counter with a single momentary switch and rig that up to your 4051/4067 - keep pressing it until you get the channel you require.  This could be wired up to a numerical display so that you can see which selection is made and so you know when to stop pressing the switch.

[RaceDriver205]

Yeah, gezs one pushbutton idea sounds pretty good.
Also, instead of the numerical display, you could have 12 LEDs with the labels on them (CD, TV, DVD whatever), using a demulitplexer chip (74LS154). The only thing is, don't assume this project is going to be a piece of cake.

[gez]

Just had a look at the data sheet for the 74LS154 and it looks as though it's logic only on its inputs, so no analogue routing would be possible (unless I've got the wrong end of the stick).  In common with other chips in that series it would have to be run from a 5V supply too.

The 4067 is an analogue switch that can deal with 16 channels so would be a good choice, though I dare say there'll be some switching noise.

[gez]

Sorry RaceDriver, I see now that you were suggesting the use of that chip for a LED display.

[yobleduwop]

Maybe i should start learning pic or avr, its seems the easier option, Thanks Guys