logic design question

Hello, I'm trying to build a circuit that has an array of switches (8 switches) and takes in a clock signal and compares the clock signal to my switches one at a time. Then if both the clock signal and the switch are "high" i would like an input signal to be connected to my output. Anything else should result in a break between my input and output signals. I'm having a hard time getting started with this project and was wondering if anyone had any suggestions on how I may accomplish this. My input is a very small audio signal.

thank you.

Reply to
panfilero
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"panfilero" schreef in bericht news: snipped-for-privacy@e3g2000cwe.googlegroups.com...

Hmm... Your description is not very clear, at least not to me. So you have an input signal (one?), small audio, that should be connected to an output (one?) or not depending on some clock. How does this clock arrive? At what time do I compare what part of that clock to what switch? What's next? It may be usefull to tell more about the background too.

petrus bitbyter

Reply to
petrus bitbyter

While contemplating your response to Petrus, you may also contemplate cross posting rather than multiposting :)

Crossposting ensures that a reply goes to all the newsgroups you posted to, so anyone interested sees the reply regardless of where it came from.

Cheers

PeteS

Reply to
PeteS

ok, the signal is from a guitar, the output is to an amplifier. i believe the audio signal from the guitar to be pretty small... millivolts i assume. the clock i'm thinking i will make from a 555 chip, i would like to be able to control the speed of the frequency. i have 8 buttons, when i push a button that button should be "high", my goal is to make something where a clock signal is constantly being compared to these 8 buttons. Whenever my clock signal is a "high" and the button is a "high" i would like the input to be connected to the output, else i would like it to be off. So, if I press all 8 buttons then my output would be an audio signal that is only on when my clock is "high" and it should sound like a stutter. If 1 = connected (sound) and 0 = not connected (no sound) then when all 8 buttons are pressed i should hear 1,1,1,1,1,1,1,1 this should be continuously looping. If the 3rd,4th,6th,7th,8th button are pressed I should hear

0,0,1,1,0,1,1,1 coninuously looping. If i increase my clock speed, then my logic circuit would just loop through these 8 buttons quicker. I'm guessing I'm comparing the clock with each button using an AND function. Audio should only come out if both clock AND button are high.

thank you, i appreciate any suggestions of how to get started with this

Reply to
panfilero

this is actually my first time posting in these things.... how do i cross post? thank you

Reply to
panfilero

Like Newsgroups: sci.electronics.basics,sci.electronics.design

Reply to
Homer J Simpson
[snip]

Is this the kind of thing you want?

This is *not* an engineered circuit, and may not work in practice, but maybe it will give someone ideas...

Set up an 8-bit shift register in a ring configuration, with switches off the outputs as shown. Pre-load the register with a 1, then cycle it with the clock. Each time the 1 hits a closed switch, the transistor base goes high, turning on a relay, pre-amp or audio switch.

.------. | | | .-. | 555 | | | | | --- | | | |---o o------------| | | | T | === | | --- | GND | |----------o o-----' `-------' (created by AACircuit v1.28 beta 10/06/04

formatting link

Reply to
Randy Day

"panfilero" schreef in bericht news: snipped-for-privacy@e3g2000cwe.googlegroups.com...

Well,

Suppose you know how to build that 555 clock. Keep in mind that when you change the frequency, you may change the pulse-pause rate (duty cycle) as well.

Then you need a 3 bits binary counter. The precise type does not matter as long as it counts binary. A 74HCT163 or CD40163 will do. (They're 4 bits counters, you only use the three least significant bits.) The counter just has to count from 000bin up to 111bin and start all over again.

Next you need an eight input multiplexer. 74HCT151 for instance. Connect the counter outputs to the select inputs and the buttons to the multiplexer inputs. Now the multiplexer output will show the button values one by one. An AND-gate and you're done with the logic.

As for the switch consider a CD4066B. You may set all four switches in parallel to reduce the internal switch resistance. An AND-gate can easily drive them all.

petrus bitbyter

Reply to
petrus bitbyter

the

Additionally, you cannot allow the audio signal to go negative, with respect to ground, if the 4066 is running on a single ended power supply such as 5 volts and ground.

Doing so will destroy the 4066. The solution is to run a bipolar power source such as +5 volts, -5 volts and common ground.

Reply to
Lord Garth

Appreciate the suggestions, I think they will definitely help me get started on this thing. Thanks!

Reply to
panfilero

that sounds about right, the part that gets me is how to make it sequence, and check each and gate one by one and then loop and check them again.

thanks.

Reply to
panfilero

A previous poster suggested you use a counter / decoder to sequence your clock through the 8 switches, one at a time.

This is still a correct answer!

Reply to
Lord Garth

Use of AND gates seems to fit your delima! The AND gates for the sampling would simply use the clock and what ever input your sampling. if both are high for example, the AND gate output goes high, that in turn can turn on another INPUT of and gate, where is, the other input of this gate will have your passive signal you want to gate through .

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Reply to
Jamie

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