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Pseudo randomness based on this

bigkim100

Apr 17, 2013
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Thanks to Bertus, he has sent me to this schematic.(see attachment, simple random sound)
Taking into consideration my fevered analogue driven mind is there any way to make it a PSEUDO
randomness (when I say random I get jumped on that this way is not TRULY Random)
to it without a bucket of ics, LEDs and transistors as seen in my attachment* (altho someday I want to make that circuit to do nothing but hang on my wall, and look impressive).

As I ask this, I tripped over the circuit appearing this tho.
http://www.yusynth.net/Modular/EN/RANDOMGATE/index.html
is there any other suitably analogue way??...or have I reached my limit of simple pseudo randomness that will fit in my brain?

As per usual, thanks

*-I cannot seem to download it at this moment, stand by for action!!
 

Attachments

  • simple-sound-effect-generator-circuit-using-ic-555-and-ic-4017 (1).jpg
    simple-sound-effect-generator-circuit-using-ic-555-and-ic-4017 (1).jpg
    77.7 KB · Views: 14

bertus

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Hello,

Here is a little circuit from my own design.
It contains 4 oscillators made from a inverter chip and a R-2R network for voltage creation.
It will create a random voltage of 16 levels:
Random voltage generator.png
As you can see the oscillators have all different frequencies.

Bertus
 

bigkim100

Apr 17, 2013
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Holy Crap Bertus!!...Im breadboarding this tomorrow. I can only guess that this is infinitely expandable!!!(within reason)
 

bertus

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Hello,

In the schematic you see 2R and R.
This means that the resistors 2R have twice the value of R.
For example : 20K for 2R and 10K forR.

Bertus
 

bigkim100

Apr 17, 2013
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So the op amp constantly runs it and changes the voltage?
what is the standard Vin for this (other than the operating voltage of the op amp)?
 

bertus

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Hello,

The chip can be an 40106 cmos inverter or 74(ls)14 ttl inverter.
There are 6 inverters in each chip.
The CD40106 will work from 5 to 15 Volts.
The 7414 will work on 5 Volts.
See the attached datasheets for more info.

Bertus
 

Attachments

  • 74HC_HCT14.pdf
    238.6 KB · Views: 2
  • cd40106bc.pdf
    68.8 KB · Views: 2

bigkim100

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while I have everyone's attention, can this TL071 be added to the out put of any basic Function Generator(2206, lm324, 8038), to vary the overall output??Tl071 output.jpg
 

bertus

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Hello,

The 4 oscillators are so called relaxation oscillators:
74HC_HCT14_relaxation_oscillator.png
Bertus
 

bigkim100

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2 questions
-Is 2r and r the same across all the different op amps of the ics?, with the oscillation frequency controlled byt the various caps and resistors on the inputs?
-Are these NPO capacitors or electrolytic??
 

bigkim100

Apr 17, 2013
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Ok, Im having a hard time driving it with my 55/4017 circuit, can you help, I feel rather stupid regarding this.
Thank you
 

bertus

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Hello,

The circuit is ment to be used with 40106 or 7414 oscillators.
The 40106 can be CD40106 or HEF40106.
The 7414 can be SN74LS14, SN74HC14 or SN74HCT14.

Bertus
 

bigkim100

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Its actually the interfacing of the 4017, and the cd4010that is boggling me
 

bertus

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Hello,

Do you mean the schematic in the first post?
The labels on the 4017 are all wrong.
Sorry that I did not notice the labeling.
These are the correct labelings:
4017_connections.png

Bertus
 

bigkim100

Apr 17, 2013
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Hello,

Do you mean the schematic in the first post?
The labels on the 4017 are all wrong.
Sorry that I did not notice the labeling.
These are the correct labelings:
View attachment 55662

Bertus
Thank you bertus, Im just not getting you regarding the 4017 working with your R-2R DAC circuit
 
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