torstai 1. tammikuuta 2015

New Pseudo Random Generator

I have been thinking my Buchla quantized voltages project a lot and decided to move it another direction. I am going to build a Pseudo Random Generator (PRG) that is mostly based on a great IEEE-article "A Versatile Pseudo-Random Noise Generator" by Lipson,Foster and Walsh I will modify their circuits to 24bits and merge it with Bernie Hutchins Capture Wheel idea With it's Feedback-generator logic PRG can generate any shift-register sequence between 1-24. PRG has 24bit Gaussian stepped voltage output that is generated with digital sinc(x) filter (sinx/x). This filter has the rectangular shape in frequency domain which means the output is ideal white noise with Gaussian distribution (see also Hewlett-Packard's Model 3722A Noise Generator documentation I made a simple Excel-sheet that calculated the 24 resistor values needed for sinc(x) weighted summation. You need only 12 different resistor values because the filter is symmetrical between point y=1 (see picture below). You can leave the 6th and 19th resistors out because at y=0 the weighting/gain is 0. Here is also a block diagram of PRG where the blue-boxes will be implemented first. With TTL-logic circuits this implementation is quite complex. The core needs four separate boards. It's all TTL-implementation except the digital-filter board whit the summing OP Amp. With Sync-generator board it is possible to count with this circuit to maximum of 2^24-1=16 777 215 !

Ei kommentteja:

Lähetä kommentti