This projects page contains some assorted projects that do not fit into a specific category. They are the TTL 24 Hour Clock project , Willow Branch Wand, Homemade subwoofer/amp, Facts about Factorable Numbers and a Software Portfolio listing software that I have written.
Other projects that are either longwinded or can be bunched into a specific category appear in a sub index below Projects Page on the left.
These separate pages are as follows:
CAFL Control Algorithm - Research into using Cellular Automata and Fuzzy Logic in control system algorithms.
DOS Bootsector - Did you ever want to know what a boot sector is and how DOS handles booting form a floppy, directories and files? This article investigates what goes on by using DEBUG to take a microscopic view of DOS file systems.
The DFP Project - Overview of audio analysis & processing using software that I wrote in the mid to late 1990's.
Linux Page - A short piece on my experience with Linux and screenshots of running a Windows app on top of WINE in Linux.
Music Page - Sound files generated by the DFP software on the PC.
Recursive Logistic Eqn - The recursive logistic equation provides some unique insight into how chaos can emerge from simple math. kx(1-x) is the innocent looking equation. Who would ever expect chaotic behavior from it. Visit this page for the details.
RF Electronics Projects - This is the projects page specific to RF projects. Such as homemade AM & FM transmitters, VLF rcvr.
Temperature Data Logging -I have also been working on some electronic hardware (micro-controller based) and software for it and a PC for weather data logging.
Wind Chime - In the winter of 2004, I built a windchime with 5 chimes. It uses the pentatonic scale, in which an octave is divided logarithmically into 5 parts. It is built from copper tubing. Page has theory and pictures.
Energy Study - See a basic energy study of the house on the House page of this site.
TTL 24 Hour Clock
This is it, the crazy clock built out of TTL 7400 series chips. It starts with a 10 MHz 7400 inverter oscillator and divides down using 7490 decade dividers set up to divide by 6 or 10 as needed. Some AND/OR logic appears in the design as well to provide a pseudo WWV time code, 1kHz second ticks, minute and hour marker. This output is provided as an amplified audio output. This is dome using a small 1 stage transistor amplifier driving the 2 inch speaker, with series resistor to limit volume. A 1/8in jack is provided as well for driving a larger speaker. The marker is also able to modulate a 1MHz output for a test signal. Three modes of output are provided, 1MHz carrier, 1MHz modulated with steady 1kHz signal and 1MHz modulated with pseudo WWV time signal. This signal and 100kHz,10kHz,1kHz are provided as buffered outputs for off the board use.
The display itself is an array of dual 7 segment common anode 0.75 inch elements, with appropriate 7-segment drivers. Setting is via 3 pushbuttons. Two provide speedups of seconds 1000X and 10X to roll the clock ahead faster than real time, a third button is a halt button for syncing with another clock source. A 10Hz 'heartbeat' LED is provided for debugging purposes. This is connected at the junction between both boards.
One board is the oscillator and divider to 10Hz and the test outputs (1MHz,100kHz, 10kHz and 1kHz. Pseudo WWV 1MHz and audio) and the other board divides down further and has the display and the drivers for the 7-segment LEDS.(3/2007)
Willow Branch Wand
This wand was made from a willow branch that had the bark and small irregularities stripped using a milling cutter in a drill press. Then it was dried out and straightened by clamping it against a 2 x 2 inch piece of wood in the oven at 150 deg F for a few hours. Then it was hand planed, sanded with 80 grit followed by 400 grit sandpaper. The one end was rounded by using the sandpaper. The other end was cut concave using the same milling bit in the drill press. Then it was drilled out to provide the mount for the crystal. It was then carved with an X-Acto knife. Four willow branches were carved into it followed by the 2 rings near the top and bottom. Then it was stained slightly using coffee. When it was wet with the coffee it was clamped against the 2x2 and placed in the oven at 150 deg F to dry. The willow branch carvings were then burnished with a soldering iron with the tip ground sharp to a point. The wand was then masked off around the carved rings and these were painted. The amethyst crystal was then mounted using epoxy while the wand was held upright in a bench vice. This provided an opportunity to give the rings a 2nd and 3rd coat of paint. The next day the masking tape was removed and the wand was given a light sanding with 400 grit paper to remove grain that was lifted after staining. This also sanded off any 'overpaint' from paint seeping past the masking tape. Then it was rubbed with boiled linseed oil lightly. Being that this was a rush project it was once fixtured for straightness and put in the oven for 3 hours at 150 degrees F.
In conclusion willow is a nice soft wood to work with. It carves and sands easy. It also is quite bendable. I selected the straightest piece I could find with a minimum of knots. While it dried with the bark on for several weeks it started to bend. I was able to unbend it through wetting and drying clamped against a 2x2 in the oven at 150 deg F. for a few hours. It has retained its straightness so far.(12/2005)
Homemade subwoofer/amp
Here is a picture of the subwoofer in the truck of my car, pushed back for clarity. Normally it sits right up against where the back seat is and leaves plenty of truck space left. The design constraint on size is being able to get it in the trunk opening. So the size is about 17 inch wide 19 inch tall and 26 inches deep. I designed the cabinet for primary resonance at 130 Hz, the bass reflex slot at 80 Hz and the 12 inch 500W Peak cone is self resonant at 33 Hz. The Q is pretty high. The amp is capable of 250W, which is much more than needed. I tested originally running only 40W into it works well.
Below is the frequency response of the subwoofer as analyzed using the DFP audio analysis and processing software that I wrote.
A white noise WAV file was played out of speaker and the output was recorded using a flat response microphone. The recording was made using the PC so it was rendered in the WAV file format required by the software. It took longer to set the test up than to run it and analyze the results! 4400 samples were taken and the scale was set to show 1/10 the full frequency range. This gives 50 Hz per division.(9/1999)
Facts about Factorable Numbers
There has always been a lot of interest in prime numbers, but it also interesting to consider the reverse. That is just how factorable a number is. Although we normally use a base 10 system, 10 is factorable by 2 and 5 where as 12 is factorable 4 ways, 2,3,4 and 6. In some ways this makes 12 a more interesting number, easy to cut in half, thirds, quarters and sixths. Ten can be cut in half and fifths, fifths which is a sort of odd unit to divide things into. When looking at numbers, 6 is the first number that is actually usefully factorable by 2 and 3. Six is related to sixty which shows up in a number of numbering systems in history. Six is also next to the two prime numbers 5 and 7. Four is one the border of factorability being divisible by 2 and only 2. It is bordered by the two prime numbers 3 and 5. Speaking of primes, many of the lower (like in less than 100) highly factorable (ones that as you count up they have more factors that any number previous) have prime numbers on both sides. As numbers get larger this tendency decreases.
I wrote some software to extract factors by sequencing through numbers, records were made of only numbers that were more factorable than previously recorded numbers. The time and date were also recorded to allow the algorithm to be modified over and over again for more speed. It was somewhat a learning exercise on algorithm efficiency. The factoring problem is a good test case for this sort of thing, because it grows large quickly as for each number, yet more factors have to be tried. Trials increase in an exponential fashion, which is most problematic for computational efficiency. In theory it is incomplete in the sense that to try an infinity/2 number of factors would take more than an infinity of time.
N Number of Seconds Time Date
Factors into Run
6 2 1.669619E-3 16:22:05 02-12-2003
12 4 2.170505E-2 16:22:05 02-12-2003
24 6 4.174048E-2 16:22:05 02-12-2003
36 8 6.177591E-2 16:22:05 02-12-2003
60 10 .1018467 16:22:05 02-12-2003
120 14 .2020236 16:22:05 02-12-2003
180 16 .3022006 16:22:05 02-12-2003
240 18 .4023775 16:22:05 02-12-2003
360 22 .6027332 16:22:05 02-12-2003
720 28 1.203805 16:22:05 02-12-2003
840 30 1.404163 16:22:05 02-12-2003
1260 34 2.216018 16:22:05 02-12-2003
1680 38 3.017204 16:22:05 02-12-2003
2520 46 4.552014 16:22:05 02-12-2003
5040 58 6.783987 16:22:05 02-12-2003
7560 62 10.4784 16:22:06 02-12-2003
10080 70 13.78029 16:22:07 02-12-2003
15120 78 21.21262 16:22:10 02-12-2003
20160 82 29.24718 16:22:13 02-12-2003
25200 88 38.20403 16:22:53 02-12-2003
27720 94 43.19873 16:22:56 02-12-2003
45360 98 82.41648 16:23:19 02-12-2003
50400 106 95.52721 16:23:27 02-12-2003
55440 118 109.2424 16:23:36 02-12-2003
83160 126 197.8854 16:24:38 02-12-2003
110880 142 308.0244 16:26:03 02-12-2003
166320 158 592.467 16:29:57 02-12-2003
221760 166 958.5184 16:35:14 02-12-2003
277200 178 1407.269 16:41:54 02-12-2003
332640 190 1933.817 16:49:52 02-12-2003
498960 198 3983.403 17:21:38 02-12-2003
554400 214 4817.995 17:34:46 02-12-2003
665280 222 6713.105 18:04:47 02-12-2003
720720 238 7798.542 18:21:41 02-12-2003
1081080 254 16761.02 20:41:04 02-12-2003
1441440 286 28744.83 23:50:57 02-12-2003
2162160 318 146865.6 16:28:58 02-13-2003
2882880 334 277157.9 04:37:14 02-14-2003
3603600 358 418635.1 03:20:20 02-15-2003
4324320 382 484836.3 21:35:25 02-15-2003
6486480 398 1096242 19:34:38 02-19-2003
7207200 430 1470300 03:21:51 02-22-2003
8648640 446 1974546 07:20:26 02-25-2003
The chart below shows a bit more detail, such as the delta which represents how many more factors does the current number have than the previous most factorable number. It increases as would be expected, but not monotonically. It also shows the factorial associated with the appropriate numbers and the near primes for most of the cases. Many of the highly factorable numbers are also factorials (!). As in 6 = 1*2*3. Looking at the spacing on the chart below it can be seen that the factorials spread out sort of logarithmically as the numbers get larger.
For a chart produced by the program FactorC & FactorCa that shows all of the factors for numbers 1-60, marking off primes with the letter P. The second file only shows numbers where the number of factors is larger than the previous value.
Factors #1-60Factors Larger and Larger # < 100,000
N Facs Delta ! Near Primes
6 2 3 5 7
12 4 2 11 13
24 6 2 4 23
36 8 2 37
60 10 2 59 61
120 14 4 5
180 16 2 179 181
240 18 2 239 241
360 22 4 359
720 28 6 6 719
840 30 2 839
1260 34 4 1259
1680 38 4
2520 46 8 2521
5040 58 12 7 5039
7560 62 4 7559 7561
10080 70 8 10079
15120 78 8 15121
20160 82 4 20161
25200 88 6
27720 94 6
45360 98 4 45361
50400 106 8
55440 118 12 55439 55441
83160 126 8
110880 142 16 110879 110881
166320 158 16
221760 166 8
277200 178 12
332640 190 12
498960 198 8
554400 214 16
665280 222 8
720720 238 16
1081080 254 16
1441440 286 32
2162160 318 32
2882880 334 16
3603600 358 24
4324320 382 24
6486480 398 16
7207200 430 32
8648640 446 16
Software Portfolio
I am keeping a list of software that I have written for reference and for anyone that is interesting in more detail.
Software Portfolio
Original Build Date:12-23-2005
Last updated 10-31-2007