Archive for May, 2019

Folsom Sage

26 May 2019

My “photo of the week” is of a lovely sage plant which I pass when I go to Folsom to shop.

sage-flowers-20190525-63

By my best guess, this is a sage “cultivar” called Allen Chickering. Genetically it is a hybrid, and per my understanding of the term cultivar, the plant has been enhanced for visual appearance and aroma by selective breeding.

Currently this plant is mid its rather short flowering season, but this has perhaps been prolonged by an unusually rainy Spring. Sage is one of the favored native plants for this area, due to its drought resistance and pollinator-friendly flowers.

As mentioned earlier, my trips to Winco in Folsom save me money on food, and continue to be entertaining and a good way to get in some moderate exercise on the weekend. These days I almost always bring my camera along, as there’s no telling what will turn up along the way.

Mather/Mills in Rancho Cordova

On this trip I had to stop somewhere to wait for the train that goes all the way to Folsom, and I chose the Mather Field/Mills station. This route mostly follows Folsom Blvd, and it passes many historic locations, as this road is one of the oldest in the area.

For much of the route, the light rail parallels a conventional train track. It is hardly ever used now, but harkens back to times were trains were the major passenger and freight service. One structure from that period that has been saved and reused is the station house/tavern/dance hall that was built in 1911.

mills-station-building-rancho_cordova-20190525

Next door is a small park with a kiosk containing historic information and a decidedly non-historic little sculpture that looks like it would be fun for kids.

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Harmonics

24 May 2019

One of my interests is creating projects that demonstrate physics concepts. This is particularly true for physics concepts that are mentioned by Mr. Hubbard in has writings or lectures. One such concept is harmonics.

harmonics-with-frequency-values

The above representation, obtained from an educational website, illustrates the basic idea here. “Hz” stands for Hertz, the chosen name for a unit of measure of frequency, previously known as Cycles Per Second.

These terms, as far as I know, are borrowed from the world of music, where they have been in use at least since the time of the Greeks, who liked to play around with the mathematics of vibrating strings.

One way of looking at harmonics is the idea that they can be derived by taking a string and dividing it into different numbers of parts that add up to the total length. That gives you a series of whole fractions for different string lengths (periods), and a series of whole number multiples for frequency (or tone). In audio, we usually refer to frequencies rather than wavelengths or periods.  In radio and light, you are more likely to see wavelengths referred to.

The harmonic series illustrated above contains two octaves. An octave is a frequency exactly two times another frequency. In music, octaves are given the same note letter, as they indeed sound like the “same” note.

Traditional musical scales

Traditional music scales are based on whole fractions. It was possible to determine relationships between notes using fractions before we had electronic means to measure frequency. Thus, a traditional musical scale would be made up of a fundamental tone and then a series of chosen higher tones relating to the fundamental by whole fractions of a value between one and two. The most common notes used were sub-octaves of the harmonics of the fundamental tone. Thus: 3/2, 5/4 and 7/4, 9/8, 11/8, 13/8 and 15/8. Many other tones are possible, but it was found – or considered – that these sounded the most musical when played together. Modern tuning systems approximate these notes while creating a scale that makes transposition between keys (scales starting with different fundamentals) much easier.

My project

With my project, I just wanted to demonstrate what several harmonics of a fundamental sound like.

The biggest challenge in generating such tones electronically is to get a pure tone (sine wave). Sine is the name of the function that describes a pure tone. It is a term taken from trigonometry (the study of the properties of angles and circles).

I wanted six sine waves that were exact mathematical multiples of the fundamental. The only practical way to achieve this is starting with digital signals. Those signals can then be built into sine waves using various processes. I was a little nervous about how well this would work, and how easy or difficult it would be to create good sine waves. But it worked out OK. In this design, most of the sine waves are constructed from 16 voltage steps. For the fundamental tone, I made knobs to control the size of the voltage steps. For all the other tones, I used fixed resistors. The basic idea was taken from a magazine article from the 1980s that I had saved in my digital library.

This project works fairly well. The power supply was a little complicated, because I needed four different voltage rails: +10V, +5V, (ground = 0V), -5V and -10V. My fixed-resistor sine wave generators work quite well. The one using variable resistors is a little flaky, but does an acceptable job. I get seven harmonics from this equipment, including the fundamental, and I can mix them in different ratios to get richer sounds.

I built this into a cabinet that was already occupied by an old multimeter I purchased years ago. I decided there would be enough space for it without removing that old meter, so it remains a part of the project. I can even use it to measure the amplitude of the output signal!

harmonics-project-7

 

A Hodgepodge

19 May 2019

Creepy Caterpillar

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Two weeks ago in Folsom I came upon this little creature at the Light Rail station. Turns out it is a Tussock Moth caterpillar. This family of moths seems to be named after the appearance of their caterpillars. The moths themselves are short-lived. The caterpillars of many kinds of Tussock Moths (especially the notorious Gypsy Moth) feed ravenously on leaves of trees and bushes, including oak trees which are otherwise rather insect resistant.

Classic Car

Bonnie-and-Clyde-classic-car-folsom-20190511-19

One week ago at the Winco parking lot in Folsom I spied this car, and snapped a photo. It was not until after downloading the photo that I noticed several bullet holes (I presume fake) on the door panels. It turns out this car is very similar to the Ford (stolen) that Bonnie and Clyde were killed in while driving through Louisiana. I can only guess that the “bullet holes” are there in commemoration of that event. I am also guessing on the engine size, but this type of car could hold a large V-8 engine and was popular for its power and speed.

CCHR Marches Against ECT

CCHR-march-SF-20190518-28

Instead of my usual trip to Folsom on Saturday, I went to San Francisco to participate in a March supporting a ban on ECT. It rained the whole time we were there. CCHR stands for Citizens Commission on Human Rights, a group established by the Church of Scientology in 1969.

Psychiatrists still think that inducing convulsions (seizures) in the patient is a valid form of therapy. They (or their predecessors) have been doing this to their patients for roughly 500 years. As soon as electricity became widely available, they began to use it for this purpose. Electroconvulsive Therapy (ECT) became widely used in the U.S. a little less than 100 years ago. It is still quite widely used.

Wikipedia states that the ordinary shock “dose” is about 0.8 amps for between 1 and 6 seconds. It is widely known in the occupational safety community that a shock between the hands (or from a hand to a foot, etc.) of this amplitude and duration would cause burns, death or a heart attack, as well as severe pain. Psychiatrists apply this across the head or to one side of the head, and anesthetize the patient (except in a few countries, per one report) so that he or she will not be aware of the pain. They report “swift results” from this procedure.

Of course, they are not trying to make people well; they are just trying to make them quiet. What sort of persons or groups would prefer quiet people to happy people? These are the ones who support the work of the psychiatrists. The rest of us avoid them as much as we can, if we are aware of the destruction which they routinely cause. By best estimates, over 1 million people planet wide each year receive this “treatment.” About 10% of those live in the U.S. Ages range from babies (literally!) to seniors, but especially older people and women. Meanwhile, the World Health Organization recommends that ECT on minors be banned, citing no evidence of benefit.

From what I have learned about psychiatry over the years, I consider their leaders and spokespersons to be a pack of raving lunatics; criminals. They assisted greatly in the development and continuation of racism in the United States, they enthusiastically forwarded the “man is an animal” notion that helped make modern war and anti-religious fanaticism OK in the early 1900s, then helped the Nazis establish their death camps before and during the second World War, supported Apartheid in South Africa and segregation in the U.S. and have more recently unleashed the tragedy of psychoactive drugs on this planet. For me there is no alternative to the total abolition of psychiatry on this planet. We will get around to other planets as soon as we can.

Dial Two

4 May 2019

This is my third project in the “dial” series. See Dial One here.

With this project I wanted to try out a few design options, and I concentrated on those.

Though it is still far from a thing of beauty, the more minimal enclosure, featuring primarily the dial itself, was one thing I wanted to try. There was plenty of room for the electronics, and a nice big dial, but putting the power supply in the box seemed not possible. This is not necessarily a big problem, as the system also requires a sensor, or signal source box, and this could supply the power.

dial_two-20190430-88-cropped

The dial itself is irritatingly green, but in a more finished version, that board could be painted black. For the “featured” photo I adjusted the color balance to fade the green down.

16 steps

The other feature I wanted to try was a 16-step dial.

For this design I abandoned the idea of scanning the dial, which meant inventing a significantly different way to get the dial pattern to move around. Each step on the dial is on or off depending on a latch which stores that value for one cycle of 16 steps. Each latch gets its data from a common signal line, but the time when the data is transferred is different for each latch. In that way, the signal – which carries the pattern – can be time-delayed relative to the scanning pulses, thus updating the position of the “pointer” for every 16-step cycle.

Lights and Colors

To keep things simple, I used one circle of white LEDs. But this does not seem very aesthetically pleasing. I need to find colors that will work better. There is also no fading built into this design; the lights are either full on or full off. More control over light intensity seems desirable here. My next design will address these issues.

dial_two-20190430-98-slightly-lightened

This photo was made under very low-light conditions, then brightened slightly with digital manipulation. But this only slowed down the camera enough to show three lights on at once. I am considering making videos of my projects. That would give you a better idea of how they look “live.”