Sunday, October 30, 2011

Wittewater Church


Last week I visited the Wittewater Moravian Church (pictured), which lies some 100 miles north of Cape Town. The gospel was first preached here at a spot just off the right of the photo, by Rev. J.W.A. Stoltz, in 1859. The Church was built in 1911. Compare this with the neighbouring Goedverwacht Moravian Church.

Thursday, October 27, 2011

Giving Plants A Voice

The next concept I wish to tackle electronically is a a device which I hope will give the plant kingdom a voice -- to turn plant "emotions" into sound. I previously did experiments in this line, which were partially successful -- but I found that plant "voices" ran too wild -- they went "off the scale". They would speak for a while in tones and semitones, then suddenly in multiple octaves. OBSERVATION: As soon as I give the plants of our planet a voice, human voices, for the first time in history, will be in the minority. Also, humans will finally appreciate what they have been doing to plants' emotions by eating them. But seriously, who wouldn't want to hear their pot plant talk? (I previously monitored voltages in plants, and used a voltage-to-frequency converter to enable them to "speak").

Saturday, October 22, 2011

Comeback Trail

I've been on the comeback trail with electronic design. At the beginning of this week, I reported that I was developing a magnetometer. Yesterday I submitted the design for publication. It was snapped up in 11 minutes flat, by the UK's top electronics magazine. That must be a record for me. It is scheduled to appear in the new year. OBSERVATION: (I wish this would happen to my theology!)

Wednesday, October 19, 2011

Flashback 1967-1968


This is a recent photo of the islets of Abaiang, which lie on the northern side of this remote Pacific atoll. During 1967 or 1968, I lived on one of these islets (Nuotaea -- not pictured), as well as on the south side of the atoll, at Morikao. Every day, we swam in these waters. In 1993 and again in 1998, I visited the south side of Abaiang.

Tuesday, October 18, 2011

Designing

I frequently receive electronics mail -- that is, from electronics students or enthusiasts asking for advice. What strikes me again and again is that people who need to do electronic design want to know exactly which component to place where and why before they place it. My own secret to design success is a) to work in an intuitive "haze" without really thinking, and b) to do this with (often) "live" circuits in front of me. If that doesn't bear fruit, I stop and focus on the science -- then do a) and b) again. OBSERVATION: This not seldom leads to blow-outs -- my biggest blow-out having caused me thousands of rands (hundreds of dollars) worth of damage in a split second. Typically, if I have a design intuition, I'll buy several of the same components so that I won't be stopped if one blows out. Yesterday, as an example, I blew out a CMOS 4069 (R5 / $0.5o each).

Friday, October 7, 2011

BFO Metal Detector

I did some designing this week. Here's a spin-off of my experiments. It's a beat frequency operation (BFO) metal detector -- and a good one -- for BFO. It is able to detect an old Victorian penny at more than 100mm. It is based on a novel 555 LRC oscillator. Note that the 555 IC must be a CMOS version, such as the ICM7555 or the TLC555. Instructions for winding the coil L1 may be found at BFO Metal Detector [2]. The output is taken via a wire to a MW radio aerial, and the radio is suitably tuned, to find a good heterodyne. It's a nice, simple project for entertaining a child. One may experiment with the value of R1 to tweak sensitivity. OBSERVATION: This may easily be turned into a self-contained BFO metal detector. A similar circuit is twinned with this one, only with an 820ยต inductor for L1, and a 10k multi-turn potentiometer for R1. A crystal earpiece is wired between the two outputs. . NOTE: You may re-publish this design, on condition that you acknowledge the designer (Thomas O. Scarborough).

Wednesday, October 5, 2011

Fresh Design


Friends have been urging me to do some fresh electronic design. So, a fortnight ago, I fired up an oscilloscope for the first time in a year or two (one can "see" into circuits using an oscilloscope). Then I designed a novel four-component LRC oscillator, as the basis for a metal detector. Progress looks good -- but I have lost the "drive" to do this. The photo shows the oscilloscope probe.

Sunday, October 2, 2011

Flashback 1983


I took this photo of wife Mirjam standing before the legendary Mukorob, or Finger of God, in 1983. The Mukorob collapsed five years later. According to Nama tradition, its collapse would mark the end of the power of the White man in Namibia. So it did. The Tripartite Agreement was signed eighteen days later. You may click on the photo to enlarge to 200k.