speleogroup.org
Speleogroup - lamptest2003
http://www.speleogroup.org/lamptest2003.html
Luxeon LED caving lamp tests. Speleogroup is experimenting with circuits for driving high-power LED devices, such as the White LED Luxeon Star from Lumileds. This device is rated at approximately one watt, giving typically 18 lumens at its rated current of 350mA. Their high dome Amber Luxeon star gives 36 lumens at a similar power, with a colour close to that of a sodium street lamp. In July 2003 we tested a number of these lamps, using various conversions and drives, in real caving conditions in Spain.
speleogroup.org
Speleogroup - lt1512a
http://www.speleogroup.org/lt1512a.html
Luxeon LED caving lamps – LT1512 SEPIC solution. Speleogroup is experimenting with circuits for driving high-power LED devices, such as the White LED Luxeon Star from Lumileds. This device is rated at approximately one watt, giving typically 18 lumens at its rated current of 350mA. This page describes one circuit we’ve developed, using the Linear Technology LT1512 chip, a current mode switching regulator. A later design. The LT1512 chip, from Linear Technology. This means that many combinations of batter...
speleogroup.org
Speleogroup - ISPisolate
http://www.speleogroup.org/ISPisolate.html
AVR STK500 ISP isolator circuits. While developing a circuit for driving high-power LEDs, using the Atmel. AVR RISC ATTiny15L microcontroller. We discovered a flaw in the AVR STK500 starter kit; the three lines providing in-system programming (ISP) are permanently connected to the microcontroller (PB0 through PB1 on the ATTiny15). The buffer can be built on a PCB or small piece of stripboard and included in a 6-way cable which replaces the usual jumper cable between ISP6PIN and (in our case) SPROG1.
speleogroup.org
Speleogroup - sg1983
http://www.speleogroup.org/sg1983.html
Expedition log, Summer 1983. A transcription of the Speleogroup logbook. La Franca first, then Llanes. Purón, etc. Bill potters around Castro Urdiales, etc. Until Mike arrives at Bilbao airport (17:20). Drive west, stopping for a tinto. At Santillana. Decided to drive on: arrived at La Franca campsite 22:30, to El Horno for dinner at 23:00. Finally back to the campsite for a late meal (garlic with bonito. And a stroll down to the sea. Up at 08:00 again(! After leaving a copy of [Toyu? 93; survey in the b...
speleogroup.org
Speleogroup - sg1979
http://www.speleogroup.org/sg1979.html
Expedition log, Summer 1979. A summary and index of the Speleogroup logbook. Los Lagos in the wet, Cueva Toyu. Garma Ciega surface measurements, etc. First appearance of barometric altitude data in logs. Heathrow to Bilbao for Mike, 1 hour 20 minutes: customs more thorough than usual on arrival. Into Castro U. for a good dinner: soup, hake in a green (pea) sauce, veal steak, flan. 2 bottles wine; all for 425pts each (less than 3.00). Staggered down v. steep path to tents. A couple of beers and a few hand...
speleogroup.org
Speleogroup - sg1973
http://www.speleogroup.org/sg1973.html
Expedition log, Summer 1973. BUSS in La Hermida, 1973 (click for larger). Members of Speleogroup traveled to Spain as part of the the Birmingham University Speleological Society (BUSS) and Oxford University Cave Club (OUCC) expeditions. Currently no logbook for this expedition has been located; however, the expedition reports of the two expeditions, OmniBUSS 5. And OUCC Report 1973. Are now available online. August 28 –. La Hermida Gorge and surrounding areas. Details in OmniBUSS 5. And OUCC Report 1973.
speleogroup.org
Speleogroup - sg1977
http://www.speleogroup.org/sg1977.html
Expedition log, Easter and Summer 1977. A summary and index of the Speleogroup logbooks. 1977 saw two Speleogroup expeditions to Spain; one, a reconnaissance expedition at Easter. And the other (objective the Sima de Garma Ciega. Temporary headquarters: St. Georges Drive, London. Expedition launched with Taylor’s ’71 Special Reserve. Some hours flight delays, Bilbao at 18:30. A wet Castro Urdiales and meal at Paris. Camped above cave at 01:30. But more water than Porth yr Ogof in flood and pitch far too ...
speleogroup.org
Speleogroup - sg1976
http://www.speleogroup.org/sg1976.html
Expedition log, Summer 1976. A summary and index of the Speleogroup logbook. This expedition, Forcau 76. Was organized by Speleogroup and the Oxford University Cave Club, and had as its objective the Pozu de Vega El Forcau. Now shown on Picos de Europa maps, 2km SSE of the sorthern tip of Lago de la Ercina, 30T 340.39 4790.42. Alt 1480m). This was partially explored by Speleogroup in 1975. With the French club SCAL. See the expedition report. See the personnel list. Aznar Line). MC BC DT ST. Up to Forcau...
speleogroup.org
Speleogroup - sg1974
http://www.speleogroup.org/sg1974.html
Expedition log, New Year 1974/75. This expedition was not logged at the time, so the following paragraphs are largely from memory.). Departure date was 27 December 1974; the ferry company cancelled our daytime trip to Le Havre but gave us a free cabin on the overnight passage! Very welcome. Long drive in the three-wheeler down through France. We attempted a survey of Tinganón. Using a protractor as an clinometer (which Bill still has, in 2007! We went down Rales cave. And surface explorations, etc. See a...
speleogroup.org
Speleogroup - sg1985
http://www.speleogroup.org/sg1985.html
Expedition log, Summer 1985. A transcription of the Speleogroup logbook. La Franca, Fuentica. La Hermida/Bejes, Los Lagos, Llanes etc. The expedition gets off to an inauspicious start when Bill’s car is broken into in Milan just before he leaves Italy. Last-minute shopping expeditions on both side of the Channel manage to replace most of the stolen gear, however, and both arrive at Bilbao on schedule and properly equipped. Surprisingly) up at 08:00(! To delay things, somewhat, we have a look over nearby ...
