http://wiki.waggy.org/dokuwiki/ 2010-04-18T13:34:52-04:00 http://wiki.waggy.org/dokuwiki/ http://wiki.waggy.org/dokuwiki/lib/images/favicon.ico text/html 2008-04-24T13:45:10-04:00 http://wiki.waggy.org/dokuwiki/electronics/components?rev=1209059110&do=diff Electronic Components On-hand These are some of the components available for testing. TypicalTypeNominal (pF)Drive MinMax Air 365Direct Air 3818:1 Planetary 14 400 Air 320/3806:1 Vernier Air 320/14.7/380/14.73:1 Vernier 12/9/12/9345/25/405/25 Air 480/5056:1 Vernier 8/8 520/500 Plastic 60/160Direct 84 184 Plastic 266/266Direct Piston, Hi-Q 1-25Direct … text/html 2008-03-21T14:55:07-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystal_earplug?rev=1206125707&do=diff Crystal Earplugs and Piezo Elements For use with a Crystal Radio --- David Wagner 2007/11/02 00:11 Modern ceramic piezoelectric earphones seem to have the following characteristics. 1M 5u4 \ / VVV-------+--||---[]--+ | | | | 27m | | +--UUUU--+ | | ==== | | | | | >---VVV VVV----------+ 1M 1M | | o---------------------… text/html 2008-03-16T14:20:54-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystal_fm?rev=1205691654&do=diff A Crystal FM Radio --- David Wagner 2008/02/20 00:06 The wp>FM broadcast band is about 87.5 to 108.0 MHz (550-680 Mrad/s), with a geometric mean of 97.2 MHz (610 Mrad/s), and 200 kHz channel spacing. FrequencyWavelengthλ/2 (MHz) (rad/sec) (m) (in) 87.5 550,000 3.426 67.4 89.8 564,000 3.337 65.7 92.2 579,000 3.251 64.0 94.7 595,000 3.166 62.3 97.2 611,000 3.084 60.7 99.8 627,000 3.004 59.1 102.5 644,000 … text/html 2008-02-20T00:02:04-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystal_nwr-notes?rev=1203483724&do=diff Crystal NOAA Weather Radio (NWR) Notes --- David Wagner 2007/11/21 16:37 In the US, the National Oceanic and Atmospheric Administration (NOAA) broadcasts FM weather information in the VHF range. 162.400 162.425 162.450 162.475 162.500 162.525 162.550MHz 1.84601 1.84573 1.84544 1.84516 1.84488 1.84459 1.84431m 72.6777 72.6665 72.6553 72.6441 72.6329 72.6218 72.6106in A crystal radio is considered a high-impedance load, and seems to work best with a high-impedance anten… text/html 2008-03-16T14:22:48-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystal_nwr?rev=1205691768&do=diff Crystal NOAA Weather Radio (NWR) --- David Wagner 2007/11/21 16:37 * Crystal NOAA Weather Radio (NWR) Notes In the US, the National Oceanic and Atmospheric Administration (NOAA) broadcasts FM weather information in the VHF range. 162.400 162.425 162.450 162.475 162.500 162.525 162.550MHz 1.84601 1.84573 1.84544 1.84516 1.84488 1.84459 1.84431m 72.6777 72.6665 72.6553 72.6441 72.6329 72.6218 72.6106in San Antonio weather is broadcast at 162.550 MHz, WXK-67, 1000 Wa… text/html 2008-02-01T21:00:11-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystalradio-model?rev=1201917611&do=diff Crystal Radio Modeling --- David Wagner 2007/10/05 14:27 * * * Component Voltage Drop v(i)dv/dt Capacitor Resistor Inductor Diode Diode with Series Resistance “Some diodes, especially germanium and silicon junction diodes seem to have Is and n values which increase at very high currents (higher than those usually encountered in crystal radio set operation). In some of these diodes, the values of Is and n also increase at very low currents, harming weak signal receptio… text/html 2008-04-29T10:33:54-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystalradio-old?rev=1209479634&do=diff Crystal Radio Notes Archive --- David Wagner 2007/09/25 00:12 * * * * * * \|/ | Tuggle Antenna Tuner | ........ | / / | +--||--+--||------+ | | / | / | | | | --- +--UU--+--+-UUUU-+ - = = +-UUUU-+ +-UUUU-+ | | | Tank | | / | | / | +--||--+ +--||--+--------------+----+ / | / | o Wave | +--… text/html 2007-10-14T00:36:15-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystalradio-thoughts?rev=1192336575&do=diff Thinking about Crystal Radios --- David Wagner 2007/09/13 00:50 First, consider how a radio wave at some frequency (say 1MHz) will typically induce a tiny alternate current at some moderate voltage (perhaps 10-40V peak-to-peak) in an antenna. Now think of a typical resonant LC circuit driven by the antenna current. This 'tank' circuit stores more than one cycle of an exciting wave before it is charged enough to be 'full' and begin to overflow energy through the diode. The resonant circu… text/html 2008-03-08T18:30:59-04:00 http://wiki.waggy.org/dokuwiki/electronics/crystalradio?rev=1205019059&do=diff Crystal Radio --- David Wagner 2007/09/11 08:46 Useful links * Excellent summary from VE7SL * Dave's Crystal Radio Sets My Stuff * Electronic Components On-hand * Crystal NOAA Weather Radio (NWR) * Crystal Earplugs and Piezo Elements notes * Crystal Radio Modeling * Thinking about Crystal Radios * Crystal Radio Notes Archive text/html 2007-08-30T01:04:55-04:00 http://wiki.waggy.org/dokuwiki/electronics/joulethief-archive?rev=1188450295&do=diff Archive of Jewel Thief Stuff I'm just dumping stuff here I may need later. --- David Wagner 2007/07/13 00:14 Alternative Schematics // +------+ +-------+-->|-+-----+ | | | | | | A1 UUUUU.A2 + _+-----+ | ===== C\ /E | | B2.UUUUU B1 ----- | | | | |B | +------+ +--/\/\/---+ | | | | --- +----> +1V - … text/html 2007-08-29T12:11:48-04:00 http://wiki.waggy.org/dokuwiki/electronics/joulethief-notes?rev=1188403908&do=diff Random related thoughts. The amperage to the load depends on the load's impedance and the input voltage. Making some meters. <http://campus.udayton.edu/~physics/gkm/p207ch28.htm> * Ig=250 uA galvanometer max deflection current * Rg: galvanometer resistance text/html 2007-09-12T12:33:52-04:00 http://wiki.waggy.org/dokuwiki/electronics/joulethief-parts?rev=1189614832&do=diff Selecting Joule Thief Components --- David Wagner 2007/07/07 10:33 // +-->|--+ | | +------------------------+-->|--+--||--+ | | | | | ======= |/ C +--Z<--+ +--UUU+UUU--+-/\/\/-+--| | | | B|\|E | | | +-------------+ | | | | +… text/html 2008-05-19T21:33:13-04:00 http://wiki.waggy.org/dokuwiki/electronics/joulethief-solar?rev=1211247193&do=diff The Sun Thief --- David Wagner 2007/08/29 12:18 Switched Solar Charging Most of the same components used to run the LED can also be used to charge a NiCd or NiMH cell by using one or two solar cells in series as a power source and replacing the LED with the battery cell. To use a single solar cell as shown, select a germanium transistor so the circuit will work and be sure to use a Schottky rectifier or larger germanium diode to minimize output power losses. Though tests have been inconcl… text/html 2007-11-07T12:50:14-04:00 http://wiki.waggy.org/dokuwiki/electronics/joulethief-tests?rev=1194457814&do=diff Joule Thief Testing I have done hundreds of tests of this circuit in various configurations. * Electronic Components On-hand * [Set 1] * [Set 2] * [Set 3] * [Set 4] FIXME Is the following any good? Without a zener diode in place to protect the LED, the safest way to measure the efficiency is to determine the LED and diode's voltage drop and assume their reverse current leakage losses and the capacitor's losses are negligible. Then measure the current at two places: the coil's c… text/html 2007-08-29T12:11:25-04:00 http://wiki.waggy.org/dokuwiki/electronics/joulethief-variations?rev=1188403885&do=diff Joule Thief Variations --- David Wagner 2007/07/16 09:04 This circuit is for making two joule thieves entirely by salvaging the parts from one CFL. The diode at the base of the transistor is there to limit the “on” time of the transistor if the base resistor value is too small (<1kΩ). text/html 2010-01-09T15:48:43-04:00 http://wiki.waggy.org/dokuwiki/electronics/joulethief?rev=1263070123&do=diff Joule Thief This fascinating circuit steps up tiny DC voltages to more useful levels using only a few parts easily scavenged. // +-->|-------+ | | +------------------+ _+-----+ | C \ / E | | 1:1 BC547 ----- | | = = = = |B | +--UUU+UUU--+--/\/\/--+ | A2 | B1 1k | | | | +-----------… text/html 2008-02-02T13:05:32-04:00 http://wiki.waggy.org/dokuwiki/electronics/lrc-frequency?rev=1201975532&do=diff LRC Network Frequency Response --- David Wagner 2008/02/02 12:37 The procedure to calculate the frequency response of an arbitrary LRC network can be simplified. * Construct L, R, and C matrices representing the properties between every node. Thus R1,2 is the resistance between nodes one and two. * Construct a matrix Z_f representing the impedance between each node at a given frequency * The impedance between each node is the parallel combination of the impedances of L, R, and C at … text/html 2007-08-29T12:10:51-04:00 http://wiki.waggy.org/dokuwiki/electronics/manurefuelcell-wrong?rev=1188403851&do=diff The following is incorrect Biological processes chemically reduce the manure, lowering its pH and producing an excess of hydronium ions(H3O+). Since there is a greater concentration of hydronium on the manure side of the cell, osmosis drives these ions (or just their excess protons) through the membrane and into the neutral weak brine. Similarly, hydroxide ions (OH-) are driven from the brine into the manure, though at a lower rate. text/html 2009-07-14T12:39:01-04:00 http://wiki.waggy.org/dokuwiki/electronics/manurefuelcell?rev=1247589541&do=diff A wp>microbial fuel cell uses anaerobic biological decomposition of organic matter to produce electricity. The salt solution can also draw excess water from the anaerobic chamber, and controlling evaporation from the brine will control the moisture level of the decomposing material. text/html 2007-08-29T12:13:20-04:00 http://wiki.waggy.org/dokuwiki/electronics/micropower-kit?rev=1188404000&do=diff Power Sources Solar Cells (or bag of broken cells)1Peltier Junction Copper and Zinc Plates Graphite (for Electrodes) DC Motors (For turbines) Magnet Wire (30 gauge?) Rare Earth Magnets Meters 2Voltmeters2Ammeters Loads