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  1. Externet

    Renewable Energy (part 2)

    What voltage and amperage are you aiming to ? For what purpose ? Charging an automotive battery ? Find a discarded thread mill and use its permanent magnet DC motor as generator. Run it at the highest rpm you can.
  2. Externet

    New LEDs from 0.8V !

    Periodically I receive information about new products directly from manufacturers. The latest one are LED 'bulbs' that run from 0.8V to 1.8. Yes, white too. :eek: At the end of list, Part number starts with OBD3 : ----> http://www.optosupply.com/EN/product_list2.asp?sid=121&bid=158&i=2&pdid=2&...
  3. Externet

    Mechanism disassembly

    Plan B. Hammer under the clip a knife and twist. Or insert a flat screwdriver as soon as there is any gap under. Plan C. Grab the outer edges of the clip with plyers and deform it squeezing.
  4. Externet

    It is designed to run off of 12VDC, I would like it to run off 24VDC

    Install a 7812 regulator in series to D2.
  5. Externet

    Mechanism disassembly

    Fit a tiny flat screwdriver in a radial gap and pry open as suggested above. By the second or third gap it will release.
  6. Externet

    Solar Powered Phone Charger

    Six volts panel should be enough, and cannot find now the ones to adhere in the back of a cell phone. Perhaps discontinued. The ones I see now are ----> http://www.inhabitat.com/wp-content/uploads/samsungsolarphonewow.jpg and ----> http://www.geekalerts.com/solar-iphone-battery/ and ---->...
  7. Externet

    What breaks when you "gently" drop something?

    First suspect is a broken resonator (or crystal) by its processor. Check with an oscilloscope for an active clock. Second : key button stuck down. Pound/shake the keyboard to try to dislodge something caught where should not be.
  8. Externet

    Blowing a 3A fuse with an AA battery?

    If the fuse does not melt, the energy contained in that AA cell is not enough to reach 3 Amperes for the lenght of time needed for melting. Can be a cheap cell, a depleted cell, a poorly connected cell...
  9. Externet

    Does this switch exist!?

    Yes, such switch does exist, mostly in antique devices like telephones and relays. A combination of 'make-before-break' and 'normal' type of contacts can also achieve such. A modified pushbutton can do it if the contact happens half way in its travel. Open at rest, and open when fully...
  10. Externet

    Electronic power and resistance rules

    Adding these ----> http://i588.photobucket.com/albums/ss323/Innernet/Triangles.jpg I believe they are correct. If not, advise please.
  11. Externet

    Power Capacity of Resistors of Different Values

    That is my impression. Resistor power ratings are added if the resistors are either in parallel or in series, for equal resistance values. Your number 2 does not have equal value resistors, should not apply. Some resistors are wirewound or of helical construction. Those contribute also with...
  12. Externet

    What is this part?

    It is an educational (or not) electrolysis cell ----> http://www.chescientific.com/edu/company/Griffin%20Education/f154593a-6cb9-479d-b8d3-d5e71e41c71aEKY-400-T.jpg
  13. Externet

    Frequency Detector

    The NE567 works very well and reliable, for sinewaves. A 555 outputs square or triangle waves and will not yield a very stable detection. I have not found a monolithic sinewave generator IC. Somehow they are not built. It would be nice to set a capacitor and variable potentiometer on a chip...
  14. Externet

    audio transformer

    Something to do with that transformer... Connect the 0.62 ohm winding in series to only one telephone wire. At the other 70 ohm winding, you can inject audio, background music, or record a conversation from the line.
  15. Externet

    In-wall wiring detector

    The first link is not radar, even if named that way. The second will not penetrate walls. Keep present that many responses are not considering stone or concrete walls with metal or not ducts housing the wires, as the only building methods they may know of are paper, plaster and wood sticks...
  16. Externet

    LED Light with dusk to dawn function

    There is hundreds of these at many stores: ---> http://www.maxximastyle.com/led-night-lights/led-night-light-with-dusk-to-dawn-sensor-and-frosted-lens?gdftrk=gdfV27260_a_7c855_a_7c2335_a_7c14&gclid=CPrems-Xn7wCFe1aMgodCnEAfw#.UubAPM9Onrc If you want it smaller, canibalize its guts discarding...
  17. Externet

    Limiting car audio volume

    It would be more like ~20 ohm resistor in series to each speaker. Until he finds out and bypasses them
  18. Externet

    Automotive gurus

    Thanks for clarifying about the new types. Well, then the switch method would not fake a PWM; just do the manual on/off.
  19. Externet

    Automotive gurus

    The torque converter clutch TCC is engaged by a solenoid; there is no pulse modulation mode I know of. It is either energized or not. A plain switch should be capable of controlling such. I made two circuits and installed them in my 2 classic cars, they engage TCC at about 45 mph, with a...
  20. Externet

    New guy - need a block heater for Evinrude

    To warm up that motor, if 120VAC is available at dock/garage; leave a 100W bulb on under the hood a couple of hours before starting, or all night.
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