Search results

Search Forums New Posts
  1. Externet

    Lens info needed

    Imagine you already have in your hands 3 or 4 lenses. How will you mount/held them perfectly aligned and properly spaced... That is the hardest part. Try to locate an used one; will be cheaper than choosing/buying lenses and housing to hold them properly. ---->...
  2. Externet

    How can µF-range capacitors reduce AC voltage?

    Hello KrisBlueNZ. I have seen schematics like the one on your post #12 many times and places on the web. I do not understand why the components D5, D6, D7, D8 are not fully erased/deleted from the circuit; and make D1, D2, D3, D4 the LEDs instead. Same for the original poster circuit, no C1...
  3. Externet

    Where to buy contact pads for silicon buttons?

    The best friend for elastomeric contacts is a pencil. The graphite can to a point, recoat the 'buttons', and the eraser, clean the etched traces. If unhappy with the pencil treatment, cut tiny aluminium foil rounds and glue them on top of the carbon pads.
  4. Externet

    making a tiny heat element

    Complexities, complexities... ----> http://i.ebayimg.com/00/s/NTAwWDUwMA==/z/Z0oAAOxyn~pR3sQ9/$%28KGrHqZ,!qgFHJYIhmz!BR3sQ8uq+w~~60_35.JPG?set_id=8800005007
  5. Externet

    Electronic Compass - Help Needed

    Check if the candy store has one that you can choose : ----> http://www.dx.com/s/electronic+compass
  6. Externet

    making a tiny heat element

    If you do not unscrew the heating element, the socket and the whole car dash is needed. ----> http://www.pelicanparts.com/catalog/images/new_images2/cigarette_element.JPG
  7. Externet

    Magnetic Pickup Unit (MPU)

    Can be a plain stepper motor driven as generator. They are three phase.
  8. Externet

    Cleaning Keypads on Electronic Musical Keyboards and Similar Keypads

    You must have access to the contact surfaces to restore/clean them. One by one. The best friend for repairing those keypads is a pencil. Its eraser cleans superbly as it is the finest type of 'sanding paper' Rubbing the graphite tip to worn out spots can restore continuity to them. When the...
  9. Externet

    making a tiny heat element

    Just pass the nylon string a couple of millimeters in front of (or nearly rubbing) a plain automotive cigarette lighter. It works on the 12V you have, and you will not have the trouble of properly bonding (crimping) the heating element to the wires. If you want to consider another option, a...
  10. Externet

    Help with aerial for channel 38

    Great to see the hurricane-proof version. Congratulations !
  11. Externet

    Looking for a suitable transmitter

    For heartbeat rate transmission, and no other data, sound can be used at any audible frequency. Clicks as dolphins do would be very effective. A single click or tone burst every beat, by using a proper transducer. The attenuation would be very low at 15 m. Even a plain miniature noisy relay can...
  12. Externet

    Heatsink material question

    Why is the concern ? Obviously yes, there is other than aluminium material.
  13. Externet

    Looking for a suitable transmitter

    For only 15 metre range, I would use any light transmission, omnidirectional LED or laser directional. Will take minimal power and the emitter can be a square millimetre. Hope the water is clear. Like a TV remote control, no buttons. Just the wrist heart rate sensor modulating and powering the...
  14. Externet

    Help with aerial for channel 38

    Hey Miguel I strongly suggest you build a loop for 616 MHz. It will be ~300 ohm but do not pay attention as the modern TV tuners do not know that. I just made one after sick and tired of marginal reception on 516 MHz with a stupid telescopic rod. Now the 8 inch loop is performing great. I...
  15. Externet

    Anyone able to help me out for my invention?

    There is many unknown particularities to your solenoid, its characteristics, the supply you are using, the time you want it open in order to suggest a decisive way. But try a 'large' capacitor in series with the solenoid. There will be a value that should work. A resistor of an unknown value...
  16. Externet

    LED lighting without power source

    Happens to me too. Twice. And have no explanation. My house has plain normal electric 120VAC wiring, and no high tension nearby. No RF sources in the middle of a forest. Indoors. My LED night lamp faintly glows with the switch off all the time, hot or cold, humid or dry... A hallway ceiling...
  17. Externet

    Projects to help a beginner learn?

    Get one of these : ----> http://www.vetco.net/catalog/default.php?cPath=523_525
  18. Externet

    Connecting Li-ion cells in series

    My two laptops battery packs have factory paralleled 2 Li-ion cells times 3 series; My electric drill has paralleled 2 Li-ion cells times 4 series for 16 V; My ATV has four paralleled Li-ion times 3 for 12V instead of lead acid. They do not have a hiccup. All 18650 cells. ---->...
  19. Externet

    Connecting Li-ion cells in series

    Why ?
  20. Externet

    solar phone charger

    Stick one at the back of your phone ----> http://www.ebay.com/itm/PowerFilm-SP4-2-37-Flexible-Solar-Panel-Cell-4-2v-22mA-/281097190170 ----> http://ecx.images-amazon.com/images/I/51QZbwGYZjL._SY300_.jpg ---->...
Top