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  1. Externet

    Considerations to make this contraption work ?

    Hi. Made a block diagram sketch as shown below. Intention is to have the LED fully energized only during the rising of the 1Hz sharkfin waveform until it reaches 2.5V level, and off when the waveform at 'C' decreases by the comparator discharging it. And the coil proportionally energized with...
  2. Externet

    Snap action night light...

    What considerations should be taken to build a dusk-to-dawn switch that will turn fully on abruptly at dark instead of gradually ramping on ? I prefer to use a phototransistor and a mosfet. No LDR, no transistor. Will turn on a tiny 3V motor, no leds.
  3. Externet

    Shutter Glasses

    Welcome. You can reach me via email at my username at inorbitdotcom, or direct messaging. ----> https://www.electro-tech-online.com/threads/rapid-alternating-occlusion-glasses.153653/#post-1324900 Post 9 at ---->...
  4. Externet

    Microphone advise for monitoring heart sounds in animals under anesthesia

    Welcome. An electret microphone tight fitted at the end of the stethoscope tube will be extremely sensitive to sound and anything touching/rubbing the tube. An audio preamplifier for it is commonly available. Is your current microphone tight fitted inside the tube end ? The length of the tube...
  5. Externet

    Visible light

    The transmitter that transmits a signal at the frequency of light, will be a PN junction like a LED or laser. The human eye will see the light emitted, but it is not called antenna, it is a light emitter.
  6. Externet

    Reducing music in videos

    Just incompetent audio engineers, trying to be impressive and impacting in their work, trashing the production. I called/messaged three or four times to the production companies shown at the credits end of documentals/movies to spank them and about half of times has worked, with more...
  7. Externet

    Magneto kill terminal...

    I believe the B&S magneto has no active components; just the coil windings. The flywheel magnet passing past the coil collapses the magnetic field kicking the spark generation.
  8. Externet

    How do I boost a TV antenna amplifier to bring in weak signals?

    You will get better results and less complications and expense with another antenna at the new location. Make the antenna. You will find all the unpredictable reception could work better with a coat hanger than with a expensive antenna. For UHF, make a loop and hang it high. Amplifying a weak...
  9. Externet

    Magneto kill terminal...

    OK. That is the key !
  10. Externet

    Magneto kill terminal...

    Thanks for your elaborated and dedicated response, debe. OK; about 110V peak unloaded. These schematics shows that when the primary is grounded/shorted by the switch, the engine turns off, as the passing flywheel magnet 1 does not produce spark in that condition. Primary and secondary are not...
  11. Externet

    Magneto kill terminal...

    Hi Bob. That cannot be. Would put high tension to the keyswitch while running in order to be grounded when keyswitch turns off. It is about a wire coming out of the magneto which is not high tension, grounded by a lever if operator releases grip of a push mower or turns key off on a riding mower.
  12. Externet

    Magneto kill terminal...

    How does it work ? Grounding it kills spark to shut down an engine like in a lawn mower. What is the potential on that wire when running ? Or, is there many flavors ?
  13. Externet

    3D printer for replacement plastic parts?

    Pardon my spoon in your plate; just saw yesterday on a Japanese TV channel they invented this pen: ----> Enjoy.
  14. Externet

    Garden lights working on 18650 lithium single cell...

    Thanks, Audioguru. I will then investigate further to find an application note for the 5252F as you mentioned, without the inductor. Or will have to buy one and check how is it wired. Seems like without the inductor, that IC will only work as light sensing and turning the load on at dark, the...
  15. Externet

    Garden lights working on 18650 lithium single cell...

    Thanks. Yes, that second circuit seems wrong. The paralleled LEDs is obviously goofy. Checked the 5252F data sheet and does not show useable with lithium cells... For a 5.0V weak panel perhaps after a diode... Such chip is to boost 1.2V to the LED Vf. A chip fed by 3.x to 4.2V from single...
  16. Externet

    Garden lights working on 18650 lithium single cell...

    Something wrong, one did not attach? Images borrowed from the web.
  17. Externet

    Garden lights working on 18650 lithium single cell...

    The common variety of solar garden lights use a dedicated four pin IC to manage operation. Is there a similar single IC for garden lights that use a lithium cell ? Or modifying one to handle a 5V panel and a lithium cell ? Edited. Sorry, goofed by not searching first... The complex and the...
  18. Externet

    14.4 V Lithium battery - re-purposing question

    Typically, in the battery end there is a power terminal for charging, sometimes there is a diode to ensure it is never fed in reverse polarity that would destroy the charging management circuitry; another for power delivery to the tool, another power common, another temperature sensing that tell...
  19. Externet

    Solenoid Piston help

    Welcome. Enjoy some ideas... ----> https://duckduckgo.com/?q=solenoid+engine&t=canonical&ia=videos
  20. Externet

    Window mode on scope

    Check the oscilloscope manual for features and options.
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