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  1. Externet

    What is this resistor? Help

    Looks like 1 Watt to me.
  2. Externet

    Measurement device

    Something has to vary along the measuring span. Then read the instantaneous value. Explore 'sample-and-hold' circuits : ----> http://mysite.du.edu/~etuttle/electron/elect25.htm
  3. Externet

    Any Linux (specifically Ubuntu) users here? HELP!

    Running only Ubuntu Linux since 05.10, [ now 14.04 ] and never got nerdy enough to understand it... I just run it. Have you tried Applications --> System tools --> Ubuntu software center --> Installed --> internet --> highlight --> Remove ? As in example :
  4. Externet

    How to hook up a 2 wire thermostat

    Check the plastic nut connectors have healthy, clean, tight splices inside, at both ends of the heater assembly before replacing thermostat. Diagnose, probe for continuity at the existing thermostat and voltage supply presence. It usually is : ACphase1circuit...
  5. Externet

    How to hook up a 2 wire thermostat

    The original thermostat is meant to interrupt maaany Amperes at the current the baseboard heater element consumes in series to it. Works/rated usually on 230VAC The replacement thermostats shown are wimpy ones meant to signal 24V relays inside an airconditioner/furnace/fan unit to turn on/off...
  6. Externet

    Bone conduction low frequency speaker

    Welcome. Not simple, but... Try an assortment of miniature relays with the coil in series with their C and NC contacts. Perhaps one will be close to 10Hz, or tailoring a resistor in series, or RC components to bring it to desired frequency. It will mechanically buzz nicely.
  7. Externet

    Ultrasonic Water Level Sensor

    There is a weirdish water level sensor used in foggers. I never understood its workings after reading the patent, but may be of use for ..."detect when a water level has dropped below a certain level"... That 'arch' in shrink tubing contains it, stops the fogger when water level drops to it. ...
  8. Externet

    Series Transistor Voltage Regulator

    That is a voltage regulator. Vbe can vary from about 0.6V to about 0.7V. Only 0.1V difference, taken as a fixed value. Your ..."if Vout increases, shouldn't Vbe also increase ?"... Vout is kept steady, regulated to the value. Vout=Vzener-Vbe ----> Vz = Vout + Vbe. In other words, Vout will...
  9. Externet

    Audio tone generator

    To raise bubbles, I would use a table shaker, which is a table with springs as legs, with a motor attached underneath with an eccentric weight on its shaft, speed controlled (dimmer?) Simple to build. Like ----> https://resources.kinnek.com/media/gallery_images/xuukjxkluxbjqsf.jpg To do the...
  10. Externet

    Analog USB... yeeeeeah !

    :( The prostitution of USB. First was upper side band; kidnapped to universal serial bus, then used as a 5V connection, then a charger for whatever, now as audio link, with disregard to the signal carried. What matters now are the wire terminals because are available free to the masses as...
  11. Externet

    Analog USB... yeeeeeah !

    Hi. Opened a tiny speaker amplifier from China and found the audio inputs connected also to a mini USB receptacle traces. The analog USB has born ! ;) [ The brown wires are output to speaker. There is a 3.7V cell under the board. IC is 8002B ]
  12. Externet

    Radio circuit

    Connect several feet of any thin wire to pin 8. Connect pin 14 to +5V DC Connect pin 7 to the negative of your power supply. Now you are transmitting silence at 33.33 MHz and need a 33 MHz radio receiver to test it, as your multimeter cannot. And a LED less. ---->...
  13. Externet

    Loud music from over-the-fence is causing offence...

    If everything fails, your 'fairly powerful amplifier' can play this over the fence while you go away or to the beach : ---->
  14. Externet

    Help with validating that im doing the right thing

    ;) The hillbilly way to do it is inside the oven of a discarded It the printer fits. Powered by 120V instead, with heating elements in series... and a dimmer as temperature control. ;)
  15. Externet

    Faraday cage?

    That discarded microwave oven behind the spider webs can serve well if fits the size. Disemboweling its components will leave a good and lightweight cage.
  16. Externet

    CO detector engine shutoff

    I would stay away from tinkering with the on-board-computer as it will pose a different approach for every brand/model of vehicle. And void warranties and insurances. A relay in series with the ignition coils supply using C and NC contacts can do it. Murphy's law clearly states that the design...
  17. Externet

    CO detector engine shutoff

    Not a good idea. Better rethink it ! Shutting the engine off can impair steering, brakes, air bags and who knows what else; risking the occupants to a much worse condition at higher speeds. Explore loud alarm sound/lights to signal the CO condition, but keep control of the vehicle at all times.
  18. Externet

    Carpenters mistake

    The solder blob is a clumsy mistake from factory with no harm as the traces join below, but better remove it as it may be poorly held and if comes loose from vibration it may contact something doing real harm.
  19. Externet

    1W audio power amplifier driven by electret ?

    Thanks, Bob. Very restricted in dimensions. Speaker should not be over 40mm thick Wondering what are the guts here, to canibalize. Perhaps uses a too much integrated circuitry for multiple functions that would be hard to hack : ---->...
  20. Externet

    1W audio power amplifier driven by electret ?

    Thanks. Am restricted/hancuffed to many things, including only one lithium cell, very tight dimensions... Speaker candidates if there was any way to prove their chinese specifications : ---->...
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