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Type: Posts; User: BradtheRad

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  1. Closed: Re: Lenovo laptop problem during installing LINUX OS

    I once installed Linux on my Compaq laptop (to a re-formatted hd). Things worked to the point where I saw the desktop open and appeared normal. However it froze when I tried to open any application....
  2. Closed: Re: Capacitance divider of Colpitts Oscillator

    A capacitor by itself creates current lead (90 degrees). By adding a second series capacitor, and tapping between them, these effects result:

    * modifies the amount of phase change (possibly...
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    Closed: Re: Simulation Buck Converter

    For a tutorial, here is a simulation containing the chief components of a buck converter. It is animated and user-interactive (you press the momentary switch to operate the converter).

    Electron...
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    Closed: Re: Soldering on Battery Terminals

    Is the question about small AA or C or D cells? These are available with solder tabs (a few dollars each).

    I confess I solder wires directly to rechargeable C and AA cells. It keeps my electric...
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    Closed: Re: Technika lcd22-208 tv

    Perhaps after a few seconds the setting is applied even if you don't press OK?

    There are store-bought 'universal' remote controls, for use with a large variety of appliances. The instructions give...
  6. Closed: Re: Tuning of varicap diode in a magnetic loop antenna based on modulating signal

    Your concept sounds similar to Automatic Frequency Control (or Automatic Fine Tuning), found in many FM receivers going back about fifty years.

    It was useful as long as it stayed perfectly...
  7. Closed: Re: Does it exist an AC to AC converter in small package for converting 220v to 110v?

    I've seen advice telling to derate (reduce) power to an inductive load rated for 60 Hz, when you run it at 50 Hz. The reason is because an inductor admits greater current at the slower frequency. The...
  8. Closed: Re: Best books for Current mirrors and differential amplifiers using MOSFFET

    A differential amplifier is commonly made from a long-tail pair. I needed to experiment with simulations, for hours at a time, to learn its behavior.

    The left-hand transistor plays give-and-take...
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    Closed: Re: Booster converter Circuit

    A plain red led should light when you apply 1.8v. (There are other colors but they require higher voltage.) It should conduct several mA. Do not allow more than 20 mA. Install a safety resistor if...
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    Closed: Re: Elementary questions

    The Elementary section becomes an easy choice for many members, rather than to take effort to look over the sections and decide which is the proper choice to post their question (even if the topic...
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    Closed: Re: Booster converter Circuit

    Your test results appear to prove the concept. The latest plan was to supply 9V power to the IC, but bring 'tree power' into the boost stage, correct?
    Now if you truly took 1.1V @116mA tree power,...
  12. Closed: Re: measuring slow oscillations with magnetic methods

    For a coil, the article recommends a telephone pickup coil, or a 9V relay. Small is sufficient. The magnet has to jiggle easily, so it should be lightweight. Likewise it only requires a small coil...
  13. Closed: Re: measuring slow oscillations with magnetic methods

    A Forrest Mims book has an earth-movement sensor project exactly like you describe ('Science Projects' Mini-Notebook, pg 40-41). Suspend the magnet on a string. Position a coil of wire just below the...
  14. Closed: Re: Matching network for low frequency upto 500 Hz

    A simple passive filter (example, resistor & capacitor) needs a certain minimum level of current to drive it. If it loads the incoming signal then it won't yield your desired frequency response. In...
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    Closed: Re: Booster converter Circuit

    By trying various tests you may find an arrangement which creates greater voltage differential, and/or greater current.
    Examples:

    * One probe in the root, other probe several feet high.
    *...
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    Closed: Re: LTspice model for COB LED

    The graph shows the LC019D conducting 1A at 37V.
    Starting out with a simulation, I changed the led to that spec, but it makes the curve too steep (because the led equation is exponential). However...
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    Closed: Re: Booster converter Circuit

    It's too much for you to expect 100mA from your setup. It's not that different from the store-bought LCD clock powered by a battery made from copper and zinc strips poked into a lemon... or two...
  18. Closed: Re: Coded Ultrasound Pulse obstacle finding

    Evidently a lookup table (reference) is stored. The algorithm compares the echo times, together with the lookup table. The result is distance of an obstacle, perhaps height and direction.

    That's...
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    Closed: Re: Variable current sense, will this work?

    You are correct. Temperature change causes readings to drift. I saw this in my own tests as I squeezed the transistor between my fingers. The reading changed. When I let go, the reading returned to...
  20. Closed: Re: May ordinary USB flash port be different???

    Yes, that sounds like an odd arrangement on the circuit board if the connector has to change the order of the wires.

    To make progress in fixing the problem, you need to know the correct sequence...
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    Closed: Re: Variable current sense, will this work?

    You can detect and amplify sense voltage via common-base operation of a transistor. My simulation has 2 milliOhm sense resistance. Even that low amount is subject to several Watts when carrying 50A....
  22. Closed: Re: May ordinary USB flash port be different???

    Did the port become damaged by a device which extracts or forces a lot of current through it?

    There is a sequence called enumeration, which starts by allowing a device to draw 130 mA (but no...
  23. Closed: Re: measuring slow oscillations with magnetic methods

    Shine a narrow beam of light onto the moving surface, at an angle so it reflects and creates a dot where you place a photodetector. Arrange your setup so that you get maximum motion of the dot....
  24. Closed: Re: May ordinary USB flash port be different???

    So did this fix the port?

    Did you match each wire color correctly? The four wires need to be arranged in the correct order.

    Since you caused an 'overload' message, it suggests you got wires...
  25. Closed: Re: Adding a light parallel to existing loudspeaker circuit

    There is a slim chance it's no harm if you steal some signal from the speaker, and run it through a converter to light up led's.

    154080

    This idea can only work if the output from the...
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