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  1. audioguru2

    Why 50 50 50 maximum power

    Hi Kevin, The output impedance of an audio amplifier has nothing to do with its bias. An amplifier can have no bias (class-B) and still have a low output impedance. The output impedance is totally dependent on the amplifier's negative feedback. If an amplifier has an open-loop output impedance...
  2. audioguru2

    Need VALUE for resistor..

    Hi Rhonn, The 12V output won't stay at 12V with either a 110V mains or a 220V mains unless it has a 5W zener diode across it. Drop the voltage with a 1K resistor. With a 110VAC mains, the 12V load's current is 100mA and the zener's current is 42mA. With a 220VAC mains, the load's current is...
  3. audioguru2

    eq. or parametric analizer

    Hi Ante, Thanks for the excellent article. "Instant death", "180dB". Insane, alright! :o
  4. audioguru2

    3V LED Chaser project

    Hi Guys, Oh, oh. I found a problem with the "6V" version of my ultra-bright LED chaser circuit: It eats batteries! My ultra-bright blue one wasn't as bright anymore because its battery voltage dropped to 5V (it started at 6.2V). I've had it for a month and turn-down its brightness and speed...
  5. audioguru2

    heavy duty batteries

    Hi Ante, Hopefully you would hear it coming. I attended a model airplane show and its highlight was a very expensive model jet plane with a real miniature jet turbine. It looked, sounded and even smelled like a full size jet plane. It flew its max speed of about 500km/hr and you couldn't hear...
  6. audioguru2

    eq. or parametric analizer

    Hi Ante, I was looking and looking to find what is the absolute maximum achievable sound pressure in air at sea-level and at 25 degrees C. That is when the air compresses to double atmospheric pressure for half-cycle and total vacuum on the other. I could't find it in the maze of kpascals...
  7. audioguru2

    heavy duty batteries

    I agree, Ante, A simple circuit can detect a low receiver battery voltage and cutoff power to the main motors. I thought all RC systems had such an arrangement. What would have happened if someone was in its path and didn't see it coming? OUCH! An RC airplane might be worse than a car if...
  8. audioguru2

    Dont understand Schematic

    Hi Kevin, "You don't understand the schematic". ??? It doesn't have an oscillator output. The entire circuit is simply a touch-activated momentary switch. It is unique in that you don't have to touch two touch-pads at the same time to conductively activate it like most touch-switch circuits...
  9. audioguru2

    eq. or parametric analizer

    My statements are true and accurate, not offensive and certainly not ridicule. Do you know how loud a sound pressure level of 150dB is?
  10. audioguru2

    Site's Clock

    I very politely asked that this trivial task be looked at with no rush, in this forum called, "Feedback/Comment". My asking was for feedback to the administration of this site and our discussion about it is the comment.
  11. audioguru2

    LM317 circuit doesn't supply enough current (only 20mA)???

    MP, If the wall-wart is capable of supplying only 20mA (plus some more to operate the regulator) at 12V, then its voltage will drop if you try to get more current won't it? You don't need to test the wall-wart separately with its own current-test resistor, the regulator and its load are its...
  12. audioguru2

    Site's Clock

    Hi Ante, Electronics-Lab started with a server in Greece, but Mixos changed it to a California server awhile ago, maybe 'cause it cost less. Mixos and most of his sponsors are still in Greece. Unfortunately, the server bases its time on local time instead of the standard GMT. I don't know why it...
  13. audioguru2

    Site's Clock

    Hi Ante, Sorry, but your clock must be wrong. This site's server is now in California, so bases its time on Pacific Standard Time (or whatever those Californians call it), not GMT like other sites do. Your clock is probably 10 hours ahead of the server's time. I am in the Eastern Standard Time...
  14. audioguru2

    how to do a ring detector???

    Hi Lethenl, If I wanted to make a telephone ring detector I would simply use a ring detector IC. It will even make a "ringing" sound in a speaker. If I wanted to do it the hard way and use many discrete parts, I would first study the theory about how a telephone and a telephone system works...
  15. audioguru2

    big ear, fm transmitter.

    Beer (Carnagie's Porter brand?) makes a very good pop filter, just ask Ante. A pillow filters a burp pretty well. ;D Steven, you got a bad pot. :'(
  16. audioguru2

    Site's Clock

    Ha! See? This site says I posted it 19 minutes from now.
  17. audioguru2

    Site's Clock

    Fast? You ain't seen nutthin yet! Let's check the clock. For my exact time, I am posting this at: 21:26
  18. audioguru2

    Dont understand Schematic

    That's correct with the 2N2222 connection. The "sink" output by itself may be able to turn-on the PC, if it needs a logic low and has its own pullup resistor. If you use an opto, it will also need a current-limiting resistor (for its LED), but a value probably lower than 1K since it doesn't...
  19. audioguru2

    Interpreting Datasheets

    Hi Shekhar, The spec's for most transistors vary up to 8 times from guaranteed minimum to maximum. You can buy them with the current gain selected with a narrower range if you pay more. You can't even bias the base of a transistor at 0.7V with a voltage divider, because one transistor will...
  20. audioguru2

    If you are looking for good FM Tx, Look at this Link

    No penguins in the North? No polar bears in the South? They don't meet in the middle? ??? Gee! Thanks for the trivia.
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