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  1. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    You showed Ante's analog sine-wave inverter with an efficiency of only about 60%. EDIT: The output Mosfets operate in class-A, so the inverter's efficiency might be as low as 33%.
  2. audioguru2

    led lamp

    Hi Iceman, I couldn't find white or blue LEDs with a voltage less than about 3.3V so you are going to need a voltage stepup circuit to power them with only two AA battery cells. The LMC7660IN is a "charge-pump" IC that makes a negative voltage. It has an output resistance of about 90 ohms and...
  3. audioguru2

    led lamp

    LEDs blow if you allow too much current through them, or connect the LED or the battery backwards. The current is limited by wiring a resistor in series with each LED. The resistor is determined by Ohm's Law, the battery voltage, the LED's voltage and the current needed that is probably 20mA...
  4. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    MP, Is your proposed digital sine wave amplifier or inverter with "varying heights of its steps" on the web? What would be its efficiency as an amplifier or inverter? I showed a square-wave inverter and a modified sine-wave inverter with large digital steps with a pause in between. Their...
  5. audioguru2

    Begginner help

    Did you see this boat?: http://media.putfile.com/HydroFoam
  6. audioguru2

    Begginner help

    Hee, hee.  ;D ;D A 10k resistor won't move nor fly by itself, but smoke from it will if you put about 1kV across it. ;D ;D
  7. audioguru2

    Begginner help

    Hi. I think the 10k resistor provides all the traction when it turns left. I dunno what starts it moving nor what makes it go straight or turn right. ;D Can the mouse do this?: http://media.hugi.is/hahradi/fyndnar/skycutter40.wmv
  8. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    Actually, since the digital PWM waves of a class-D amplifier all have the same height, and are also constantly clocked, there is far less heating than in your proposed "vaying heights" plan. Most fairly high power class-D amplifiers are surface-mount, and don't even need a heatsink. Class-D amps...
  9. audioguru2

    Electronic Stethoscope

    Hi Duke, Welcome to our forum. ;D You must be talking about my Electronic Stethoscope 2 project, because the original project didn't have most of these important parts. 1) The electret microphone has a field-effect transistor impedance converter inside. R1 powers it and provides a load for it...
  10. audioguru2

    LED driving

    Many video cameras are sensitive to IR. If you modulate an IR diode with an oscillator, it will interfere with the frame rate. Just power the IR led with direct current. You might need a bunch of them for enough IR brightness.
  11. audioguru2

    Inverter Circuit 12V DC to 230VAC Sine Wave

    The linear sine-wave inverter/heater is nice because it regulates the output voltage. The digital then smoothed sine-wave circuit is how class-D audio amplifiers work. ;D
  12. audioguru2

    I need to balance an amp HELP!!

    I'm a turbo-charged old geezer. ;D
  13. audioguru2

    Multiple Switching Help!

    Yeah, It's best done with a micro. Using flip-flop IC's would need an awful lot of gates and stuff to reset the others when one is selected. The method I thought about would actually also reset the one that is selected! :-[
  14. audioguru2

    I need to balance an amp HELP!!

    Hi Firediv, Welcome to our forum. ;D A simple 1V 1kHz sine wave generator is in our projects section: http://www.electronics-lab.com/projects/oscillators_timers/002/index.html
  15. audioguru2

    FM Radio

    Hi Mr. Popo, They are completely different. The BB329 has a wide tuning capacitance range of 12, the others only a little more than 2. I copied and pasted their datasheets from www.datasheetarchive.com .
  16. audioguru2

    LED driving

    Yes, the brightness of an LED is determined by its duty-cycle. If it is switched on and off at a frequency high enough that it doesn't appear to flicker, if it is on only half the time then its current must be doubled for it to appear as bright as one that has a steady current...
  17. audioguru2

    led lamp

    Hi Iceman, The blue and white LEDs that I have require more voltage than a pair of AA cells, and much more voltage than when the 3V from the cells reduces to only 2V over their life. They need around 3.3V. Are you using a voltage stepup converter circuit? In my "6V Ultra-bright Chaser" project...
  18. audioguru2

    lots of new circuits

    Sorry Dazza, The satellite pic isn't clear enough from your part of earth fo us to see you. My son discovered a pic of my new car parked in my daughter's driveway, but a pic of my house shows my old car. Places near me are very clear on the Earth.Google satellite shots..
  19. audioguru2

    Linear Voltage Regulator Design

    You are darn right it's oscillating. It has way too much open-loop gain. An LM317 voltage regulator IC has a very tight layout and frequency compensation capacitors inside, and nowhere near as much open-loop gain. 
  20. audioguru2

    Laser question

    A hologram is the result of a laser beam and its reflected interference pattern of an object and shows up in mid air. A visible laser beam is light, so can be detected with a light detector: photodiode, phototransistor or light-dependent-resistor.
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