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  1. audioguru2

    Linear Voltage Regulator Design

    Hi Alun, Good point! ;D The MC34071 is rated for a 44V supply so the extra input voltage is fine.
  2. audioguru2

    Internet Problems

    Hi Ante, Not all of New Orleans is destroyed. A TV crew interviewed people who refuse to be evacuated because their part of town is fine. No flooding and no damage. Stores are open there. A school was closed because of the evacuation and the only damage to it is a broken window from a kid's ball...
  3. audioguru2

    Antenna and TV standard

    There is a local company making TV antennas for farmers and other people living away from the cable-TV in the city. It is a very expensive antenna made from the cardboard tube that carpet is shipped on, with a spiral of aluminum foil on its surface. It is sold and installed with a rotor and...
  4. audioguru2

    high voltage photo flash capacitor charger

    Hi Steven, You are absolutely correct! ;D Your uf4007 rectifier diode is fast. It is much faster than a 1N4007. You made a good choice. ;D A uf4007 has a max reverse recovery time of 75ns. A little 1N4148 diode 's time is only 4ns, but its voltage and current ratings are too low for your...
  5. audioguru2

    NiCd - NiMH Charger

    Hi Dito, An LM317 has a voltage drop of only 1.25V when used as a constant current source. A 7805 would have a 5V voltage drop if used as a constant current source so its current-programming resistor must be changed and the input voltage must be higher. With a higher input voltage then a 7805...
  6. audioguru2

    high voltage photo flash capacitor charger

    Hi Steven, A 1N4007 rectifier diode isn't high speed, it is a slow mains rectifier diode rated at 1kV. A high speed rectifier diode would charge the capacitor quicker and the driver transistor would operate cooler. Your high voltage indicator circuit loads down the capacitor voltage because...
  7. audioguru2

    capacitor?????

    Maybe this cap is made by Sprague-Barre (SB) Electronics:
  8. audioguru2

    capacitor?????

    Eight of these 200V caps in series makes 1600V. Maybe only (!) 1500V is used to power an inverter at the primary of a stepup transformer producing 120kV for a CO2 laser or some other kind of beam maker. These caps carry a very high current. Look at the size of them and the size of the metal beam...
  9. audioguru2

    Internet Problems

    Hi Staigen, Thanks for the tips. In the morning I'll try surfing here from my son's PC upstairs, then complain to my ISP. ;D
  10. audioguru2

    Internet Problems

    I had to reload only 3 times to get here this time. None of the Smiley buttons appear, nor the Insert buttons above them. Completely blank. My browser appears that everything is loaded and it is finished, but doesn't say Done. Maybe the server has a defective internet input path that is used...
  11. audioguru2

    Internet Problems

    Hi Staigen, This site has been working fine for me for about 1 hour. If the problem is in something along its internet path, how can I change the path to avoid the problem?
  12. audioguru2

    capacitor?????

    Yellow epoxy.
  13. audioguru2

    Linear Voltage Regulator Design

    Hi Alun, Now that you have a negative supply, you can use a TL071 or TL081 opamp for U3 because their inputs operate up to the positive supply. Their supply voltage is only 36V max so will probably be exceeded when the load is low. TI probably has an opamp with inputs that operate at the...
  14. audioguru2

    Internet Problems

    Hi Staigen, This site is fine for me at this moment. I have Windows XP Home. It doesn't have DOS but maybe can simulate it somehow. I don't use ICQ but maybe I will. I use MSN Messenger for communicating with my kids. ;D
  15. audioguru2

    Stripboard + Acetone

    "Gas line antifreeze" for cars is pure, dry Isopropyl Alcohol and "absobs" water in the gas tank and gas lines caused by condensation. Isopropyl Alcohol that you can purchase might be watered down, or contain water it has absobed from humidity. I don't think you want to use a cleaner with water...
  16. audioguru2

    capacitor?????

    I think it is paper and foil. The paper is inpregnated in wax or oil. See, I am a poet! ;D
  17. audioguru2

    Internet Problems

    How?
  18. audioguru2

    Internet Problems

    Hi Staigen, Nope, I have big problems getting pages to complete loading, and when it is bad the pages load very slowly. I reloaded about 12 times to get this page so I could read text on it, and at the bottom of my IE6 browser right now it say, "11 items remaining, Downloading picture http://"...
  19. audioguru2

    MIC coupling capacitor

    Hi Walid, The datasheets for your tiny BC817 transistor don't have its Hie input impedance. A 2N3904 is a similar transistor and its datasheet shows it having about a 2k ohm input impedance in your circuit. I tested my electret mic to have an output impedance of about 3.3k including its 10k...
  20. audioguru2

    Linear Voltage Regulator Design

    The MC34071 opamp (or MC34072 dual or MC34074 quad) that I recommend has a max supply voltage of 44V. Its inputs can work fine down to ground. Its output can swing almost to ground. Just connect its supply pins to Vin and ground. ;D Hi Ante, The MAX420 is a chopper stabilized opamp that is very...
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