Search results

  1. audioguru2

    "Cannot Connect", again and again

    Mixos, I got the same Fatal Error twice: 1) About 15 minutes ago, when I tried to log-in. 2) About 10 minutes ago, when I tried to reply.
  2. audioguru2

    "Power?" Inverter

    In the interests of safety (exploding capacitors) and quality (previously posted), this dangerous and defective project should be removed from our site. Let us not have anyone injured. We already have a good re-engineered inverter (Low-cost, 500W).
  3. audioguru2

    touch switch

    It is no wonder that neither me nor my search could find it, "Tough Switch". What's tough about it? Where's the schematic?
  4. audioguru2

    "Cannot Connect", again and again

    Maybe it is programmed to give a different advertisement for each page, but sometimes the ad is the same on your next page which causes a conflict, "cannot redeclare".
  5. audioguru2

    "Cannot Connect", again and again

    That's the same occasional Fatal Error message that I get, ever since the Apache software upgrade.
  6. audioguru2

    Electronic Stethoscope

    Cdak, I am glad that you got your LM387 (obsolete) pre-amp working so well with an external 7th-order HPF used to reduce 50Hz hum pickup. Have you considered a simple notch-filter? Are you still using the 9th order LPF that you mentioned earlier? What frequency does the LPF cut-off at? Do you...
  7. audioguru2

    Analog/Digital GND

    Siddharth, Actually, the opposite is true. When a digital circuit changes its output state from a "0" to a "1" and back, a current pulse is created in the ground wiring which causes voltage spikes (digital hash) along it. The digital circuits are not affected by reasonable (10% to 30% of the...
  8. audioguru2

    "Cannot Connect", again and again

    The site's clock and my time-zone shift worked fine before the Apache software upgrade. Now it is exactly 10 hours behind. Am I the only one affected?
  9. audioguru2

    Why are PCB's green on the trace side

    FlipFlop, In addition to stopping corrosion of traces, the solder-mask saves manufacturers the cost of extra solder and its weight in the product.
  10. audioguru2

    need help for a project

    Cmer, What kind of LEDs and why must they be in series? If they are common red LEDs, and they have a voltage of 1.8V each, then you must use a DC to DC converter to step-up the 5V so that they will have 5.4V across them plus more voltage for a transistor or IC current-limited switch. Other...
  11. audioguru2

    "Cannot Connect", again and again

    Now that the server has its Apache update, I frequently get new errors from the site or server: "Fatal Error. Cannot redeclare phpadment....." and ".....advertisement....." so I must go back in my browser, then forward and it is OK. The clock is showing the wrong time.
  12. audioguru2

    [email protected]

    Jacob, Do you want to measure the time that the object stays on the platform, after landing, before it bounces or falls off?
  13. audioguru2

    70 volt regulator

    Kevin, I think that you "roasted" the little zener if you put 1.5A through it. Next time use a current-limiting resistor in series.
  14. audioguru2

    Project Help

    MP, Thanks. I didn't have Paint installed, but I do now. Now I can scratch-out simple schematics quicker than Eagle. I just now converted a 4MB BMP schematic to a 240KB JPG and they look the same. I'm saying goodbye to all my BMPs.
  15. audioguru2

    "Cannot Connect", again and again

    Ante, I am on cable and are running at 350KB/s to 1MB/s and on most other sites a screen snaps on display only a moment after I click. Mixos, Thanks for trying. It must be difficult for you.
  16. audioguru2

    Power supply for AMP in CAR

    MP, Back to the "darlington transistors" argument. Power darlingtons also use base-emitter resistors too: http://www.fairchildsemi.com/ds/MJ/MJE803.pdf
  17. audioguru2

    70 volt regulator

    Sorry for my repeat of GPG's formula. I didn't see page 2 when I replied.
  18. audioguru2

    70 volt regulator

    That circuit provides a regulated output voltage by this calculation: Zener voltage plus 0.65V (base-emitter) multiplied by (R1 divided by R2) plus 1. The zener is the voltage reference that the divided output voltage is compared with. Since a zener is low impedance, changes in current through...
  19. audioguru2

    OPAMP questions

    Kevin, What opamp circuit has its input capacitor connected to ground? Input capacitors usually couple in series an AC signal source to the opamp input and bias resistor for noninverting, or opamp input resistor for inverting circuits. The low-frequency rolloff of an input coupling capacitor is...
  20. audioguru2

    How do I make a dc circuit auto-off after 60 minutes

    Kevin, That's correct, when the capacitor voltage reaches about 11.3V, then the timing period is over and the transistor turns off. The switch resets the circuit by discharging the capacitor (and turning-on the transistor). The transistor stays-on during the timing period when base current flows...
Top