Search results

  1. audioguru2

    Lowpass filter for subwoofer

  2. audioguru2

    about mixer

    The noise is probably Acoustical Feedback Howling and Squealing. This is caused when the microphone can hear the speaker's sound and the amplifier amplifies it so the sound goes around and around. Stop the feedback by turning the speaker and microphone in different directions, by separating...
  3. audioguru2

    Hey all. New member ere. A little help please??

    Hi Staigen, The moderators should quickly get rid of these multiple posts, or merge them together so they make some sense.
  4. audioguru2

    Help: White - Pink Noise Generator

    Hi Tedy, I have used many LM386 power amp ICs, followed the instructions in the datasheet and have never had a problem. The datasheet shows a 0.05uF capacitor in series with a 10 ohm resistor from the output pin to ground to stop a very high frequency oscillation, and advises to keep the gain...
  5. audioguru2

    Speaker to Line Level and Variable Audio - Redux

    Hi Jwest, I understand that the monitor has 8W into 6 ohms speaker outputs which are remote-controllable, and you want to attenuate them and feed the 80W amplifier. It should work with your 11:1 attenuators if the 80W amp has an input sensistivity of about 100mV or 200mV. Otherwise the...
  6. audioguru2

    NiMH Battery Pack Charger

    The voltage of a fully charged Ni-Cad cell depends on the manufacturer, the temperature and the phase of the moon. It is about 1.4V per cell, so a 7.2V Ni-Cad battery will measure about 8.4V when fully charged. Therefore the charging circuit must have a higher voltage to allow a voltage drop...
  7. audioguru2

    0 ohm resistors

    Hi Logan, The "zero ohm" jumpers are the same physical shape as a resistor so therefore are able to be handled and placed on a pcb by automated machines that install resistors on pcbs. Same idea as Ante.
  8. audioguru2

    Diode Limiters

    Hi Muhammad, Welcome to our forum. ;D A diode limiter is usually two small diodes back-to-back to limit both the positive-going and the negative-going part of the waveform. A rectifier is usually larger than a small signal diode to handle high current and is connected to pass DC in a single...
  9. audioguru2

    Help: White - Pink Noise Generator

    The transistor's reverse-biased base-emitter is acting like a 7V zener diode. Have you tried 3.3V or 4.7V zener diodes instead? Have you tried the TL062 noise source circuit with the battery's full 6V to 9V voltage? Have you tried operating the TL062 noise source circuit at 3V and the LM386 amp...
  10. audioguru2

    Hey all. New member ere. Little help please??

    I remember that glow plug engines had a choice of whether the plug was HOT or COLD. I think it was how far the coil was in the combustion chamber, or maybe how well the coil was heatsinked by the cylinder. ;D
  11. audioguru2

    Plants wattering watcher

    Hi Cody, Use a 1N400x rectifier diode for the charger. Since Futurlec doesn't stock 2.5k trimpots, use a TRIM2K in series with a 510 ohm resistor to ground. Hi Staigen, My plants like the very small AC current from my circuits. Maybe the current kills the bad things in the soil. Surely the...
  12. audioguru2

    Plants wattering watcher

    Since your solar cells can output a max current of only 60mA and your Ni-Cads need 55mA for 14 hours, the Ni-Cads will never be fully charged and the charger is only 2 solar cells in series and in series with a diode. Any diode will be fine. I don't know if a single circuit can have multiple...
  13. audioguru2

    0 ohm resistors

    Yes.
  14. audioguru2

    Plants wattering watcher

    Hi Cody, I guess that my circuit will work, I didn't try it. You can disconnect pin 9 of the LM3915 for a DOT current-saving mode.
  15. audioguru2

    Plants wattering watcher

    Hi Cody, In the Plants Watering Watcher-2 circuit, the IC's pin 8 is oscillating at about 2 Hz, and pin 11 is Pulse-Width-Modulated at about 3kHz. I have made pin 11 feed an inverter which is integrated with an RC pair into a DC voltage which represents the dryness between the probes. Then I...
  16. audioguru2

    need n finding the datasheet

    Hi Rash, Welcome to our forum. ;D A couple of companies still might make the 8038 function generator. Here is the datasheet of one of them: http://www.datasheetarchive.com/datasheet.php?article=1726703
  17. audioguru2

    Plants wattering watcher

    Hi Cody, The Plants Watering Watcher-2 project can be modified easily to produce a DC output voltage for driving an LM3915 bar-graph LED display. Your 2.4V battery is a problem for the LM3915 since it needs a min of about 3.0V. If many LEDs are lighted then they will quickly discharge the battery.
  18. audioguru2

    Question on the Plants Watering Watcher circuit

    Hi Cody, My tap-water has enough salts and minerals in it that it causes my Plants Watering Watcher-2  circuits to measure the same as a 47 ohm resistor between the probes. The water isn't acidic, it has dissolved conductive salts and minerals in it. "Pure" water doesn't conduct electricity and...
  19. audioguru2

    NiMH Battery Pack Charger

    Hi CPW, Energizer does not recommend a quick charge quicker than 1 hour so that the battery cells will last longer without experiencing overcharge. They say that the voltage peak for Ni-MH cells is much less than for Ni-Cads and a circuit can easily miss it, also it occurs too late when...
  20. audioguru2

    500W 12v to 220v Inverter

    The 0.1 ohm/10W resistors are needed if the load is 500W. The circuit will draw about 600W from the 12V battery which is 50A. Each output transistor and its emitter resistor will share the 50A so each will have 50/4= 12.5A for half the total time, so your 0.2 ohm/3W emitter resistors will each...
Top