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  1. audioguru2

    ISS108 diode information reqest

    Did you sim it with a 74HC14 and not a CD74C14? The 74HC14 has about 10 times the output current of the ordinary Cmos CD74C14.
  2. audioguru2

    555 monostable Operation problem

    Hi Shaiq, If the trigger goes to ground for a time period that is too long then add a 10k resistor from pin 2 to the positive supply and a coupling capacitor from the trigger source. Then it makes a short negative pulse no matter how long the trigger source is grounded.
  3. audioguru2

    Audio/Sound Amplier

    The LM386 amp works with a supply voltage from 5V to 12V. 9V is fine and the max power will drop as the battery voltage drops as it is used. The ground connections are all connected together. I have it detailed here:
  4. audioguru2

    555 monostable Operation problem

    Hi Shaiq, The datasheet tells how to use a 555. If the trigger pin is held low then the timing cycle will never end.
  5. audioguru2

    ISS108 diode information reqest

    1mA through 1k is 1V, not 30V! Sure it will provide about 2.6mA at 30V.
  6. audioguru2

    Audio/Sound Amplier

    An LM386 is an IC that is inexpensive and works very well with only a few extra parts. If you don't want an IC then a simple amp will have only 3 transistors, doesn't work as well as an LM386 IC, has more parts and costs more.
  7. audioguru2

    ISS108 diode information reqest

    Hi Steven, Each 74HC14 inverter has an output current of about 10mA with a 1V drop. So 4 in parallel make 40mA for half the total time and the 30V output will be about 2.6mA. The 5V average current will be about 17mA when the 30V has a 2.6mA load.
  8. audioguru2

    Transformer Power Rating

    Why make a complicated power meter? The power changes in less than a milli-second so a 7-segment display will be a blur. You hear loudness, not power. Just make an LM3915 LED bar-graph sound level meter or voltmeter. Have a peak-detect circuit to hold readings for about 50milli-seconds so they...
  9. audioguru2

    Stereo to Mono

  10. audioguru2

    Stereo to Mono

    Shorting outputs together causes a high current to flow when the outputs are different. Resistors reduce current flow and allow the signals to still be added together.
  11. audioguru2

    Stereo to Mono

    It depends what it is. If it is a stereo power amplifier then you can't just short the two outputs together, damage will occur. If the stereo outputs are from opamps then you also can't just short them together. You need an adder circuit to add the left channel and the right channel to get mono...
  12. audioguru2

    Transformer Power Rating

  13. audioguru2

    Sine wave Inverter Project

    Sure, you can use a couple of RC lowpass filters or an LC tuned circuit. Then the load must be a high impedance so no power can be drawn.
  14. audioguru2

    Sine wave Inverter Project

    Then you are making a class-D car amplifier that doesn't have as much power as the ones you can buy.
  15. audioguru2

    email notification reply to topic problem

    I deleted it because I thought the power supply had a positive and a negative outputs. But it doesn't, it just has a very high voltage output.
  16. audioguru2

    Car Alarm

    Your circuit has the collector-base diode of the PNP transistor forward biased and shorting the battery. Transistors always have the collector-base connected with reverse bias voltage. Your NPN transistor is connected correctly as an emitter-follower, however the transistor might fail because a...
  17. audioguru2

    High Quality electronic sites

    I used to be able to see all Silicon Chip's projects in Google for free. Not anymore.
  18. audioguru2

    Electronic parasite zappers

    I'm glad that a little 9V oscillator is all it takes to stop a kangaroo from biting you! ;D
  19. audioguru2

    Sine wave Inverter Project

    The archive notes say 102W into 8 ohms or 180W into 4 ohms. It quickly got very warm with 180W output and so the mosfets need better heatsinking. Efficiency was about 86%. Note that its power supply is positive and negative 50VDC. About eight 12V car batteries in series would power it.
  20. audioguru2

    email notification reply to topic problem

    Sorry, it was my fault. :'( I made a reply to Steven's topic then quickly deleted it. Then Steven got an e-mail about my reply which couldn't find it because it was deleted. My PM's work fine because I get some every day.
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