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  1. K

    again, microphone input high school project

    I'll be honest, this is an AC triangle applied to a diode and capacitor and the voltage out is 1.5 VDC and the input is 2.5 volts peak. This is more DC than I expected. You have to realize that when the voltage falls, it also falls at the capacitor. It's the DC supply from the capacitor that...
  2. K

    again, microphone input high school project

    Hello, Audioguru I managed to experiement with the triangle wave. The results where untinteresting, the peak to peak was low and so was the DC. You see every cycle charges the capacitor at the point where there is zero rate of change. Otherwise you simply have a diode capacitor filter. And as...
  3. K

    again, microphone input high school project

    What I am saying is that you will have trickles of DC charge at all levels with a microphone signal. You can't expect the peaks to give you much DC. Conversely, when you charge a capacitor with mains you get a nice DC charging. It is also imperative that it completely charges to the voltage in...
  4. K

    again, microphone input high school project

    Audioguru, you know you can't get DC from trying to filter a triangle wave.
  5. K

    again, microphone input high school project

    There is one problem. You may not be able to get a DC from the signal. A filter capacitor will only capture the DC level if it is there. It is likely that you will end up with a very small ripple but no DC. And as far as I can tell you would be hardpressed to even get that DC from the signal...
  6. K

    True RMS

    My meter does not measure true RMS. Consequentally I measure a clock signal of 5 volts and get the same 2.5 average and 2.5 RMS. By my RMS calculation, I should get 3.5 RMS.
  7. K

    transformer questions

    Somewhere I read that the rms value is the DC voltage that produces the same amount of power. To begin, the rms affects the equation of the signal inherently. The average does not. For rms, the equation is squared and the area found. Divide that by the length and you get the average of the...
  8. K

    switching circuit

    I would suspect the reason for the microcontroller in the application of a battery charger would be to control the voltage applied to the battery. Neglecting the current, there is a voltage that must be applied to the battery depending on the energy already stored. The predestined goal of the...
  9. K

    What oscillator/clock should I use

    There are good oscillators and better ones. The best oscillators are the ones that have the inventers names attached to them. In the case of clock oscillators, there is always a capacitor that is at the heart of the oscillator. Then you are left with a logic circuit which works equally well from...
  10. K

    Coupling capacitors!

    A capacitor draws current from both sides when there is a rate of change to the applied voltage. Since the current that is being drawn through a resistor creates voltage, you have what appears to be a passing of the voltage.
  11. K

    wireless FM Transmitter

    Your talking a receiver transmitter for reproduction of an audio signal. It can be done but is bound to be inefficient should you choose to do it yourself. I don't even know of anything I could recommend. Although, sometimes things of this nature can work to a degree that you are satisfied with...
  12. K

    DVM??

    There is very little difference between the dual slope and the single slope. Both methods are good and even the single slope requires two ramps. I chose a project with the dual slope because I could set the reference voltage at ground potential. It is not often hard to conceptualize the problems...
  13. K

    help oscillate

    An AM modulator can be made by simply running two signals at each other across the PN junction of a transistor. The amplitude simply changes the higher frequency carriers amplitde at a rate. How is this different from addition?In addition, you have the composite which will look sort of like the...
  14. K

    newbie confused with voltage dividers

    I think the problem you are describing has to do with the fact that you cannot get a good voltage source from a divider. When the load current changes, the voltage will change. The amount of change is determined by the resistances you use to get the voltage. From the viewpoint of the load, the...
  15. K

    DVM??

    A digital voltmeter has to convert the voltage of the signal to a binary represention for digital readout. This requires an A/D. So a dual ramp A/D uses one ramp that takes the voltage higher and another ramp which lowers the voltage. This is how you create a time difference, by taking the...
  16. K

    Inductance Calculation

    Just one second Ante. I believe DC describes current that flows in one direction. So can see that a transformer can in fact work with DC.
  17. K

    Inductance Calculation

    The primary inductance is not all that important but you can calculate it. I can't remember what the formula is, but it has to do with the transformers specifications. Incidentally, the transformer can be operated in the specified frequency range which has to do with it's inductance.
  18. K

    HV power supply

    I don't think you will get the current you desire. Since the current will depend on the capacitors you use, which will be small, you will not get much of it. The peak of the input cycle delivers power to the load because it is where the capacitors will charge from with the diodes in there. The...
  19. K

    Dec to bcd conv

    Why not use an encoder and just use 0 through 9 inputs.
  20. K

    COLOR DETECTOR

    How I think it works. Use three color sensistve light receivers. The intensity modulates with the three oscillators connected to the three light receivers. You can combine the three signals on one line. Then the waveform produced carries all three basic colors and their intensity.
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