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  1. audioguru2

    Digital radar speedometer

    The 2nd oscillator gates the clock pulses to the counter from the photodiode.
  2. audioguru2

    Digital radar speedometer

    Yes, the laser beam is modulated in our project. The oscillator is a two-inverter Cmos type without any accurate parts, and without any calibration adjustment. The oscillator appears to operate at a high RF frequency and a similar but lower frequency oscillator is used for gating the...
  3. audioguru2

    lesr from iraq i need help with 500w inverter

    Did you make the 500W inverter in our Projects section? The resistance of a 230VAC/500W load is only 105 ohms. The reactance of a 2.2uF capacitor at 50Hz is 1455 ohms. So the capacitor barely rounds the edges of the the square-wave at full load. If the load draws a low current then the circuit...
  4. audioguru2

    100W Amplifier Help

    There is no such thing as "p-p power". You have calculated 204.2W as the "peak power" which is simply a number that is double the real continuous power. Will the amp drive a 6 ohm speaker at high levels reliably? The current and heating is 33% higher than with an 8 ohm speaker.
  5. audioguru2

    Cascode Amplifier

    It isn't a cascode amplifier. Its parts values must be designed by using the circuit's requirements: Voltage gain, frequency response, input and output impedances, min and max output levels, power supply current,  distortion, etc.
  6. audioguru2

    [help] Getting pure DC current

    By the way, you should also download the datasheet for the 7805 regulator. Its minimum input voltage is about 7V to 8V. Its output voltage will be about 4V and is not regulated with a 5.8V input. Also it needs a capacitor on its input and a capacitor on its output is recommended in the datasheet.
  7. audioguru2

    [help] Getting pure DC current

    Of course they get hot: your power supply connections are backwards! You should download the datasheets of the microcontroller and the display. I get datasheets from www.datasheetarchive.com . Why post your schematic as a 1.33MB huge bitmap on another site, when you can change its file type to...
  8. audioguru2

    Digital radar speedometer

    It is a Cmos Schmitt-trigger oscillator whose frequency changes with supply voltage changes and temperature changes. See my attachment. The laser doesn't shine on the photodiode. Maybe the laser is modulated with a tone and the doppler shift changes the tone's frequency, then the two tones are...
  9. audioguru2

    HELP - resistors and dip-switch

    Hi Allvol, "My" 555 circuit is the classic "triangle wave into a comparator with the other comparator's input connected to a variable DC voltage" PWM circuit that usually uses a opamp integrator and a Schmitt trigger oscillator to make the triangle wave. The 555's timing capacitor is charged and...
  10. audioguru2

    Digital radar speedometer

    They are cheap and crude. A free-running oscillator is used in the display circuit and its frequency is adjusted for calibration. A real speedometer uses a very accurate quartz cryatal oscillator.
  11. audioguru2

    [help] Getting pure DC current

    Hi Allvol, I don't know why Draggy measured ripple on his battery's voltage and I don't know its cause or its frequency. Sometimes his ripple's amplitude is impossibly huge. I think his meter is playing tricks on him.
  12. audioguru2

    [help] Getting pure DC current

    The battery has an internal resistance. Therefore its voltage fluctuates (AC) with changes in load current. A huge supply bypass capacitor will help but a higher voltage and a voltage regulator IC that has an extremely small internal resistance will fix the fluctuations.
  13. audioguru2

    Digital radar speedometer

    The Ramsey radar gun kit is only good enough for a kid's science fair demo?
  14. audioguru2

    HELP - resistors and dip-switch

    Pin 6 of the 555 is a triangle wave that feeds an input of the comparator. It is a sensitive spot and its frequency is affected a little by the resistance and capacitance of the frequency counter in the DMM.
  15. audioguru2

    [help] Getting pure DC current

    Your microcontroller should work fine on a supply of 5.8V, and a small bypass capacitor. It would get too hot if it had floating inputs, a clock frequency much too high or if it is driving a short. Attach your schematic for us to see what is wrong.
  16. audioguru2

    Digital radar speedometer

    A micro-stripline is a way of wiring microwave RF parts so that the plumbing forms tuned circuits and impedance matching devices. I have never played with frequencies as high as microwaves so I don't know anything about it. A search in Google might find a description about how it works.
  17. audioguru2

    100W Amplifier Help

    Hi Zak, You can't bridge two of these amps without blowing them up. A bridged amp must handle twice as much current as a single amp, for the same speaker's impedance. It is easy to calculate the approximate power out of an amplifier. Yours has an 80V supply. Its darlington output transistors...
  18. audioguru2

    [help] Getting pure DC current

    Super Heavy Duty cells are cheap garbage, use alkaline cells. Then the cells are not new or can't pass the current. 12.2VAC is impossible from a 6V battery. Your meter is picking up interference. It doesn't matter because something is wrong with the meter or the way it is connected. 1000uF is an...
  19. audioguru2

    relay question

    Your relay has a 12V coil and might be made by a company called "Nais". You don't know the rating of its contacts so what good is it? It might be a fire hazzard if you use it to switch the mains.
  20. audioguru2

    [help] Getting pure DC current

    A 0.1uF capacitor is much too small as a supply bypass capacitor. With a new battery that has a 1 ohm internal resistance it will reduce supply ripple to half at 1.6Mhz. 1000uF will reduce supply ripple to half at 160Hz. What circuit do you have that has a high output current and a low amount...
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