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  1. ratstar

    Help with capacitor question.

    Its true. If you up the volts on the capacitor, it makes no difference to the workings of *ANY* circuit if the battery or power-source stays the same.
  2. ratstar

    I cant measure voltage on 100 picofarad capacitors on multimeter

    Maybe you could put a 1k resistor to the probe, then times the readings by 1000.
  3. ratstar

    I cant measure voltage on 100 picofarad capacitors on multimeter

    I'm actually making my own capacitors, so I dont know if they are functioning or not, I get farad readings out of them, but they are too small to test for real. If I hooked em up to an oscillator I can tell, because the led will turn on. So I've got an oscillator circuit on the way. :)
  4. ratstar

    I cant measure voltage on 100 picofarad capacitors on multimeter

    An oscilloscope could read the volts tho right, just multimeters cant.
  5. ratstar

    I cant measure voltage on 100 picofarad capacitors on multimeter

    Yes, thats what I was thinking. So to measure a picofarad cap you need a special kind of multimeter?
  6. ratstar

    I cant measure voltage on 100 picofarad capacitors on multimeter

    Its not in a circuit yet, I'm just charging the cap up with the power supply directly, the volt reading on the electrolytic is working, but the little ceramic cap is just displaying millivolts as if its not even charged up. The farad reading is about 100 picofarad, so what am I doing wrong?
  7. ratstar

    Need help with DC Dimming seven seg displays.

    I think it would be a photo resistor- when light hits it, it turns the transitor off - because it creates a direct connection to battery, so the base would miss out on current. :)
  8. ratstar

    I cant measure voltage on 100 picofarad capacitors on multimeter

    Is this because the power is draining out of the capacitor before the multimeter can read it?
  9. ratstar

    Fixing old 50ohm antenna

    yeh theres no ohmage on an antenna, the signal is so quiet nothing would get through a resistor - its got to go straight to the amp i guess. Maybe even adding a passive RC filter before the amp would kill it as well.
  10. ratstar

    AC->DC converter without a diode.

    Car stereos are amazing. Im a bit wierd tho, id like to make the whole thing from scratch, even the speaker! =) Not sure what it would sound like tho, but I bet it would be decent, avoiding the industry standard.
  11. ratstar

    AC->DC converter without a diode.

    Hang on, I think you dont need the capacitor, just add equal amounts dc to ac and then you get a rectified signal, no diode required.
  12. ratstar

    AC->DC converter without a diode.

    no probs then. ill just get back to my stuff, lots of work to do.
  13. ratstar

    AC->DC converter without a diode.

    Thats not low resistance, it should even work with microohm resistors :) voltage dividers work with micro ohms. It could be any amount of power here, not just the wall socket. Its just an idea, I know that just using a diode is easier and works better- but I was wondering if there was a...
  14. ratstar

    AC->DC converter without a diode.

    Heres a schem - It doesnt work yet. I think that maybe if supply power to the capacitor slightly in one direction - then it works maybe...
  15. ratstar

    AC->DC converter without a diode.

    If you put ac into a capacitor, and the discharge of the capacitor is the output. Then the ac will charge it from neutral to positive, then youll get a back charge from the ac, and this will make it go back to neutral again. (so then you dont get a negative half cycle!) The problem is, if...
  16. ratstar

    AD9850 Generate Random Fixed Frequencies Controlled By MEGA328P-AU

    So ur making it output a random frequency, whats not working about it? I'm not an expert with arduino's but I know a lot about programming in general.
  17. ratstar

    Need Help with simple 9V circuit design.

    Are MOSFETS an all or nothing event, I thought they were the same as bipolar junction, that they can accept an analogue input. I dont know tho, i'm not very experienced with transistors. Only ever got one to work once when I was amping up a photo-resistor into a motor, but it was actually...
  18. ratstar

    Need Help with simple 9V circuit design.

    You can run the motor off the potentiometer, but it has to go before the base of the transistor where the switch is, then its not seeing the high current.
  19. ratstar

    Direction of Current in AC circuits.

    god i hate electronics notation, cant understand anything from it.
  20. ratstar

    How to test buzzer

    if button then buzzer=off and start a timer that counts so long, then if timer=2seconds then buzzer=back on but ull have to get the button request to break out of that for loop that is running through the two frequencies. youll get it! welcome to hardware code. =)
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