Recent content by Lou1

  1. Lou1

    Need help building off this schematic.

    Your second schematic doesn't look very healthy, I'd stick with the first. The 1K resistor has to be inserted between the output of the opamp and the gate of the mosfet. cheers
  2. Lou1

    Need help building off this schematic.

    Hi If you want a clean supply, it is probably a good idea to avoid switching regulators, despite the amount of heath the circuit will generate. Capacitors are OK for improving the noise performance, but chokes risk destabilising the circuit; I'd avoid them. An improvement to your circuit would...
  3. Lou1

    RF Audio/ Video Modulator

    Hi I suppose this modulator is intended to be used with a TV. In this case, all you have to do is to add the sound subcarrier signal (or more exactly, the sound intercarrier signal) to the video signal at the input of your video modulator. The sound subcarrier depends on your country: in Europe...
  4. Lou1

    Infrared

    Hi Here is a small primer on the subject to begin with: http://www.web-ee.com/primers/files/an1016.rev0.pdf
  5. Lou1

    RPM meter

    You could probably modify the design to extend its range: by adding a precaler or a supplementary counter stage. Lou
  6. Lou1

    Which capacitor?

    These would typically be plastic types: mylar (polyester), polycarbonates. Lou
  7. Lou1

    Help me in my VCO design please!

    You can use the following circuit with minor modifications (capacitors slightly larger and one or two more turns to the coil). http://users.cableaz.com/~cappels/dproj/FMVFO/fmvfo.htm In order to servo its frequency, you have to follow it with a frequency divider that brings the frequency to some...
  8. Lou1

    Frequency Detector

    Hi Dody What you intend to do is extremely complex and difficult! First, in order to detect simultaneously several frequencies in real time, you have to use some form of convolution process: a Fourier transform, f.e.. But , that's not enough, because each single vehicle will produce multiple...
  9. Lou1

    COLOR DETECTOR

    Hi I think you'll need three detectors: one barrier type, detecting any ball including the black one and two reflective type. One will have a red LED as a source and will react to white and red balls, the other will have a green LED as a source and will only react to the white ball. By...
  10. Lou1

    What is Switched Capacitor D/A converter

    Hi Here is something that's probably closer to what you're looking for: http://microsys6.engr.utk.edu/ece/bouldin_courses/652/tutor6.pdf Lou
  11. Lou1

    Reduce output Voltage of Power Supply

    Hi Robert I think it is perfectly possible to reduce the ouput voltage of these supplies to 12V, but you won't succeed by overloading them with a bleeding resistor. What you have to do is to tamper with the voltage feedback servo loop. I don't know specifically these supplies, but you should...
  12. Lou1

    Sound activated NE-2

    Hi You can try connecting one side of your NE-2 to ground via a 100pF capacitor and use the other end to probe various points of the transmitter (maybe the antenna) until you find the right spot. Lou
  13. Lou1

    random select

    Hi A frequently used solution for this type of problem is a fast, free-running counter (either in hard or soft form) that is read when you need your random number. Although it isn't a true random number generator, it is generally sufficient because the statistical repartition is OK and you have...
  14. Lou1

    CFL Inverter

    Hi Have a look at this page : they have simpler, cheaper circuits and the transformers are fully specified. http://www.zetex.com/3.0/3-8-1a.asp Lou
  15. Lou1

    Log voltmeter

    Thanks Oli and MP, but what I want is precisely to avoid a separate log converter; I know that the DVM chip is able to implicitly perform the conversion, but I don't remember the trick. Lou
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