Search results

Search Forums New Posts
  1. Arouse1973

    Help debug DC/DC buck converter

    Yeah think I see where Steve's going. The diode is rectifying the noise from the coil and charging up the capacitance of the circuit which is why a small load is going to show this up. Adam
  2. Arouse1973

    Simplest antenna for 5.8GHz 200mW transmitter to allow 100M range

    Don't you mean winding up his keyboard :)
  3. Arouse1973

    A new type of BLDC motor drive?

    What you need is Harald's cheap Air Con circuit, that should power it just fine.
  4. Arouse1973

    Some help on bypass and filtering needed.

    This is what I do. For every IC I use a 100nF capacitor X7R ceramic and a 10uF multilayer ceramic as close to the power supply pin as possible. Now most people use a large capacitor on the input also, this can give you issues if your power supply is being used with longish cables. You can get...
  5. Arouse1973

    Half Bridge Converter Question

    The first circuit has a few issues but it is probably the best out of the two. What's missing. 1) suppression diodes for the coil. 2) Anti flux walk capacitor in series with the coil. This is one of the most popular configurations for high voltage and high power SMPS. The reason is you...
  6. Arouse1973

    Help debug DC/DC buck converter

    How big are your super caps? They might be loading the output? Adam
  7. Arouse1973

    oscillator doesn't oscillator as I expect

    Nope, the LC combination is what sets the frequency and the other capacitor is what controls the common base configured transistor drive. You wouldn't normally use a choke for this, the name gives it away a bit CHOKE. I think the type you have used are designed to have a low Q which is normally...
  8. Arouse1973

    Purpose of a cap in a circuit...??

    Unfortunately this might be some of the reliability issue you can get with 555 timers and why I never use them.....but we won't go in to that, I'll only get in trouble again :). If your design is a proven design and is built correctly and all care has been taken to clean the PCB to remove...
  9. Arouse1973

    Servo Controller Help

    I agree with John, most analogue servos require approx. 20ms period which is 1/20ms=50Hz Adam
  10. Arouse1973

    mV voltage reference for a comparator

    Ok just do as Harald said but forget the gain at the front end and then add another summing stage. Then sum the outputs of each sensor into a suitable op-amp and add gain there if you need it. Adam
  11. Arouse1973

    Servo Controller Help

    RC servos require a break between pulses of around 6-20ms depending on the type of servo 20ms is a quite standard frame rate. This could be your problem. Adam
  12. Arouse1973

    oscillator doesn't oscillator as I expect

    Are you sure that's a 4.7mH inductor. Looks like a small choke to me. The circuit configuration shown is normally used for high frequency and not 160Khz. Adam
  13. Arouse1973

    Oscillator circuit - possibly Wien Bridge Oscillator?

    Look at the position of C1, clue is it is in the wrong place. Make sure you are using the correct type of OP-amps, look up single supply and rail to rail OP-amps. Adam
  14. Arouse1973

    How does a vaporizer actually work?

    Do you mean from star trek or blakes seven or red dwarf. There is a difference. Kris might know if doctor who has one also. What do you mean? Adam
  15. Arouse1973

    Hi from Scotland

    Get on. Adam
  16. Arouse1973

    How do I build a Metal Detector?

    What they keep asking stupid questions or what?
  17. Arouse1973

    Best way to drop power supply output voltage by 1-2V

    That seems quick. At 0.7c which is recomended it should take about 2.5 hours from flat to charged. The first cc charge charges to about 55% and then the rest is cv for another 2hours ish until about 3% of the initial 0.7c current. I would say your battery was not flat and it was not putting...
  18. Arouse1973

    Indicator LED placement

    Yep that's correct. Thanks Dave :)
  19. Arouse1973

    How do I build a Metal Detector?

    Private message SPAM. does that go on, blimey.
  20. Arouse1973

    Best way to drop power supply output voltage by 1-2V

    The 1N5004 seems to be rated at 1A and you want 1.3A. I would look for another diode. The thermal resistance of the diode give you the rise in centigrade per watt. Times this by the watts and add ambient and that's how hot it will get. So say the diode had a 20deg/watt thermal resistance and you...
Top