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  1. C

    oscillator help

    The collapsing magnetic field of the inductor makes the collector-end of the coil more positive and this is transferred to the emitter to turn the transistor OFF. Where is the capacitor across the coil that sets the rate of collapse?
  2. C

    oscillator help

    The second problem with your circuit is this: The feedback capacitor is designed to turn the transistor OFF. Its effect is severely limited by pushing against 1,000p. What effect do you think 20p will have against 1,000p??? A transistor can be turned ON by holding the emitter firm and driving...
  3. C

    oscillator help

    If you are saying C in the tank circuit is 20p, the frequency of oscillation will be higher than 200MHz. The feedback capacitor should be no more than 5p so your figures are way off suitability. Simply build you circuit and see it does not work.
  4. C

    oscillator help

    "Of course, there is a cap in parallel to the inductor. As a consequence, we have a tuned circuit, which determines the oscillator frequency." You say this because you don't understand capacitor values. Once you insert capacitor values you will see how wrong you are.
  5. C

    oscillator help

    "The effective capacitor across the coil is the one from collector to emitter." Where do you get this from????? This is ENTIRELY INCORRECT. The cap from collector to emitter is the FEEDBACK capacitor.
  6. C

    Tilt Angle between two LDR

    You really need to attend 3 more years of your Bachelors Electronics classes before you can entertain the possibility of designing the type of circuit you request.
  7. C

    oscillator help

    It's much easier to make a 98MHz osc because you can pick it up on FM. You really need a cap across the coil to make a reliable osc. See FM Transmitters and Spy Ccts for circuits
  8. C

    7-segment display 3-to-8 decoder logic circuit (please help, thank you)

    I understand what has to be done. All you have done is create a table of the requirements. I call the output a "random"sequence because it does not represent any logical increment or decrement. No-one has come up with any way of creating this random sequence.
  9. C

    7-segment display 3-to-8 decoder logic circuit (please help, thank you)

    "If the answer was simple, someone would have provided the answer by now." "I think they have." I don't see anything close to an answer. Where is the "random" number generator.
  10. C

    question about reading voltage

    A lot more information is needed. Many power supplies have a higher voltage so that the voltage drops to say 22v when fully loaded.
  11. C

    Delayed buzzer for Motorbike

    If you haven't enabled the chip, are you sure you can reset it. The chip has input protection diodes to handle 1mA
  12. C

    Delayed buzzer for Motorbike

    Whats the purpose of D2 D3 R1 and C3 ???? Just a simple transistor on the output would be needed as the beeper takes less than 100mA
  13. C

    7-segment display 3-to-8 decoder logic circuit (please help, thank you)

    Firstly, if the answer was simple, someone would have provided the answer by now. It has already been 1,237 minutes since the question was asked. Secondly you are only providing part of the answer. The simple part. I could have done that in a twinkling. How are you going to produce the odd...
  14. C

    Impedance of two stage amplifier

    "Or like saying that there are 39.37 inches in a meter, or that the speed of light is 299792458 meters per second. " You have absolutely no idea what I am talking about. Transistors have tolerances of +/- 50% and values change according to the temperature and even the supply voltage. It is...
  15. C

    Impedance of two stage amplifier

    Coming up with an absurd value of 33.8 is like saying I am going to drive at 101.3 km per hour for the next 37 minutes.
  16. C

    7-segment display 3-to-8 decoder logic circuit (please help, thank you)

    An absurd request like this simply needs a microcontroller and no messing around. The secret in life is to do something without having any intelligence and without having to do any thinking. Look at all the multi-millionaires.
  17. C

    BOSCH reputable car battery manufacturer? then where are datasheets?

    You have obviously never repaired any of their hyrogenerator gas hot water systems. Neither have you pulled apart one of their starter motor solenoids.
  18. C

    BOSCH reputable car battery manufacturer? then where are datasheets?

    BOSCH stuff is very poor quality. I have had to fix their gas heaters, work on their starter motors and many other items. They have NO design department where you can provide improvements or talk to anyone with any knowledge.
  19. C

    BJT Output Stage

    That circuit will blow up. Good luck.
  20. C

    Is this device a thermistor?

    Measure its resistance and this will eliminate a number of possibilities.
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