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  1. C

    Inductor/power supply choke operation

    Say you have a 12v power supply with no ripple. And say you have a big inductor. When the 12v enters the inductor it produces magnetic flux and it emerges as 12v (or very close to 12v). Say you have a 12v power supply with 100mV ripple. When the 12v enters and starts to rise, it produces extra...
  2. C

    tuned (tank) circuit, oscillator, Q

    Colin do you agree that L and C do not need to be matched, provided that material is not a matter and provided we can ignore losses? What is your reason for not matching the two components?
  3. C

    tuned (tank) circuit, oscillator, Q

    What I am trying to emphasis is this. You are talking to beginners and talking about "circulating current" infers that current is circulating around and around the the two components. Current (energy) is added to the circuit on each cycle and is then passed to the inductor and back to the...
  4. C

    tuned (tank) circuit, oscillator, Q

    The mere fact that you can detect radiation and get a signal some metres from the circuit proves the losses to be considerable.
  5. C

    tuned (tank) circuit, oscillator, Q

    "In fact, once the circulation starts, the exciting voltage can be disconnected and it will circulate the current forever" Yes, the current does circulate AFTER the applied voltage is removed. But when it is oscillating, the energy is topped up during each cycle. The energy is added during...
  6. C

    tuned (tank) circuit, oscillator, Q

    To start with, there is no "circulating current." The tuned circuit is "topped up" on each cycle by the circuit (transistor or IC) and the current passes from the inductor to the capacitor and is then topped up again via the circuit. You imagery of a "circulating current" does not exist...
  7. C

    tuned (tank) circuit, oscillator, Q

    Ratch I don't know what you are talking about, and neither do you.
  8. C

    Inductor/power supply choke operation

    If you are talking about an inductor (choke) in a power supply, it needs to have an air gap. Suppose you put an inducotr on a car battery and illuminate a globe. Current will flow through the inductor and produce magnetic flux. You can prove this by opening up the inductor and picking up a...
  9. C

    tuned (tank) circuit, oscillator, Q

    Basically the "Q" of a circuit is the voltage across a coil when energy (current) is being delivered to it, compared to the voltage it produces when the current is turned off. In most cases for a tuned circuit, the Q is 2 because the voltage applied to the coil (inductor) is approximately equal...
  10. C

    tuned (tank) circuit, oscillator, Q

    "Somehow I'm not so sure about this and very few sources on the web mention that the inductor and capacitor shall be matched so that the respective amount of energy they can each absorb is close to equal."" That's the very thing I say in my discussion. To get an even width (similar width) for...
  11. C

    a small doubt

    Look on talkingelectronics.com website and Google for Flip Flop
  12. C

    PIC 16F676 problem

    "There is another school of thought that says the rate-of-change of voltage across the coil changes if metal is present. So this experimental detector is to test out that theory by measuring the time taken for the voltage across the coil to reduce to some specific level," That's for a big lump...
  13. C

    PIC 16F676 problem

    "What received signal?" I thought you said this what supposed to be a metal detector. "Surely, that was what my test program did?" I thought you said the LED was not fitted.
  14. C

    PIC 16F676 problem

    We are not worrying about pulsing the coil. We are worrying about picking up a received signal. The first thing you do is create a program that just turns on a LED when the switch is pressed.
  15. C

    Making PCBS

    It's all cheaper to get the boards made in China with an overlay, solder mask and tinned lands. I stopped making PCB's 40 years ago as they look atrocious.
  16. C

    PIC 16F676 problem

    It is a very insensitive circuit because the chip can only detect 1mV whereas a transistor can detect 0.001 mV.
  17. C

    PIC 16F676 problem

    bsf STATUS,5 ;Select Bank 1 movlw b'101111' ;set port A in/out movwf 85h movlw b'000110' movwf 95h ;pullups on 1 & 2 bcf STATUS,5 ;select Bank 0
  18. C

    Radio Reciever Circuit

    It's just a junk circuit with almost not output.
  19. C

    dc motor questions

    "But it will probably only run properly for 30 minutes." Where do you get these absurd predictions for a 35mA load ?????
  20. C

    LED Strips Display driven from 555 / 4017 counter

    The LED strip is 99 cents on ebay !!!!!
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