Wardenclyffe Tower

Discussion in 'General Electronics Chat' started by Art, Feb 6, 2014.

  1. Art

    Thread Starter Distinguished Member

    Sep 10, 2007
    785
    61
    Hi Guys,
    Was this the general idea?

    ps. I assume there was some gizmos between the supply and the coil because
    the frequency for the coil may not have been intended to be the mains frequency.

    [​IMG]
     
  2. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    there was a spark gap transmitter to feed the tower. there were also ultraviolet searchlights on the top of the tower. there was a very long grounding structure under the tower. not sure if the spark gap transmitter was of the quenched, rotary, or other type.
     
  3. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    Probably not. The gap between the ionosphere and earth could possibly be seen as a capacitance but not as an inductance.

    By the way, your original post could do with the addition of some background information for context. Not everyone will know you're referring to the lab, experiments or theories of Nikolai Tesla.
     
    Last edited: Feb 7, 2014
  4. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    the tower was supposed to excite the schuman cavity aprox 8 hz. between the earth and ionosphere.
     
  5. Art

    Thread Starter Distinguished Member

    Sep 10, 2007
    785
    61
    I don't want replies in that case.

    That sounds familiar, I'll have to look into it.

    I'm not trying to reproduce anything of this scale, just to understand.
    One day, I would like to produce a Tesla "display" coil though.
     
  6. tcmtech

    Well-Known Member

    Nov 4, 2013
    2,042
    1,674
    At 8 Hz was the Wardenclyffe power transmitter spark gap driven or was it alternator driven?

    To me for that low of resonant frequency it would make more sense to have driven it via a massive low frequency alternator system.
     
  7. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Especially given Tesla's love of rotating/alternating mechanisms and desire to tune resonant frequencies.
     
  8. Art

    Thread Starter Distinguished Member

    Sep 10, 2007
    785
    61
    I suppose a solid state, or even vacuum tube osc were out of the question back then :)
    I heard he used his mechanical osc (earthquake machine) for many experiments,
    as there wouldn't have been too many options.
    Apparently that machine just vibrated a coil with the machines vibration.
    It stands to reason that either a fixed magnet with floating coil would provide an oscillator.
     
  9. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Yeah he liked mechanical systems too. So the mechanical coil oscillator has a freq dependent on simple mechanical tuning like tweaking the spring tension and contact position etc.
     
  10. Art

    Thread Starter Distinguished Member

    Sep 10, 2007
    785
    61
    That would be a funny clock source for a micro circuit RB :D
    a hundred times the size of the micro circuit itself!

    Coming to think of it you could probably make a pickup for 50Hz from mains that way,
    if you were doing something that could run slowly like a timer.
     
  11. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Funny enough I have wanted to do a "50 Hz clocked PIC" for years now.

    With full wave rectified mains that gives 100Hz for the PIC external clock, so it equals 25 PIC instructions per second execution speed.

    I'm sure a workable HH:MM clock can be built at that speed, but it would take some fancy coding to make a HH:MM:SS clock with only 25 instructions per second. An interesting challenge for sure. :)
     
    KJ6EAD likes this.
  12. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
    463
    the most pervert clocking i have done so far was to gate off from a dc/dc booster IC with a 12k resistor. Running a small LED chain, I never observed variation of the speed.
     
  13. Art

    Thread Starter Distinguished Member

    Sep 10, 2007
    785
    61
    I don't know if that's possible even with seven segment drivers RB,
    the change from 11:59 to 12:00.. you have to do the lookup for every digit.
    The only way around it I can see is a lookup table of huge memory that
    contains all digits for every possible time of day... then the EEPROM read time is another problem.


     
  14. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Maybe not?

    What's wrong with this (assuming 4 ports and a 7 seg display on each port);

    call wait_minute;
    movlw mask1 ; 11:58
    movwf portA
    movlw mask1
    movwf portB
    movlw mask5
    movwf portC
    movlw mask8
    movwf portD

    call wait_minute;
    movlw mask1 ; 11:59
    movwf portA
    movlw mask1
    movwf portB
    movlw mask5
    movwf portC
    movlw mask9
    movwf portD

    call wait_minute;
    movlw mask1 ; 12:00
    movwf portA
    movlw mask2
    movwf portB
    movlw mask0
    movwf portC
    movlw mask0
    movwf portD

    so apart from the 1 minute timer it takes 8 asm instructions to create AND display the time.

    Then looking at that you can simplify to;

    call wait_minute;
    movlw mask8 ; 11:58 (only 1 digit changes this minute!)
    movwf portD

    call wait_minute;
    movlw mask9 ; 11:59 (same!)
    movwf portD

    call wait_minute;
    movlw mask2 ; 12:00 (3 digits change here!)
    movwf portB
    movlw mask0
    movwf portC
    movlw mask0
    movwf portD

    That would take very little in the way of asm instructions PER MINUTE to make a HH:MM clock. :)
     
  15. markdem

    Member

    Jul 31, 2013
    82
    38
    Not sure if it is cheating or not, but just use a PLL to multiply the 50Hz to something more user friendly.

    Have Fun
     
  16. Art

    Thread Starter Distinguished Member

    Sep 10, 2007
    785
    61
    Oh man that's a huge amount of program memory still!

    markdem, yes although much cheaper than a crystal,
    I think it's cheating if the idea was some absolute minimalism ;)
     
  17. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    digital clocks have been made for years using the line frequency for time base. 50 Hz devided by 50 is 1 Hz. a little more dificult here, 60 Hz devided by 60 is 1 Hz. why would a pic chip or mcu be necessary?
     
  18. tcmtech

    Well-Known Member

    Nov 4, 2013
    2,042
    1,674
    Full wave rectify your mains and you get 100 or 120 Hz for a base frequency. Use a simple resistor and capacitor to couple that frequency base through a second full wave rectifier and you get a 200 or 240 hz base frequency to work with.

    Run that through a simple comparator circuit to clean it up and make a nice clean clock pulse train and you're good to go and should have plenty of clock steps to work with during every second.
     
Loading...