Re: Rotor BPS

Subject:  Re: Rotor BPS
  Date: Thu, 5 Jun 1997 05:34:08 +0000
  From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
    To: Tesla List <tesla-at-pupman-dot-com>

At 04:40 AM 6/3/97 +0000, you wrote:
>Subject:      Re: Rotor BPS
>       Date:  Sun, 01 Jun 1997 10:03:00 -0700
>       From:  Skip Greiner <sgreiner-at-wwnet-dot-com>
>Organization: Greiner, Ltd.
>         To:  Tesla List <tesla-at-pupman-dot-com>
> References:  1
>Tesla List wrote:
>> Subject:  Re: Rotor BPS
>>   Date:   Fri, 30 May 1997 18:56:03 +0000
>>   From:  "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>>     To:  Tesla List <tesla-at-pupman-dot-com>
>>  In checking the input power to many Tesla coils on the Tesla List I
>> find
>> that they are underpowered. Increasing the BPS would only compound the
>> problem. Coilers apparently do not bother to do this important power
>> check
>> calculation. As a result they do not realize their coils are not
>> performing
>> well because they are under powered.
>>   John Couture
>Hi John
>Don't understand how increasing BPS will compound problem. Can you
>expand on this.

  Skip -

  The equation for the necessary wattage to power a Tesla coil is

      watt (secs) = (.5 Cp Vp^2)(BKS/EFF)

  where BKS are the spark gap breaks per second and EFF is the
(about .50). If there is not enough wattage the primary capacitor Cp
not be charged to the full primary voltage available. Note that this is
energy equation and there must be a balance for both sides of the
In other words if there is not enough wattage the capacitor will be
to less than the actual Vp available.

  If more breaks are added more wattage will be needed to fully charge
primary capacitor. This would mean that the capacitor is charged to an
lower voltage than the Vp available (to keep the equation in balance).
would compound the problem of the capacitor not being fully charged.

  Actually, the the primary capacitor charging process is quite
involved. As
I mention in one of my books, it involves the size of the capacitor, the
voltage Vp, the 10% cycle time,the effective resistance of both the
and secondary circuits (TC constants), the operating frequency, the
gap RPM, the rotary disk electrode radius, spark duration, etc. I have
to develop a computer program with these parameters but have not had
success. I have not heard of anyone who has fared much better.

  John Couture