# RE>Joules - Vrms or Vp (fwd (fwd)

```

---------- Forwarded message ----------
Date: 28 Jul 1998 12:28:06 -0700
From: Dale Hall <Dale.Hall-at-trw-dot-com>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: RE>Joules - Vrms or Vp (fwd

RE>Joules - Vrms or Vp (fwd)
Bart,
Good question ! Seems we all too often lack a statement of assumptions.

My first assumption in answering the question is that you want the energy
of each bang - most meaningful (not a peak or average bang though you could
do that calc, stating assumptions of methods/technique/rationale used)

The proper calculation will use the voltage that was measured on the Cap
just before as the gap fires as that relates the energy available for that bang.

Neither Vp (non resonant ?) or Vrms has much meaning here.
Vp is valid if only fired at the sine peak but would still need measured
as resonant charging would differ from non resonant.
Vrms would refer to an equivalent Vdc heating value and we want sparks
which relates to peaks.

Vcap may vary widely as a function of the gap type and time, consequently the Energy of each bang varies.  A perfectly synchronous RSG may come close
to providing a consistent set of  +/- Vcap voltages, repeating each cycle.

Do you scope your Vcap voltages ?

Useful is the maximum energy capacity of your cap:  1/2*C*Vrated^2
which is the maximum energy (joules) available per bang.
Of course practically, Vrated must be derated (risk/reward/life expectancy).

Dale

------------------------------
Date: 7/27/98 10:10 PM
To: Hall, Dale
From: List, Tesla

---------- Forwarded message ----------
Date: Mon, 27 Jul 1998 18:30:28 -0500
From: "Barton B. Anderson" <mopar-at-uswest-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Joules - Vrms or Vp

To List,

Regarding the calculation for Joules..... J = 1/2 x C x
V^2.

Should V = Vp or should V = Vrms? Why? (if you know).

All responses welcome,

Bart

```