# [Amps] peak voltage rating for load cap

Vic Rosenthal k2vco.vic at gmail.com
Sat Aug 19 10:52:24 EDT 2017

```All of you guys are forgetting that he said "PI-L", not PI!

Vic 4X6GP

> On 19 Aug 2017, at 16:29, Peter Voelpel <dj7ww at t-online.de> wrote:
>
> Let´s say the SWR is 3 then the load might be 150 ohms.
> The peak voltage across the load capacitor will be 775V at 2KW.
> That is sqrt3 higher then at SWR1.
>
> 73
> Peter
>
>
> -----Original Message-----
> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Joe Subich,
> W4TV
>
> That will give you average (RMS) voltage with SWR = 1:1.  For peak
> voltage, multiply by 1.414 (peak voltage of a sine wave):  316 * 1.414
> = 447 V.
>
>> your system is all tuned and matched.
> Multiply the peak voltage by the SWR for worst case peak voltage if
> the voltage node occurs on the capacitor - 316 * 1.414 * 3 = 1340V.
> A 1200 volt rated capacitor will be marginal in a *system* allowing
> for a maximum SWR of 3:1 at 2 KW - it will be barely adequate when
> the system is designed for 1500 W (1166 V).
>
>
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```