[Amps] Step start

[Don Kessler]

On Sunday 03 February 2008 02:04:08 am Patrick Egloff wrote:
> Hi All,
>
> The purpose of a step-start is (mainly) to let the HV caps load smoothly.
>
> The "classical" way to make a step-start is to short the resistor in the HV
> transformer primary with a relay switched after a delay made with an RC.
> This delay is mostly arbitrary put to 1 or 2 s.
>
> Why not switch this relay with a divider from the HV voltage ? With the
> right divider, you ensure that the caps are really loaded and not supposed
> to be ?
>
> Just a guess...
>
> 73, Patrick.

I also thought that the step-start was to limit the inrush current to the cold 
filaments.  

Also -- The initial inrush current is sufficient to weld the contacts in the 
main power switch -- I've had to replace three main power switches on TL-922 
amps that didn't have step start installed because the power switch contacts 
had become welded together...