[Amps] soft start, how to determine if needed?

[Jim Brown]

On Wed, 24 Feb 2010 09:21:39 -0300, Felipe Ceglia - PY1NB wrote:

>Is there a way to calculate what R values and relay contact Amp rate 
>should I need?

The power supply for the Ten Tec Titan 425 (1980 vintage) uses a 20 ohm 25W 
resistor in series with one side of the primary. I haven't one apart for a 
while, but I recall the relay contacts looking like 10-20A or so. 

>Also, if the primary is feed with 110+110 volts, I should use one R on 
>each primary leg winding, right?

No, only one side. The transformer is not ground-referenced, it is driven 
between hot and hot. 

73,

Jim K9YC