[Amps] Step Start on a 3KA Amp

[Ian White GM3SEK]

Bob Maser wrote:
>Can anyone tell me what good is it to have one of those cone heaters in
>series with the primary of the plate transformer?  When the cone heater is
>in the circuit, the secondary voltage is 2800VDC and when it is shorted out,
>it is 3000VDC.  Hardly seems worth the effort.  The cold resistance of the
>cone is ±30 ohms.

All the good happened in the first two or three mains cycles, when the 
resistor limited the surge current to less than 8A (<240V / 30 ohms).

By the time you can see anything on a meter, the surge is over and the 
resistor can be switched out.


-- 
73 from Ian GM3SEK