On Mon, 14 Apr 1997 19:45:16 -0500, Phil Clements
<philk5pc@connect.net> wrote:
>At 08:13 PM 4/14/97 -0400, you wrote:
>
>>anyone know the current draw of the tube at 5.0V? I want to use a
>>resistor in series with the filiment to get the voltage right ... or
>>should I put it in the transformer primary?
>>
>I put my resistors in the primary..this serves as a soft-start also, limiting
>the initial surge current on the filament of the 8877. I had to use a resistor
>in the secondary of my Alpha 77SS because it doesn't have a seperate filament
>transformer. The 8877 draws 10 amps @ 5v.
<><><><><><><><><><><><><><><><><><><><><><><><><><><>
Another reason to put the dropping resistor in the primary is that the
value needed will be much easier to find. In the secondary, you might
need a value in the tenths of an ohm range, but in the primary, it
would typically be in the 5-50 ohm range. Much more common.
73, Bill W7TI
wrt@eskimo.com
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