[R-390] Question about VARIAC

[2002tii]

Barry wrote:

>I would like it to swing just the line voltage and no more.
>
>Would it be advisable to connect the input across the entire 292 turns
>instead of 249 (292-43)?  I know this would give me no more on the output
>than the intput voltage, but am wondering if this would be harmful to the
>VARIAC.

It's just an autotransformer with a variable tap.  The variable tap 
sweeps all 292 turns, so if you connect the line across all 292 
turns, the variable output will sweep from 0 V to the line input 
voltage.  This is a very common variac connection, so unless there is 
something very unusual about that particular one (like, the laws of 
electromagnetism don't apply to it), it should work fine.

>I assume the other tap would be used so that the direction of
>the knob can be changed (e.g. CCW would increase the output voltage instead
>of decreasing it).

Yup.

Best regards,

Don