[Amps] SCR to adjust 240v to 200v

[Jim Brown]

On Sat,8/13/2016 8:11 AM, Jim Durham wrote:
> I am using a Variac, which does the same thing and also allows me to 
> adjust the input AC voltage.

What it does that is the same is that it adjusts the primary voltage. 
But it is VERY different from a boost/buck transformer, because it must 
be rated for the full VA of the load.

A boost/buck transformer requires that the primary be rated for the line 
voltage, but a much smaller current. Only the secondary must be rated 
for the full load current. The result is that a good boost/buck 
transformer is a much smaller and lower cost solution. All of them that 
I have seen are multi-tapped and are clearly marked with voltage and 
current ratings and their  turns ratios, so it's almost trivially easy 
to choose one and hook it up.

73, Jim K9YC