Autoformer issue

wa8yxm wrote:

I am not sure if the Autoformer is an Autotransformer or a tapped transformer.

Hughes actually claims it's not an autotransformer, in as much as it has separate line and load windings. In my opinion, and from what all I can suss out about how they're constructed, Hughes is being misleading in making that claim: while the transformer itself presumably does have separate windings for the input and output, the two sets of windings are connected together when it's in use and so wired in an autotransformer configuration. (Buck/boost transformers are pretty standard components used in e.g. some industrial installations, and there's nothing to suggest that the Hughes device is anything much different than one of them along with some associated switching circuitry.)

I think their response to the recent NEC changes that prohibit autotransformers for RV park use is also rather telling. They have come out quite vocally against these changes, saying basically that they are pointless and senseless and were promoted by parties with less than pure motives, and then continue on with "but they don't apply to our products anyhow." While the first bit may well be true, and I tend to agree that it's a rather bizarre restriction as stated, why would they be so vocally against it if they were certain their product was not affected by the new code?

(As an aside, the NEC has long had a prohibition on the use of autotransformers in RV converters which at a casual glance might seem to apply a little more broadly. That's unrelated to autoformer/voltage booster use.)