Re: 577 AC collector supply not reading zero on display
Google US patent 2,009,013.toggle quoted messageShow quoted text
It was a case study in a course in an engineering curriculum, taught by R.H.
Rines, son of the patent attorney.
Yes, Rines of Nessie fame.
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Roy
Sent: Tuesday, December 10, 2019 3:00 AM
Subject: Re: [TekScopes] 577 AC collector supply not reading zero on display
I have seen Variac brushes that were not point shaped at the contact but
rather had s linear shape. The contact end was as long as the brush diameter
but narrowed along the sides so as to contact the full length of the
flattened portion of one or two windings.
Without examining any of the ones here, I suspect they do contact more than
one winding if positioned between two wires in order to create smooth
transition from one winding to the next.
I do have one very old GR Variac whose brush is simply round, and is flat on
the contact end. It may date from the 40's or even 30's.
On Dec 9, 2019, at 10:57 PM, DW <wilson2115@...> wrote:and the variac works throughout its full operating range other than not
going to zero. Therefore I been convinced the variac as far as the winding
I believe he is on to something about the contact point being worn down
widening the contact area and potentially causing what I am experiencing. I
will try to rework the brush to a point with some sand paper and see if I
notice any improvements.
being useful for someone with collector supply issues to check the wiper