Sine wave, polyphase motor systems are inherently damped
because of the sine arithmetic.
The problem with sine wave systems is it is hard to have
them locked into known ratios with other sine wave systems.
I need the zig-zag motion of the stylus, that spools out the
wire, to be in lock step with the rotation motion of the
coil form.
It is essential that each successive zig zag be laid down
exactly 1 wire diameter after the last. This gives added
grip to the wire, as it has to lift itself over the previous
zig-zag turn for it to slip.
In days of yor, this was done by using a variable ratio
drive, and a cam to move the stylus. The problem is it is
difficult to accurately set the variable ratio drive so that
the wire is laid out accurately, and to keep adjusting that
ratio as the coil circumference builds.
-Chuck Harris
Dave Wise wrote:
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Jim Ford suggested sine wave drive.
I think, How about a shaft coupling made of elastic material with damping??
Oh, now that I read ahead I see you're already thinking about it.
I am eager to hear about your continuing journey.
Wouldn't it be great if there was a sine wave drive system with electronic damping?
Dave Wis
________________________________
From: [email protected] <[email protected]> on behalf of Chuck Harris via groups.io <cfharris@...>
Sent: Monday, January 25, 2021 1:49 PM
To: [email protected]
Subject: Re: [TekScopes] 549 transformer question
I am working on it. I have an automated winder designed
and implemented... I still have some problems with wind
quality to resolve.
I use a micro-stepped stepper motor to directly drive the
former upon which the transformer is wound. The problem
is that even though it is micro-stepped 32x, the vibration
of the micro-steps damages the insulation on the wire...
leaving tiny creases every micro-step. The creases are
certain to be points of damage in the insulation integrity,
and are bound to cause arc-overs.
I am working on the problem from two ends, and hopefully
can solve it soon.
The winds the new machine makes are simply beautiful otherwise.
I hesitate to give any predictions, as I have been working
on this winding machine for 7-8 years. Life keeps getting
in the way.
-Chuck Harris
Joel B Walker wrote:
I have a very nice 549 that I have owned for nearly 35 years. It worked flawlessly at first, but then began showing the infamous epoxy HV transformer potting issue. Back when it started doing this ('87-'88) I had never heard of the epoxy problem before. I replaced the 6GE5, tested and subbed caps and diodes in the circuit to no avail. Of course the screen voltage on the 6GE5 was rising way over spec. so I knew it was being overworked. Spraying the Transformer with freeze mist would bring everything back to normal temporarily so finally decided the transformer must be bad.
In the last few years I have been reading about everyone's troubles with this same problem on many Tek scopes. I know Chuck Harris had been winding these in the past but has stopped. So the dreaded question is; Is he going to start back or is someone else going to start, is there a new solution, or are we all SOL?
