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Subject: Re: [Homebrew_PCBs] Re: drill pcb

From: rolohar@...
Date: 2016-02-29

Stefan Trethan:

I don't know how often the members of this group will encounter the type of industrial transformers that
you describe. But I do know that isolation (not insulation) is a factor to be considered,,,,,,,,,often when
connecting your test equipment up to equipment that you might be troubleshooting, designing, etc.

Refer to the conventional three-phase configuration that most of us encounter.

Regards,

Roland F. Harriston, P.D.


From: "Stefan Trethan stefan_trethan@... [Homebrew_PCBs]" <Homebrew_PCBs@yahoogroups.com>
To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, February 28, 2016 10:14:10 PM
Subject: Re: [Homebrew_PCBs] Re: drill pcb

 

Strictly speaking there are differences between an industrial control
transformer and an isolation transformer.
The isolation is often stronger with a dedicated isolation
transformer, sometimes the windings are even physically separated in
different chambers or on different shanks, instead of on top of each
other.
As a result coupling capacitance is lower with an isolation
transformer, but also magnetic coupling is worse.

So in some situations you may require an actual isolation transformer.

Many high quality control transformers fulfill the minimum
requirements for a safety isolation transformer, but always check the
datasheet.

ST

On Thu, Feb 25, 2016 at 5:15 PM, Brad Thompson
brad.thompson@... [Homebrew_PCBs]
<Homebrew_PCBs@yahoogroups.com> wrote:

> If you need to power a 120VAC item from a 240 VAC
> line (or vice versa), you can use
> a transformer ∗∗with isolated windings∗∗ designed exactly for this
> purpose. These are sometimes referred to as
> "industrial control transformers".
>
> 73--
>
> Brad AA1IP
>
>