It's time to restore the 11/45.
Marc Howard
cramcram at gmail.com
Thu Feb 5 12:24:15 CST 2015
Where do you guys find these 11/45's? I'd love to get one someday. Is
there an PDP-11 outlet mall I missed somewhere?
Marc
On Thu, Feb 5, 2015 at 9:46 AM, Jon Elson <elson at pico-systems.com> wrote:
> On 02/05/2015 10:27 AM, Noel Chiappa wrote:
>
>> > From: tony duell
>>
>> > A plain Variac does not provide isolation from the mains so you are
>> > actually now working on mains-connected circuitry (read :
>> dangerous and
>> > you can't clip a 'scope on it).
>>
>> I'm clearly a little slow this morning: why can't you use a 'scope on it?
>>
>>
>> Because the equipment under test is connected to the mains. A bridge
> rectifier is
> between the AC input and the rest of the circuitry, therefore there is no
> part
> of the EUT that is at neutral potential, and if you hook up a grounded
> scope, you
> will have fireworks. Floating a scope above ground should be reserved for
> the
> most special cases where you are testing line-powered gear that MUST not
> run on an isolation transformer, for some reason.
>
> Jon
>
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