[GTALUG] mysterious restarts

[James Knott]

On 06/15/2016 03:46 PM, Stewart C. Russell via talk wrote:
> I've seen rotary converters on very old off-grid systems for remote
> power. Although somewhat inefficient, they output a true sine wave and
> survive misuse far better than solid state ones do. If smoke comes out
> of a solid state inverter, it's toast, but for a rotary, it's just its
> way of telling you to back off a little.

At work years ago, we had "no break power", where incoming AC ran a
motor connected to an alternator and an 8 ton flywheel.  When the power
failed, a clutch would kick in the diesel, with the flywheel maintaining
the power, while starting the diesel.  One problem though was the output
AC frequency was slightly low and threw off the real time clocks in the
computers.

>
> If you're lucky enough to get a tour of the IESO's HQ, they have a relic
> of the 25 Hz era on the wall. It's the display clock from the Shortt
> Synchronome pendulum clock they used to use to regulate the grid.
> Synchronomes are the most accurate mechanical clock ever made, and one
> has even been used (briefly, ill-advisedly) as an NTP server.

I haven't been to the headquarters, but I have been to the control
centre at Lakeshore & Winston Churchill several times.