Quote:
Originally Posted by Paul Haese
Gary, the base of the heat sink is the fixing point for the ground or earth cable. The instructions for fixing this are outlined in the Scope Dome manual. It says to fix at that point.
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Hi Paul,
Yes, very good. Appreciate that. However, as grounding systems are usually a matter of compromises, could
you please paint me a picture with just a few words as to where specifically
the cable went to reference ground and roughly how long was the cable? For example, did you strap it to
the protective earth (PE) connection on the motor side of the inverter or all
the way to the ScopeDome USB box or to somewhere else?
Quote:
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I will get a choke today and fix the tag of the shielded cable to ground point on the inverter. The filter is another question though. I will have to look around for one of those.
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When you Google for the specific model of line filter the manufacturer recommends
you don't get a lot of hits so it will probably coming down to finding another
brand at the right performance/price point.
Your post yesterday whilst I was composing mine gave rise to the possibility of
a power integrity issue.
On the regulated power supply you mentioned that was powering
lots of other things like your cameras, is it a fancier one with a built-in volt
and ammeter or have you happened to measure the typical DC current draw
with a multimeter that the appliances connected to it were drawing?
Normally you would want the regulated power supply to be delivering
a steady steam of power from its own built-in bulk capacitance to ride out
any dips in the mains. In turn, each digital appliance should ideally be powering
itself from its own decoupling capacitors sprinkled across its own circuit board
and those being recharged by the board's own bulk capacitors. But if you
have a lot of thirsty horses drinking from the same shallow watering hole all
at once, it could deplete very quickly and with it your noise margins will
also drop, leaving them more vulnerable to any noise from, in this case,
the inverter-motor pair.
As you will be aware by looking at the inverter user manual, it has a very large
number of parameters that can be programmed and monitored. Some of them can
control attributes such as the acceleration and deceleration ramps.
As at start-up the motor will look like a short circuit and draw the highest current,
there might also be the possibility of re-programming some of the parameters
in the inverter via its front panel to make the inverter/motor pair draw less when
it starts and stops. You can even change the acceleration and deceleration
ramps to S-shaped and so on. In other words, there might be some parameters
that you can change in addition to the other steps you are taking in order
to mitigate the risk that that the inverter/motor disrupts the operation of something
else or induces noise into your imaging.
Once again, hope this is helpful and good luck.
Best Regards
Gary