Author Topic: Optimum DRO  (Read 919 times)

Offline Corrado

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Optimum DRO
« on: September 07, 2018, 01:49:28 PM »
I am having problems with my Optimum DRO.
I've only just started to use it.  The screen sometimes fluctuates whilst in use and then loses accuracy by about a millimetre when I try to go back to a specific point.
It was tested at the Dealer and swapped under warranty.
The second one is doing the same. Is anyone else having this issue with this DRO ?

Offline Admiral_dk

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Re: Optimum DRO
« Reply #1 on: September 07, 2018, 08:59:21 PM »
I got no experience with that type unit - but as en electronic tech, my first suspicion is the power supply  :zap:
and since it has been swapped once before, I would guess the power cable. Just about a week ago I once again tried to test a piece of equipment that behaved erratic and found the cause to be a big power socket at the end of the cable pushed into the male IEC connector (found on computers, heaters, etc.) that had skinny pins  :Mad:

This is actually not design flaw in the connectors, but me not noticing that I was putting an IEC C15 cable into the IEC C13 socket as they look almost totally identical and it will often work (or kind off). The problem is the pin size in the C15 (kettle plug) is bigger than the C13 (computer plug) so you get an intermittent connection. The C15 cable can always be put into the C13 socket, but not the other way around.

The problem could be somewhere else, but I would still check the whole power chain from outlet to the DRO and maybe even from the fuse box.

Offline bent

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Re: Optimum DRO
« Reply #2 on: September 10, 2018, 06:40:14 PM »
I had trouble with my cheap DRO's (magnetic rail sensors, from China) and figured out that random power fluctuations were causing the issue.  Realized after awhile that having the garage beer fridge on the same circuit was causing the problem - the compressor for the fridge would kick on, and the numbers on the screens would flicker once and come up different.  So, when machining, I try to remember to pull the cord out for the beer fridge...then remember to plug it back in again... :DrinkPint:

Offline Baron

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Re: Optimum DRO
« Reply #3 on: September 19, 2018, 08:28:28 PM »
Hi Guys,

There are two sources of interference that can upset DRO's. Conducted and radiated, each has its own method of reduction.  Sometimes both combine to cause problems that do not succumb to one cure or the other.

One way of reducing radiated interference, is by screening.  That is putting a conductive barrier between the DRO and the source of the interference.  Screened cables is one, putting the electronics in a conductive metal box could be another.

Conducted interference can be reduced by filtering.  This could be as simple as wrapping the power lead through a ferrite ring, or using a ferrite clamp on the cable.  Or as complex as inserting filtering devices in line with the actual power cable.

There are a number of techniques that can be used to help determine what type of interference is causing the problem.  For instance running from batteries, or putting the electronics in an earthed biscuit tin.

In one case that I know about, a simple modification to add a capacitor across the power supply inside the display solved the issue, another required the replacement of the motor brushes.

Best Regards:  Baron.

I donít regret the things Iíve done, I regret the things I didnít do when I had the chance.