Re: Oregon Micro/Mariss

Hi,

Well, since you asked...I designed all the CN series of drives:

CN4A24 SCR DC motor drive
CN0055 Linear DC motor speed control
CN0100 Linear amplifier microstep drive
CN0105 Switching type DC motor speed control
CN0121 4-quadrant switching DC motor speed control
CN0143 10 microstep drive
CN0153 Full half-step drive
CN0162 Up to 250 microstep drive
CN0165 Low iron loss, up to 250 microstep drive
CN0170 2 axis motion controller, circ. interp., Z-80 based
CN0172 Step pulse generator, accel, decel, base speed, max speed
CN0173 1 axis indexer
CN0182 Servo drive
CN0200 160V microstep drive
CN???? Many others I can't even remember

A lot of these drives were private labeled by OMS, NEAT, Superior
Electric, API, Pac Sci, and many others I don't recall anymore. Most
are not sold anymore except I think API still sells the CN0100 under
their own name for low EMI applications.

All of the drives were potted at the insistence of management in the
belief that would prevent "reverse engineering". All that did was to
make it nearly impossible to do failure analysis and product
improvement, or for that matter, recover process errors.

Here's an example. When EPA regs required phasing out carbon
tetrachlorine board cleaning, we switched to a Kester water-alcohol
de-fluxer. The boards now required hot soaking in this solution. They
were then promptly dried, potted and shipped.

About 2 months later many drives began to return from OEM customers
due to failures. The OEMs were not happy since at this point the
drives were out in the field and replacing them incurred expensive
service calls to the far corners of the earth.

The cause was the de-fluxer coupled with potting. Some of the
solution found its way into the glass to metal hermetic seal in the
diodes we were using, (1N914, DO7 package). The potting trapped the
solution there, which then procceded to corrode the diode's metal
leads until the metal salts created "poisoned" the diode and shorted
it.

It took a month of sheer panic to identify the failed part and the
cause; the potting insured I didn't have access to the circuit. The 2
month latency for the problem to manifest itself and the month it
took to identify it insured there were at least 2,000 drives out and
1,000 ready to ship with this fatal flaw. They all had to be junked.

To this day I hate potting. It is hard enough to design and maintain
a design without the added impediment of being blindfolded and having
your hands tied behind your back. I blame potting for my gray hair.

Mariss

--- In CAD_CAM_EDM_DRO@y..., carlcnc@s... wrote:
> Mariss
> that's 2 well known[that I know of] drives BEFORE the Gecko,
> makes me wonder where else your talents have been proven !
> Me thinks you are too humble !
>
> Carl