Re: [Emc-users] Chasing noise

2017-08-15 Thread Gene Heskett
On Tuesday 15 August 2017 05:18:32 Les Newell wrote: > My LCR meter has an ESR function though I seldom use it. To be honest > I mostly just use it's resistance range for finding short circuits on > boards. It has a resolution of 0.1milliohms, not that you need quite > that resolution for finding

Re: [Emc-users] Chasing noise

2017-08-15 Thread Les Newell
My LCR meter has an ESR function though I seldom use it. To be honest I mostly just use it's resistance range for finding short circuits on boards. It has a resolution of 0.1milliohms, not that you need quite that resolution for finding shorts. It has fantastic resolution but so-so accuracy.

Re: [Emc-users] Chasing noise

2017-08-14 Thread Gene Heskett
On Monday 14 August 2017 14:08:00 Les Newell wrote: > Hi Gene, > > Sorry it took me a while to respond. > > > Re-reading this, Les, I have to ask how old that VFD is? > > > > Anything over 4 or 5 years, I would expect that the capacitors would > > be suffering from poor ESR, which isn't a test fea

Re: [Emc-users] Chasing noise

2017-08-14 Thread Les Newell
Hi Gene, Sorry it took me a while to respond. Re-reading this, Les, I have to ask how old that VFD is? Anything over 4 or 5 years, I would expect that the capacitors would be suffering from poor ESR, which isn't a test feature available on a utility DVM with a microfarads test function. It i

Re: [Emc-users] Chasing noise

2017-08-12 Thread Chris Albertson
Here is a much improved version, newer than mine. Also much better photos and description of functions. http://www.ebay.com/itm/2017-... Looks like the key eBay search term is "2

Re: [Emc-users] Chasing noise

2017-08-12 Thread Chris Albertson
> A gismo called a Capacitor Wizard, around $200 from a guy in Kansas City > does the definitive such test, measuring the equivalelent series > resistance, aka ESR, and any capacitor that reads over 2 ohms ought to > be replaced. While on the subject of test equipment. I just got one of these th

Re: [Emc-users] Chasing noise

2017-08-12 Thread Gene Heskett
On Friday 11 August 2017 02:29:36 Gene Heskett wrote: > On Thursday 10 August 2017 17:10:17 Les Newell wrote: > > Hi Gene, > > > > > I've had a heck of a time with noise when using a 7i90 interface, > > > noise so bad it destroyed several 7i90's by punching thru the 3.3 > > > volt circuitry. > > >

Re: [Emc-users] Chasing noise

2017-08-10 Thread Gene Heskett
On Thursday 10 August 2017 17:10:17 Les Newell wrote: > Hi Gene, > > > I've had a heck of a time with noise when using a 7i90 interface, > > noise so bad it destroyed several 7i90's by punching thru the 3.3 > > volt circuitry. > > That's some serious noise. Do you know where it is coming from? A n

Re: [Emc-users] Chasing noise

2017-08-10 Thread Jon Elson
On 08/10/2017 03:33 PM, Les Newell wrote: Also, common mode chokes on the DC INPUT to the 7i29 might be of help. The 7i29 doesn't have any big reservoir capacitors on board. I was always taught that H bridges need a nice low impedance supply. Adding inductance doesn't strike me as being

Re: [Emc-users] Chasing noise

2017-08-10 Thread Les Newell
Hi Gene, I've had a heck of a time with noise when using a 7i90 interface, noise so bad it destroyed several 7i90's by punching thru the 3.3 volt circuitry. That's some serious noise. Do you know where it is coming from? A near field probe is great for finding noise sources. Wrap a dozen tu

Re: [Emc-users] Chasing noise

2017-08-10 Thread Les Newell
My CHNC uses a 7I29 and a single end encoder on the X axis, works fine. All the wiring goes through the same flex guide. Make sure your motor leads are twisted to cut the noise. The motor leads are screened and grounded to the drive. Adding the chokes drastically dropped the radiated noise

Re: [Emc-users] Chasing noise

2017-08-10 Thread Gene Heskett
On Thursday 10 August 2017 12:09:45 Les Newell wrote: > I have been chasing a noise problem on my lathe for some time now. I > am using a 7i29 2kw drive and am getting a lot of noise on the > encoders, even with filtering enabled at a pretty low frequency. I > have tried just about everything I ca

Re: [Emc-users] Chasing noise

2017-08-10 Thread Chris Albertson
I have a spare encoder input on a 7i33 so I moved one of the motor >> encoders to that input. I am getting zero noise on that channel >> >> Has anyone else had noise issues with 7i29 drives? >> >> Les >> > The first thing I think of is that somehow your 7i29 is grounded differently from your 7i33.

Re: [Emc-users] Chasing noise

2017-08-10 Thread Jon Elson
On 08/10/2017 11:09 AM, Les Newell wrote: I have been chasing a noise problem on my lathe for some time now. I am using a 7i29 2kw drive and am getting a lot of noise on the encoders, even with filtering enabled at a pretty low frequency. I have tried just about everything I can think of. I ma

Re: [Emc-users] Chasing noise

2017-08-10 Thread Ed
On 08/10/2017 11:09 AM, Les Newell wrote: I have been chasing a noise problem on my lathe for some time now. I am using a 7i29 2kw drive and am getting a lot of noise on the encoders, even with filtering enabled at a pretty low frequency. I have tried just about everything I can think of. I mad

[Emc-users] Chasing noise

2017-08-10 Thread Les Newell
I have been chasing a noise problem on my lathe for some time now. I am using a 7i29 2kw drive and am getting a lot of noise on the encoders, even with filtering enabled at a pretty low frequency. I have tried just about everything I can think of. I made a simple near-field probe and did a bit