[Wiggles84]

This question is has been bouncing around in my head for a week or two. Was hopping Fastest1 would hear back from leadshine on this but no new info as far as I know.

So..... Why can't the MX3660 be used as a potentiometer for a KBMM-125? The potentiometer that comes with the KBMM-125 supplies on power on its own right? So what is the MX3660 missing that a potentiometer has?

Hoping for some insite on this.

Thanks
Andrew

[Wiggles84]

info from my build thread:

From the reading I gathered:
P1 is the +10VDC
P2 is 0-10V
P3 GND


Went to go give it a whirl... nothing happens. Put the Potentiometer back on the KBMM-125 to test things out.

I get:
P3 ~ P2 0V at WOT (volts go up as I slow it down)
P3 ~ P1 14V Constant

Andrew

[Al_The_Man]

The MX3660 appears to have the analogue output required.
The actual points for the +12v, common and analogue in are common or 0v is either F-v or I2, these are 12v com, the +12v can be picked up either at the (live) end of the max rpm pot or a couple of other places on the board.
If you pick the power up from the P1 and P3 they are 'tailored' by the max and min speed pots.
So if using these, they should be turned to Min resistance.
Al.

[Wiggles84]

Thank you for the response.

Ok, so assume I know nothing about how to do that (because this really isn't a field I know muck about) how would I go about this? Where do I test\tune for the resistance.

Thank you in advance for the wisdom about to be bestowed upon me

Andrew

[Al_The_Man]

If you want to use the analogue out put of the MX3660 with the KB series of analogue (pot) control DC motor controllers.
There are a couple of options as to the +10v supply required by the MX3600.
#1 I would stick to using the actual 0v or common of the KB to connect to EGND on the MX, this would be obtained from either the F- or I2, the F- might be the best choice as it is not usually used, this allows the MIN rpm pot and also I2 to be used if you wish.
For the MX +10v supply, I do not know how critical this is, as the power on the KB is +12v, but if nervous about using +12 instead of +10, you can tailor this by adjusting the MAX rpm pot and use P1 as the +10v source.
The 0v to10v analogue out of the MX goes to P2.
Keep in mind that these are not isolated drives, so there could be a high potential to ground on any part of the KB, this is why the MX analogue output control is normally isolated from the rest of your system.
Al.

[Fastest1]

I talked to John @ Automation Technologies and Chris Li of Leadshine responded via an email.
The MX3660 does not supply 10 volts. It needs an exterior power supply just like everyone else except maybe PMDX. Now the way Al is referring to is different.

Regarding using optical switches for limits and home, the statement was "everyone has used mechanical switches". I am guessing that as long as you connect the ground of the power supply used for your switches with the ground of the MX3660 then it is able to measure the differential

[Al_The_Man]

In the past I have tapped into the +12v on the KB series drives for the analogue supply, the MX shows that normally it could be sourced from the VFD, in this case the source is not evident, so you need to take the steps I mentioned, if using it.
Al.

[Wiggles84]

If you want to use the analogue out put of the MX3660 with the KB series of analogue (pot) control DC motor controllers.
There are a couple of options as to the +10v supply required by the MX3600.
#1 I would stick to using the actual 0v or common of the KB to connect to EGND on the MX, this would be obtained from either the F- or I2, the F- might be the best choice as it is not usually used, this allows the MIN rpm pot and also I2 to be used if you wish.
For the MX +10v supply, I do not know how critical this is, as the power on the KB is +12v, but if nervous about using +12 instead of +10, you can tailor this by adjusting the MAX rpm pot and use P1 as the +10v source.
The 0v to10v analogue out of the MX goes to P2.
Keep in mind that these are not isolated drives, so there could be a high potential to ground on any part of the KB, this is why the MX analogue output control is normally isolated from the rest of your system.
Al.

Thank you breaking this down for me.

But I'm still not getting any power to the MX from the KBMM? And I get no volts when checking across F- and P1 or P2.

I put my multimeter on the Potentiometer set to the 200K ohm and get 5.0 as a reading. So is the KBMM looking for this resistance to enable the power transmission over the connection? I get no ohm's when I test the MX.

Again, thank you for helping me out with this.

Andrew

[Al_The_Man]

You won't get any power from P1 or P2 to F- , especially with with no pot connected (which you do not need) the +10v (or+12v) source will come from either an on board connection or from P3.
So measure from F- to P3.
Al.

[Wiggles84]

You won't get any power from P1 or P2 to F- , especially with with no pot connected (which you do not need) the +10v (or+12v) source will come from either an on board connection or from P3.
So measure from F- to P3.
Al.

Ok now I'm even more confused then when I started!

So here is how I connected the MX to the KBMM:

*EGND to F-
*+10V to P1
*0~10V to P2

Did I misunderstand what you were saying? How am I getting power from the KBMM to the MX to get it back to the KBMM if there is no power between these connections?

Andrew

[Al_The_Man]

Sorry, it looks like I made a slip in post #5, the source of +10/12v is P3 not P1.
I didn't have the schematic in front of me.
Al.

[Fastest1]

He is saying the KBMM should have an onboard 10-12v supply for the MX3660 to use. My Bardac does, unfortunately after talking to them today. My 10v rail is dead. I can operate it with an external power supply though.

[Al_The_Man]

All the KB drives have an on board +12v supply for the low voltage circuitry, it is just knowing where to tap off, the F- or P1 and P3 should supply it, Min and Max are just two pots fed in series with the usual pot, off of each end of the +12 and common, if you do not connect a pot, but a high impedance circuit such as an analogue output such as the MX etc, it virtually ignores the pots and feed common and +12 out of either P1 and P3 or F- and P3.
The F1 or the I2 are both connected to the 12v chassis common.
I know, confusing, I will see if I can post a schematic to clarify it.
Al.

[Wiggles84]

Got it working!!!!:banana:


Here's the connections that made it work

MX~~~~KBMM
EGND~~~P1
0-10V~~ P2
+10V~~~P3


I tried this after I put my multimeter on P1 (red probe) and P3 (black probe) and was getting a (-) voltage reading. With the wires connected to the MX I could get no reading at all before switching P1 and P3.

So I'm guessing that means my power wires to the KBMM from the power strip are connected wrong?


Andrew

[Al_The_Man]

Here is the actual print, as you can see the F- and the I2 is 12v common.
Al.

[Al_The_Man]

Here is the actual print, as you can see the F- and the I2 is 12v common.
Al.

[janekc]

is it working ?
did you switch your power connections?

P1
P2
P3

how do you have it hooked up now ?

this is without the extra power supply ?

[Fastest1]

The KB125 supplies the 12v that the 3660 needs to regulate.

is it working ?
did you switch your power connections?

P1
P2
P3

how do you have it hooked up now ?

this is without the extra power supply ?

[Al_The_Man]

If you do use the P1 & P3 as the 0 +12v take off, the MIN & MAX pots should be turned to their minimum preferably.
MAX to +12v and P1 to 0v.
Al.

[Wiggles84]

is it working ?
did you switch your power connections?

P1
P2
P3

how do you have it hooked up now ?

this is without the extra power supply ?

Yes it is working
Not sure what you mean by "Switch your power connections"

I will have to confirm the wire placement in the morning for P1 P2 P3

Yes this is 100% powered off of the Kbmm-125 P1 P2 P3 connections.

I had went down to play with my electronics and make a quick video to show you it works, but started to try and figure out other issues I'm have and didn't get to it. One issue I am having at the moment is that mach and the kbmm-125 do not like to be in sink on the speed. I have it set for 7000 max RPM and 0 as low. It does not it like to follow the S commands. I put in S7000 and get 7000 at the motor. But as I scale it back the speeds are different. S1000 gets me like 136 RPM and anything lower get no movement at all.

Just more to figure out I guess?

Andrew