Speed Controller Wiring - check me

[TravisR100]

Can someone take a look at my diagram and let me know if it looks OK? I'm trying to wire up a KB Electronics KBMG-212D speed controller to a CNC4PC C23 BOB. I've got it wired to switch between local and computer control. Please see attached diagram. This will allow me to do forward and reverse with the pot. Not sure how to get forward and reverse through the C23 however. The drive requires +10 to -10v for forward and reverse and the C23 will only output 0 to +10v.

[Al_The_Man]

You can also connect the outer ends of the pot to +15 & -15 (no switch) and just switch the slider in when in local mode, pot centre would be zero speed.
If the BOB is 0-10v, then you are out of luck with reverse.
Switching the armature would do it, but defeat the object of reversable drive.
Al.

[TravisR100]

Al, does my wiring look OK otherwise? I thought maybe I could use a dual output DC-DC converter to get 0 to -10v from the BOB and drive it with a relay to switch between the outputs. But all the dual output converters seem to output 5v or 12v, not 10. I suppose a properly sized resistor could get it down to 10 from 12 but at that point it seems like an awful lot of electronics.

I was also told by CNC4PC that instead of using the isolated DC converter to get the 12v to the board that I could simply take the voltage from the drive's COM and +15 terminals. It only requires 10ma. Any thoughts on that?

The 3PDT switch that I show on the diagram was intended to be just that, a switch. But since I'm thinking of using a 2 position Eaton selector switch it would seem cheaper to just use a single contact block on the switch to drive a 3PDT relay. Those contact blocks get expensive and I' require 3 of them. Would also be less wiring between the switch and the backplate of the cabinet that way.

[Al_The_Man]

The spec's of the KB show either ±10vdc or ±15vdc analogue control.
I would think a relay would be the best way to go, If the +15v supply will support the BOB then I would use it.
Switch the relay coil from another source, however.
BTW, I have noticed that some of the larger KB units have a control isolation transformer and are not referenced to the AC switching SCR's. like the smaller models are.
Al.

[TravisR100]

This drive is odd. If you are using the pot you are supposed to set a particular jumper for 15v. If you're using the 0-10v signal you're supposed to set this jumper to 10v. I called them to explain I wanted to switch between both. They said to set the jumper to the 10v position and to include the 2.2K resistor which you see in my diagram. According to Arturo with CNC4PC the BOB will support the 10v reference signal. I may try that before going with the DC converter.

This particular drive has the option for an isolator.

I was going to switch the relay coil with the mains using this relay:

https://www.alliedelec.com/Search/Pr...4AC110%2f120(S)

For anyone interested in this drive, manual can be found at:

http://www.kbelectronics.com/manuals/kbmg_manual.pdf