MesaCT problems with 7i96 pwm spindle

Yeah, sorry, I copied them from a 7I96S halshow and forgot to delete the "s"

thanks jt, that was making me go bonkers trying track that one down. found that in one of my other machines configs and it worked!

as for the pwm voltages, i just got through checking everything and i shouldn’t have any load on the pwm at all. the 7i96 is powered with a dedicated 5v 0.55a psu. i adjusted the pot to 5.42v(i dare not go any more) and i get 5.31v between +5 and gnd and at 24k rpm which is max, i get same between gnd and pwm- when i have the cable to the vfd box disconnected. when i connect the cable it drops to 4.86v. is the converter actually pulling a load?  i can get close to 10v if i boost the input voltage to 14v which is within the range of the board, but is that just a hack or will that work?  or is the psu for the mesa board under powered? i saw that in a post that 250ma was enough without any loads. 

     

250 mA is really marginal...
 

PCW wrote:

250 mA is really marginal...

so what would you recommend?  am i under powering it? 

thanks tom for the words of wisdom as always. i have some new modules coming this afternoon and i will give those a go. ill also dig around and see if i have another 5v din psu floating around. i thought i had a 2a one somewhere here

Actually, the PWM --> analog circuit normally should not
care what the PWM input signal level is as long as it's enough
to drive the input circuit. That is, it should work identically
with a 4V signal as a 5V signal.

that is what i thought. it should just be a proportional voltage coming out, but there must be a small load on it because my pw
voltage drops about 0.5v when i plug it in and tye only way i can get 10v or close is to increase the input voltage to the module to 14v.

these are the new ones i have coming.
a.co/d/5rSxmMy
which is similar to tye board i have now.

i could just use rs485 to control the spindle, but this is a big machine and at least for now i use the same computer to control 3 machines and i dont want to have 2 cables running across the floor. i trip over one often enough, so i need to try and get this pwm running

Does that potentiometer on the PWM --> Analog module adjust the scale?

it does adjust the output voltage a bit, but not the scale i dont think.

so here are some numbers when its working

mesa - 5.2v
pwm module - 12.1v in
m3 s12000 (min) - 2.34v in (2.53 unplugged) 4.92v out
m3 s24000 (max) 4.65/5.07(u) 8.62 out

if i step up the input voltage to 14.2v i get 9.77@24k and 5.24@12k

if i adjust the pot on it i can get 10v but only at 14v. i max out at 8.65 @12v. but when i get 10v, im at 5.78 on the low end which i suppose wouldnt be all that bad with an air cooled spindle vs going too slow