Prototrak Plus Retrofit with Mesa 7i77 & 5i25 cards

Many thanks to all! I am very thankful for your help.
I found the manual to the variable dc power supply (30v5A) so I can describe what is going on with some confidence. If I use the current setting just off the lowest setting, while going up with the voltage setting at 1.5 volt it shows .02 Amp, this is when the servo will start to rotate. At 1.4 shows no amp value until I go up in voltage, to the next value. I have the parts to go back to ptrak if necessary to gain insight. In my own defense I am not "well read" on the finer details of the electrical circuitry as a whole, but I can follow instruction well.

many thanks again!

And the motor is moving slowly? Going to say 2.5 v, and the motor does not speed up? Then it sounds like this may be the enable line and you are seeing drift. From there, with just enough voltage to make the motor move, use that dead, 1 volt or less, battery and touch from ground to the other wire. The motor should speed up. If you reverse the battery the motor should reverse. If you can do this to both axes, you are almost there.

Best, Dan.

lakeweb, Many thanks for all your time!! I can change directions, but cannot change speed. Have not tried the battery, you are describing the wires going from DRV0 take one at a time and go between battery and ground?


Many thanks!

What terminals are you applying your test voltage to?
Way back when in this post
forum.linuxcnc.org/12-milling/30954-retr...-plus?start=40#75164
You said "1.5 v (single battery) the "x" drive it turns slow and apply 2 batteries goes quite a bit quicker."
Do you remember with that test were you connecting the 2 batteries in series (+ to -) or parallel (++ and --)?
Are you testing the same terminals now as you did back then?

And you never did say, what parts did you have to replace, or did you have them repaired?

Many thanks Todd!! The test in question with the battery, I do not recall quite a bit faster, but it has been awhile, the batteries were series. The question about the amp/power supply (I tested prior to this most recent try as the ptrak), this is just used ebay, as is where is. Yes the same terminals.

thanks for all the help!

new2linux wrote: If I use the current setting just off the lowest setting, while going up with the voltage setting at 1.5 volt it shows .02 Amp, this is when the servo will start to rotate. At 1.4 shows no amp value until I go up in voltage, to the next value.

Hmm, this does suggest one possibility we hadn't thought of...:

en.wikipedia.org/wiki/Current_loop

Is it posible that the drives take a 4-20mA signal? (and that the 0.02A on the PSU is really 4mA)