Prototrak Plus Retrofit with Mesa 7i77 & 5i25 cards

Dan, you are a complete and total gentleman to take time to help me out, I cannot miss lead you or others, please reference this link " forum.linuxcnc.org/12-milling/30954-retr...totrak-plus?start=10 " at about 1/2 way down page 3, Todd has started teasing out the old controller and this if you read all the way will tell you how not to plan well or to be careful and I did not get it correct!
My advise to anybody w/o a bunch of control experience or as you were so kindly put it " you are not well practiced with electrical circuits " to make you box with everything needed plugged in ready at one time (making shore you are correct) so if you move it for any reason it stays as a unit.

tommylight, I here what you are saying. Still working the answer.

Many thanks!!

There was a very long thread on this where we were helping this same individual figure out all of this same info. The thread is here:
forum.linuxcnc.org/12-milling/30954-retr...totrak-plus?start=40

Todd Zuercher wrote: There was a very long thread on this where we were helping this same individual figure out all of this same info. The thread is here:
forum.linuxcnc.org/12-milling/30954-retr...totrak-plus?start=40

I just went with the flow.

Ok, I've read most of the previous thread. I see.... I take it this Prototak sysem has rarely been hacked. I could find no conversation on the amp inputs, and I went to the end of the internet. Is it possible they did not use a standard +-10 volts to drive the amp? I can see in the past thread that this was up and running as a Prototak and there was an attempt to get some measurements.

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)