Hi All,
Have said all here and on USB CNC forum, these PWM chips are from Toshiba and noting wrong with the chip
design it's self and at the time. Toshiba has a replacement for TB6560 PWM chip with better motor handling
specs. as you need not worry about powering 5v logic circuit.
But all said, the Chinese implementors of various TB6560 stepper controllers must have blindly copied, & further
corrupted the original circuit from a Japanese source if could remember!
Any one trying to recover/correct these errors MUST read Toshiba's Technical manual and TB6560 application
note.
For example, on some Chinese TB6560 controllers power save mode is implemented as recommend by Toshiba
see page 10, paragraph 5 of TB6560AHQ/AFG technical manual. If you are fortunate and DIP switch is
implemented then you may tune individual settings for
1. Excitation Mode on Page 9 paragraph 1.
2. Torque Settings on Page 10 paragraph 5.
3. Decay Mode Settings on Page 9 paragraph 4.
Finally see CR oscillation tunning on Page 10 paragraph 8.
Every stepper motor has to be tuned to run smoothly, thats what Decay Mode Settings is for!
See Toshiba Application Note [TB6560AHQ_applnote_en.pdf]. On page 6, paragraph 5 its all there.
One caution I will add is that, pay attention to Z axis motor setting as gravity pulls on what ever spindle you've
got in there, else you might loose steps as spindle assembly is in free fall due gravity when in stepper motion!
I just don't get it. What the heck are the opto-isolators doing in there. Should you closely study these Chinese
controllers on the market, circuit layout just defeats the purpose of an opto-isolator! this brings to mind a
Copy-And-Paste syndrome.
Can someone enlighten me on worse case scenario should Toshiba chip goes up in puff of smoke/fire to
your PC parallel port?
These Chinese controllers are comparably affordable but be prepared to fix these sloppy design at your
own cost if you know how, else go get yourself a Rolls-Royce stepper drive and have some peace of mind.
By the way am a proud owner of one of these Chinese controllers but I did my way
Cheers to you all.