Designing my own TB6560 AHQ driver boards...

After some great discussion over which board to buy, my conclusion has been to make my own driver boards.

Keeping cost as low as possible is my main aim, so I will reuse and recycle wherever possible.

Planning on one board per stepper motor (ease of repair) but sharing a common heatsink and power supply. I'll also be designing a spindle speed controller too. The whole assembly will fit inside my computer case for neatness, steppers, spindle drive, and power will connect at the rear of the PC.

I've bought 4x TB6560AHQ IC's off Ebay for just less than £10.00.

I have in my shed a nice selection of electronic components, and some bare PCB, which will save some more cost.

I'm designing the PCB using EAGLE PCB software, again made freely available by the nice Linux community.

A friend has a desktop CNC mill, and is willing to machine the boards for me, for a pint of beer!

Cheers, Scott

First Question:

Opto Isolators / Opto Couplers.

All optos have some time lag with switching on and off, some are faster than others.

I'm trying to select the best ones for the job of sitting between my drive boards and the Parallel Port.

Has anyone had any success / failure stories on which to use, or which speeds to aim for?

Cheers, Scott

ScottBouch wrote:

First Question:

Opto Isolators / Opto Couplers.

All optos have some time lag with switching on and off, some are faster than others.

I'm trying to select the best ones for the job of sitting between my drive boards and the Parallel Port.

Has anyone had any success / failure stories on which to use, or which speeds to aim for?

Cheers, Scott

I have used these:
HCPL-0201-500E fast, 20 V, SMT 516-1704-5
HCPL-063L-500E fast, 3.3V SMT

These are all surface mount, but there probably are DIP versions available. They are
both buffered, so they have a sense amp in them which improves speed.

Jon

Hi Jon,

Thanks for the useful insight, I'll look into them!

I imagine the buffer gives a sharper transient..

Thank you again, Scott

Hi Jon,

I've just looked up the datasheets for those IC's, and they look perfect for the job! Thank you for the heads up!

Cheers, Scott

ScottBouch wrote:

Hi Jon,

Thanks for the useful insight, I'll look into them!

I imagine the buffer gives a sharper transient..

Thank you again, Scott

Yes, it is also supposed to reduce pulse width distortion and allow the
LED to be operated at lower current. I normally run my LEDs at
about 5-6 mA and get rapid on/off of the output. I've been using
a variety of devices from the same product line for over 5 years
in my PWM servo amps with good results. I went from a 12V
logic supply and CD4000 chips to 5 V finally down to 3.3 V
in the latest model.

Oh, that reminds me, you need a good decoupling cap on the
logic supply for these or the output can glitch. That can cause
feedback, where the switching of the power transistors gets
back into the output of the optos and causes misbehavior
of the drive.

Jon

I note the datasheet shows yhe supply rails on the PCB being identical to each other, but one on the top, and one on the bottom, is this a rule you've followed?

This layout reminds me of balanced microphone circuits.

Cheers, Scott

Can a PC's parallel port drive a 6mA output? Should I use an op-amp buffer or transistor to drive the opto's LED?

And likewise, I must also consider the capabilities of the feedback outputs from the TB6560AHQ.

Don't want to be causing any damage...

Cheers, Scott.

Thank you,

I've been trying to get some specs from Dell on my parallel port's capabilities.

Avoiding additional components will help to keep lags down, since I'm looking at the fast opto's that Jon recommended.

Looking forward to using the Parallel port test program and experimenting!

Thanks, Scott.