Recommend me a servo amplifier / driver / h-bridge
10 Oct 2017 22:26 #100169
by andypugh
Replied by andypugh on topic Recommend me a servo amplifier / driver / h-bridge
Do you need to reverse the spindle? If not, then you might be OK.
The cheapest extra Mesa card to do the job is store.mesanet.com/index.php?route=produc...83_88&product_id=122 (which would connect via the smart-serial port on the 7i76). I did read the part where you said you didn't want to do that.
There may be some useful ideas here: forum.allaboutcircuits.com/threads/diffe...to-10v-output.62406/
The simple solution might be a DPCO relay controlled by the 7i76 REV output. It seems inelegant, but ought to work, I think. Though I would prefer something solid-state.
i55.tinypic.com/29xzpd3.png
1 - 5V
4 - Drive 0V
6 - 7i76 OUT+
8 - 7i76 OUT-
9 - 7i76 OUT-
11 - 7i76 OUT+
13 - Drive +/- 10V
16 - 7i76 DIR+
(And 7i76 DIR- to 5V GND)
The cheapest extra Mesa card to do the job is store.mesanet.com/index.php?route=produc...83_88&product_id=122 (which would connect via the smart-serial port on the 7i76). I did read the part where you said you didn't want to do that.
There may be some useful ideas here: forum.allaboutcircuits.com/threads/diffe...to-10v-output.62406/
The simple solution might be a DPCO relay controlled by the 7i76 REV output. It seems inelegant, but ought to work, I think. Though I would prefer something solid-state.
i55.tinypic.com/29xzpd3.png
1 - 5V
4 - Drive 0V
6 - 7i76 OUT+
8 - 7i76 OUT-
9 - 7i76 OUT-
11 - 7i76 OUT+
13 - Drive +/- 10V
16 - 7i76 DIR+
(And 7i76 DIR- to 5V GND)
Please Log in or Create an account to join the conversation.
15 Oct 2017 10:48 #100382
by pippin88
Replied by pippin88 on topic Recommend me a servo amplifier / driver / h-bridge
Andy,
Thanks, I got it working (sort of - need to sort reverse speed).
Omron G6S-2F 12V relay - DPDT relay
Wiring:
SPINDIR+ = 12V
SPINDIR- = Relay coil +
Flyback diode across relay coil
One pole of relay has:
NC - SPINDLEOUT
NO - Ground
Other pole has
NC - Ground
NO - SPINDLEOUT
Relay outputs are connected to Copley 422 amplifier REF+ and REF-
Problem at the moment is that forward works at the correct speed, but reverse does not get to full speed. I'm sure this is a software problem, as when I invert the SPINDIR in HAL, reverse works at full speed and forward does not get to full speed, therefore it isn't a motor / amplifier problem.
Thanks, I got it working (sort of - need to sort reverse speed).
Omron G6S-2F 12V relay - DPDT relay
Wiring:
SPINDIR+ = 12V
SPINDIR- = Relay coil +
Flyback diode across relay coil
One pole of relay has:
NC - SPINDLEOUT
NO - Ground
Other pole has
NC - Ground
NO - SPINDLEOUT
Relay outputs are connected to Copley 422 amplifier REF+ and REF-
Problem at the moment is that forward works at the correct speed, but reverse does not get to full speed. I'm sure this is a software problem, as when I invert the SPINDIR in HAL, reverse works at full speed and forward does not get to full speed, therefore it isn't a motor / amplifier problem.
Please Log in or Create an account to join the conversation.
15 Oct 2017 14:49 #100391
by PCW
Replied by PCW on topic Recommend me a servo amplifier / driver / h-bridge
Make sure you use the absolute spindle speed command (negative numbers for spinout will cause problems)
Please Log in or Create an account to join the conversation.
16 Oct 2017 05:15 #100424
by pippin88
Replied by pippin88 on topic Recommend me a servo amplifier / driver / h-bridge
I am using the absolute speed command.
I have tracked the problem further, it appears to be due to single ended signal into the differential input on the drive.
Measured at the servo amplifier input:
REF+ grounded, and REF- supplied 10V results in full speed
REF+ supplied 10V, and REF- grounded results in about 800rpm which then drops to about 700rpm.
I have tracked the problem further, it appears to be due to single ended signal into the differential input on the drive.
Measured at the servo amplifier input:
REF+ grounded, and REF- supplied 10V results in full speed
REF+ supplied 10V, and REF- grounded results in about 800rpm which then drops to about 700rpm.
Please Log in or Create an account to join the conversation.
Time to create page: 0.520 seconds