SMC3 Arduino 3DOF 3-Phase AC motor Opto-Coupler shield ...

For interfacing Arduino with VFD's running 3-Phase AC motors ...
Using the SMC3 Arduino 3DOF motor driver Arduino code "In the default Mode 1" .
Opto-Coupler PCB will be like a Dummy PCI card shaped for easy mounting inside a computer ...



All 3 VFDs [analog voltage / direction] and the 3 POT Feedback wirings will be in the PC back side with normal easy to use green terminal connectors ...



Arduino board will be mounted to the PCI shield as a second layer with just the USB cable connected internally to it ...
No additional power socket as it will be fully powered separately via this USB ...

Use an external 12V power supply for the shield power connection not more than 1A is recommended to eliminate EMI motors noise ...
Using the the same computer power supply is still an option for less than 2Hp motors and VFDs cases .


For 6DOF get yourself two of these and you're ready to go ...



The making :
The components side of the opto-coupler will be a regular through hole components but with a surface mounted pads to spare drillings .
The 1:1 printable DIY file for toner transfer PCB process ...
Aduino_SMC3_ArduinoShield.pdf

A great idea by my big friend @cthiggin to do a label sticker for it

Labels for New OPT-PCB - PC - 032717.pdf

A toner transfer with a 3M vinyl sticker will do a perfect job for you ...










Edit: for more information about operational amplifier
http://www.talkingelectronics.com/pay/OP-AMP/OP-AMP-1.html

Thank you for all your advice on VFD's. I want to start a build thread for a 3dof AC motor setup, but I'm not to that point.

Looks great Speedy,

Is there any delay or switching noise (physical not electrical) introduced by the optocouplers?

I could answer that being from analog electronics background for many many years... yes there is responce delay because of the charging time of the RC filter and possible ripples on the analog out signal. Not sure how much as there are no captures of the response of the above circuit in oscilloscope.

Here you can read more why:
http://electronics.stackexchange.co...tant-in-pwm-digital-to-analog-low-pass-filter

Mike

Thanks buddy ...
There is no Relays used here. So, no audible switching noise at all ...

If anyone need to know how a digital circuits can produce a delay in time response ... for all various TTL IC's internal transistors switching it is calculated within the nano second ...
As this is not an INTEL INSIDE GHz to worry about data latching or time taken to travel through the board layers .

Plus, it is not an RC lowpass filter ... The LM324 operational amplifier is used as Integrator and directly driven by PWM digital signal with a basic feedback capacitors that doesn't involve with PWM high frequency side sustaining the analog resolution ... thus converting the PWM duty cycle into an analog signal is extremely high resolution and very responsive .

Simple as that

Edited by Pit, please keep it polite and respectful.

What is the values you used for the RC filter? Perhaps I can calculate the response mathematically

R=resistor (found it on the layout is 10Kohm)
C=capacitor ?

And perhaps the frequency of the PWM signal to do some spectrum analysis. Is it the standard 490hz of arduino?

You do know these values right? I assume it's your design, no?

Ok, using 490hz pwm and C value 10uF:



With above values the response delay is 0.23 sec or 4.3hz period.

You use that for setting the speed of the motor in not wrong right? I guess it's good enough for vfd inverters if you set their ramp settings to 0.5sec.

Mike

A ramp of 0.5secs is really high no? Im running mine at 0.05acl and 0.02 dcl i think

Even though you still believe it is an RC filter , Isn't there any sense of a wrong numbers can be found here ?

Hi guys please stay kindly to each other, I deleted the previous posts, you get another chance

I know - lets look at the relevant specs of the actual OP Amp...- see below. A lot less then 0.23 Seconds .

If you're still unconvinced ... Here is another reference of Operational amplifier and how they may be used .
http://www.electronics-tutorials.ws/opamp/opamp_6.html

Another photos for the opto-coupler with a black mounting brackets to the PC back .



a simulation for the op-amp that is used as integrator ...
http://tinyurl.com/zf9jct9


here is the response time of the PC817 opto-isolator

Hey speedy, great project, but I think the cap values are missing in your pcb layout. Also it would be great if you could post schematics (certainly can be deduced from the board layout, but easier if you have'em...)

Thanks,
Heiko

Hello Heiko ... thanks for pinning that out, they are 1uF/16v ...
Sorry buddy I don't have total schematics for it atm ... as this is the 6th edition of the board right now ... many circuits are added lately and schematics are not updated .

Some more animated explained types of op-amp circuits ...
http://www.talkingelectronics.com/pay/OP-AMP/OP-AMP-1.html

Going further revealing all the secrets and for beating all those BIG expensive interfacing components raping your resources ... A DIY_1HP_VFD is coming out soon .

You can see this circuit has another name of a Voltage Follower with Equal-Gain operation amp. and with a very small smoothing capacitor for the output side .

speedy until now i see this thread, it is grate what you made (i have to confes that i barly undertand the whole thing since electronics is not my natural language)....

how much time and money you have to invest to create this board?

best regards

fer

Nothing complicated here @ferslash I assure you ... this kind of circuits are really simple ... this one is even simpler than having an FM radio signal => demodulated into an audible stereo sound ...

Furthermore everything else is a direct signal shaping and interfacing .

I'll give you a PM for some hints and details .

A great idea by my big friend @cthiggin as he did a label sticker for it

I build one of your pcb for vfd's.
By now, I'm testing and starting to build 3 huge actuators with ballscrews and 2hp motors.
I'm going to share pictures asap.
During test, I see that output is going to max(10 volts) when the feedback pots is on the target.
Maybe the PWM is inverted ?
Is possible the Hi must be Low and Low must be Hi ?