- This topic has 7 replies, 6 voices, and was last updated 20 years, 10 months ago by
.
-
Posts
-
Anybody know how to (re) program the dsp on the daughter board? I want to use the smartdrive motor as a giant stepper motor.
I assume the connection from key pad to motor controller board is basically a serial port connection.
Thanks
AlexSilicon Chip magazine should be able to assist you based on they have in their Dec04 to Mar05 publications used a F&P motor as a Wind turbine and welcome enquiries of this nature.
alexa wrote:Silicon Chip magazine should be able to assist you based on they have in their Dec04 to Mar05 publications used a F&P motor as a Wind turbine and welcome enquiries of this nature.
Have already used them as wind and hydro generators, TIP put a bridge rectifier on each pole and then combine them in series or paralle to match the working speed!
What I want is to use the power and control circuitry to control the motor in other environments
Alex
Re: Fisher Paykel smartdrive motor controller
Exploratory science. Given our very limited experience of these appliances in the UK and Alexa’s comments (he is our only regular OZ Trade poster) you may have to solve this yourself. Wash action is initiated by the completion of the water level control circuit, spin sequences by breaking it; so you’re looking at figuring out the switching circuit on the board to allow direct motor control.
Beyond that, I suspect that we can’t really help you – although I would be fascinated to know how you get on.
Good luck,
Penguin45.Re: Fisher Paykel smartdrive motor controller
spin sequences by breaking it; so you’re looking at figuring out the switching circuit on the board to allow direct motor control.
Beyond that, I suspect that we can’t really help you – although I would be fascinated to know how you get on.
Good luck,
Penguin45.Thanks
Effectively the motor is a three phase (permanent magnet) motor powered by a variable frequency inverter that is controlled by a pre programed micro computer (or dsp) with feedback from hall sensors tweaking the pulse width modulation.
That is all fairly simple, however F&P are paranoid about industrial espionage and the actual specs and pinouts of the controller chip is not available.
With the right info it should be posible to up load any step and direction info into the dsp’s flash memory and use the motor to run any cnc type machine.
Get my drift?
AlexDoesn’t anyone else use the same controller? I’m going to guess it’d be easier to seperate the programming side of things from the inverter and input your own PWM based on whatever sensors you require. R/C servos have a PWM drive, maybe the format is similar? Best get the ‘scope out.
I’d say tho that you’re unlikely to get good step control out of a 3-ph machine, especially one that was designed for continuous/ hight speed operation.
David
dpm wrote:Doesn’t anyone else use the same controller?
I’d say tho that you’re unlikely to get good step control out of a 3-ph machine, especially one that was designed for continuous/ hight speed operation.David
There are no useful markings on the chip, but my guess is that it could be texas instruments. It could be totally custom built.
1000rpm with 14 pulses per rev, a 12MHz DSP could have a cup of tea between each pulse. I think the controller could even micro step it.
Somebody out there must know how to reprogram it
Alex
Re: Fisher Paykel smartdrive motor controller
If there is no device number on the DSP / MCU chip then it is probably a specialised device, although why is another question, as these programmable driver IC’s are readily available from many of the manufacturers. In fact it is the development of these driver IC’s that has made the use of this type of motor economically feasable in domestic appliances to achive complex electronic commutation at a realistic cost.
There is no reason why a control device from an other manufacturer (with full info available on interfacing and programming) could not be used with the existing inverter, as motor control is achieved through six outputs to drive the inverter stage, three inputs from the hall effect sensors and possibly a PWM output to a power factor correction stage, although this may not be implemented on small motor inverter chips.
Programming probably involves flashing the required sequence and timing data into an eeprom.
Whether it is possible to achieve step control of these motors using these driver IC’s is another matter?
Another possibility which I have been contemplating is control using a PC’s parallel port, some circuitry may be needed to adjust the levels to that required by the inverter inputs but should’nt be too difficult (might be safer to use an opto isolator stage). Then it is just a matter of writing the software to read the hall sensors for positional data and and send pulses of the required timing, duration and sequence to each of the invertor inputs. This would probably have to be done using for eg. C+ as I don’t think that Visual basic has easy access to the parallel port.
Control as a stepper motor could be easily achieved using this method.
Just for those who might not know – the inverter stage usually comprises three sets of power transistors (either bi-polar or MOSFET’s) each of which are configured as two devices wired in series. This configuration allows each pair to either source or sink current and allow the current flow through the coil to be reversed. The coils may be either star or delta wired. So a rotating magnetic field is achieved by turning on each of the power transistors in the correct sequence.
The pulse sequence and timing can easily be obtained from many of the data sheets for these devices.
Andy
- You must be logged in to reply to this topic.