any electronic engineers based in australia

dendad

Joined Feb 20, 2016
3,591
It really does not matter where folks are if you just want advice.
What sort of help do you need?
And where in Oz are you?
I am a couple of hours North of Melbourne, although I do not have an official "Engineering" ticket. Just 45+ years of experience.
 

Thread Starter

fulsik

Joined Dec 10, 2018
5
thanks..im working on a magnetic pulse motor with 8 coils and 8 magnets, these need to be be pulsed when magnet and coil align , im using and arduino with solid relay but would like to have speed control by dial that can configure bandwidth as well....thanks for the support
 

LesJones

Joined Jan 8, 2017
2,687
Are you using 8 outputs on the Arduino each driving one of the 8 coils via 8 solid state relays ? You could control the speed of the pulses by inputting a voltage from a potentiometer to an ADC input on the Arduino. I don't understand what you mean by "bandwidth" in this context. Can you explain ?

Les.
 

Thread Starter

fulsik

Joined Dec 10, 2018
5
hi..no just one relay that pulses when arduino triggers the relay, i need a 2 milisecond bandwidth for the magnets and coils , this is where its acheiving best results...cheers
 

dendad

Joined Feb 20, 2016
3,591
A bit of a diagram may help.
Usually it works better with offset coils so you can pulse some coils then the others to control the direction of the motor.
 

MisterBill2

Joined Jan 23, 2018
6,718
I have already come across postings from many different parts of the world. This is an incredibly diverse site.
And the only challenge is that distance makes visits challenging.
 

LesJones

Joined Jan 8, 2017
2,687
You seem to be using the word bandwidth when you mean pulse width. I agree with dendad's comments. I cant see how it can work pulsing all the coils at one time.

Les.
 

dendad

Joined Feb 20, 2016
3,591
You need to post a diagram of your setup as I have doubts it will work. More details are needed so we can help you.
 

MisterBill2

Joined Jan 23, 2018
6,718
It is impossible to get a 2 millisecond pulse from most mechanical relays, the very best will be at least 20 milliseconds, and that not from a relay able to deliver much current. Solid state relays may be able to deliver shorter pulses, but probably just using a switching transistor would be more cost effective. And this application sounds very familiar, at least to me. One challenge that is unavoidable with magnetic coils is that the inductance tends to limit the current rate of increase, so that getting a fast rise of current through a coil takes a more complex circuit than if it were just a resistance. Driver circuits for fast stepper motors are a good example of how some have been able to make it happen. So there are ways to make it happen, but they are not really simple.
 

MisterBill2

Joined Jan 23, 2018
6,718
I am begining to think this could be an over unity project the way that information is being withheld.

Les.
My thinking also. But possibly something else. Rotating through 8 coils in 16 milliseconds would deliver close to 60Hz, 3600RPM. so it could be an experiment to produce a monopolar synchronous motor device. But there may be a few technical issues that I missed along the way.
 

Thread Starter

fulsik

Joined Dec 10, 2018
5
FAIRLY CLOSE GEUSS , IM USING A MAGNETIC PULSE MOTOR TO POWER GENERATOR SO YOU WERE ON THE RIGHT TRACK...HOWEVER IM INTERESTED IN MISTERBILLS RESPONSE RE DIFFICULTY IN ACHEIVING PULSEWIDTH WITH RELAYS AND I THINK HES RIGHT EVEN WITH THE ARDUINO PULSING THE SOLID STATE RELAY IM STILL HAVING DIFFICULTY IN ACHEIVING THIS TARGET, I WILL TAKE HIS ADVICE AND TRY SWITCHING TRANSISTORS...THANX FOR THE ADVICE GUYS
 

MisterBill2

Joined Jan 23, 2018
6,718
FAIRLY CLOSE GEUSS , IM USING A MAGNETIC PULSE MOTOR TO POWER GENERATOR SO YOU WERE ON THE RIGHT TRACK...HOWEVER IM INTERESTED IN MISTERBILLS RESPONSE RE DIFFICULTY IN ACHEIVING PULSEWIDTH WITH RELAYS AND I THINK HES RIGHT EVEN WITH THE ARDUINO PULSING THE SOLID STATE RELAY IM STILL HAVING DIFFICULTY IN ACHEIVING THIS TARGET, I WILL TAKE HIS ADVICE AND TRY SWITCHING TRANSISTORS...THANX FOR THE ADVICE GUYS
In addition, study the circuits for things like stepper motors and horizontal deflection circuits, where fast pulses had to be driven through inductive loads. Stepper motors especially, since their function is sort of like the system you are building. One other consideration is to think, do you really need a square wave? Non-square waves are easier to create.
 

BR-549

Joined Sep 22, 2013
4,938
Aussies live and visit here all the time.

I was watching a show on tv about Australian truckers. What you fellers need down there is an active A.I. suspension. And free dental. Those roads will shake your teeth out.

Hundreds of washboard miles. You need an embedded, inverted washboard suspension. Especially on the triples.
 
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