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Re: 240volt motors and SSR issues

Posted: Thu Feb 15, 2024 12:58 am
by NZ Mike
My running theory was to run 3 of the kemo modules, each running 2 motors. Which should see them kept at 11A max per module. All just ideas at this stage and i am glad for the time you have taken replying so far.

I assume by small circuitboard to attach to the ssr from Farnell/element14, you are talking about a phase angle control board? Forgive the questions, this is all learning for me and i am trying to absorb it all.

I found this while browsing today, aside from the amp rating being too low, would something like this work?
https://nz.rs-online.com/web/p/thyristors/2329353?gb=s

The help is much appreciated.

Re: 240volt motors and SSR issues

Posted: Fri Feb 16, 2024 5:26 pm
by Tony
That last module has one serious problem, it uses a "triac" as the main power controlling device, and not back to back SCRs.

The difference is that triacs can be very temperamental and can become erratic in the presence of electrical noise. If you read through the data sheet for that module, it says suitable for resistive and SOME types of inductive load. I am pretty sure, sparky old brush motors are going to cause a lot of grief.

Good random fire power modules use back to back SCRs and are extremely tolerant of nasty sparky loads.
There really are no short cuts to any of this.

Still think you are going to have to grit your teeth, hold your nose, and cough up the outrageous postage and import tax and get something from Bruce.

In pretty much the same situation here, the US/Aussie exchange rate is not particularly good right now either.

Re: 240volt motors and SSR issues

Posted: Mon Jul 08, 2024 1:32 am
by Bearwen
Sorry I have been playing with the flowbench lol and life in general has just gotten in the way.

Any how the SSR I ordered was a Random fire type I don't recall which one I bought but make sure its a random fire as per the manual of the controller.


I built my own electronic sensor system and wrote the software to control it in Python and it all runs on a raspberry pi.
That's also part of why I never replied as once the bench worked I had to learn to code enough to write the software for my bench and sensors.

No I will not share it or sell it honestly if you don't work in electronics ( like I do ) or have friends who can help you with coding ( like I do ) you should buy bruces setup.

Honestly with the time and what not involved it would have been cheaper to buy bruces setup.

Only reason I didn't was because I wanted to be able to modify and adapt my setup and I have the skills and friends to make it happen.

Re: 240volt motors and SSR issues

Posted: Mon Jul 08, 2024 6:17 pm
by Tony
Great stuff !!!

Writing a phase control program makes for an especially interesting software writing project, if learning to code is also a secondary objective of building the bench.

For most of us though, just getting one of those small low cost control circuit boards from Bruce is a much cheaper, faster, and simpler solution.
But there is also a great deal of extra satisfaction of doing something yourself, and picking up new skills in the process.