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Last year we had a very hot Summer and Autumn so had a presumption that we should need a very big fan in our shed to get our job easier this year.
This motivation gave me a way to build a single phase Variable Frequency Drive for a bigger fan motor!
Fortunately or unfortunately we have cool Summer now, so not yet get a new big fan yet, nor have a chance to run this VFD...
Attachment 35988
Attachment 35989
Attachment 35992
Inside: Triangle and rectangle generators are analogue unit.
Started from these;
Attachment 35995
Attachment 35996
Making shifts to the frequency is to be done with a couple of white dials, an obsolete analogue way.
Attachment 35997
Attachment 35998
Chy
But on the way of assembling I found this handmade case was a tad small:headscratch:, so added some more rooms ;
Attachment 36001
Main power board with magnetic contactor and a transformer;
Attachment 36002
Placed a noise filter right after the main contactor;
Attachment 36003
Temperature sensors are placed onto five different part,
1: Bridge diode (50A),
2: Short cut unit,
3: Isolated Gate Bipolar Transistor unit,
4: High speed diodes for return current re-circulation unit,
5: Double 2mH filter coils right before the output terminal;
Attachment 36004
Output frequency monitor;
Attachment 36005
Output current monitor, and its detector (HAS-50);
Attachment 36006
Attachment 36007
Chy
Schematic for power units is;
Attachment 36008
Chy
please note there may be a wrong design in above drawing.
A couple of logic units of this type is known as noise-fragile to electro-magnetic noises. This part was one of the complexities to me.
Attachment 36009
Units in the right half (marked yellow) are electrically shielded with copper plate around them, they are a triangle wave generator and a wave form comparator, and a sine wave generator.
These in the left half are also shielded with so called shield wire (black wires), they make up a Pulse Width Modulation logic unit.
Chy
That's great. Well done.
Why three Arduinos?
Good morning Nova, Why? ,,, only because I did not know other ways, lol. Do you make them in one Uno?
Chy
p.s. Glad to know you are a specialist of robotics, Nova!
The logic unit needs a delay-time-unit for one of the safety purposes;
Attachment 36010
This unit is not yet given the noise shield.
The delays are confirmed with oscilloscope views;
Attachment 36011
Attachment 36012
Chy
Does the breadboard not contribute to rf noise ?Once the design goes to PCB there should not be so much interference.
Thanks trigger, will keep your words in mind.
Chy
Schematic after the power unit is as follows;
Attachment 36013
showing a LT-spice view, where the triangle, sine wave generators are replaced with a simple built-in parts of LT-spice.
Output wave in LT-spice simulation (red lines), and a couple of real ones (oscilloscope views) here;
Attachment 36014
Attachment 36015
Chy
IGBTs, High Speed Diodes, and Output Filter Coils are placed in the metal shield room;
Attachment 36016
Attachment 36017
Chy
For an observation and study use, I added several kinds of carrier frequencies from 2kHz to 14.5kHz;
Attachment 36018
Chy
Trigger, I tried to recall my memory and some data on this, and here found a pic showing comparison between the two, before shield and after shield.Quote:
Originally Posted by trigger
Either case bread boards were already replaced with universal boards.
Attachment 36019
Although the carrier wave was not very stable, I know the reason that the center common level was a tad off-set. the thicknesses of the sine waves tell the shield shows effect on it.
This tell us that even PCB board wants some means for cutting noise.
Chy
Shoot me your code. I can have a look at it if you want. Are you bit-banging the Arduino functions? Interrupts and PWM outputs are very, very nice when you get them set up. If you swapped the three Arduino Unos out for one Arduino Due you can definitely monitor current, frequency and temperature with a single board, but you could probably also generate your sine waves. Arduino Dues are very fast. There are also lots of other (and much faster) boards to choose from as well. If you're having frequency and noise issues driving it directly from a microcontroller might solve some oscillator problems.Quote:
Originally Posted by chy_farm
Again, awesome project and great work.
Nova, thank you very much for your kindness.Quote:
Originally Posted by nova_robotics
This information is very big for me, for years I have been learning C, but not yet graduate from a first grade though, lol.
When I got to know Arduino, was a bit disappointed that it uses C++, which uses 'Class', this makes me mixed up and still I am loosing my way to restart learning.
So this offer is very great to me! Perhaps you make me stand again and start again Nova. Will try posting the code and ask you for your information.
Many thanks!!
Chy
Hi Chy-Farm, Thanx for this extensive communication. Now I am curious about the IGBT circuit. And is 100V the standard grid voltage in Japan?
regards, Carnel
Hi Carnel, yes! It's as low as 100V, lol. This makes us sometimes frustrated though.Quote:
Originally Posted by Carnel
Chy
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Thanks chy_farm! We've added your Factory Fan VFD to our Electronics category,
as well as to your builder page: chy_farm's Homemade Tools. Your receipt:
<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/homemade-factory-fan-vfd"> <img src="/uploads/234794/homemade-factory-fan-vfd.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/homemade-factory-fan-vfd">Factory Fan VFD</a> <span> by <a href="https://www.homemadetools.net/builder/chy_farm">chy_farm</a></span> </div> <div class="tags">tags: <a href='https://www.homemadetools.net/tag/fan'>fan</a>, <a href='https://www.homemadetools.net/tag/controller'>controller</a> </div> </div> </div> </div>
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Just wanted to say as others above : Great work !
Yes, for the command and monitor part, I think you can improve things, but this is really details compared to the impressive work.
I am especially impressed by the power unit part, this is something that keeps to intimidate me.
I'm curious if you have made an account of the total cost of your solution ?
Thanks Christophe,Quote:
Originally Posted by Christophe Mineau
Well,,, my answer should be NO,
this is a sort of art work to me, so I do not mind too much about the balance sheet, in other words I get something 'Price Less' out of it, lol.
Interesting view on scope ,my comment was due to my own small project building a tracer ,had issues with noise on the scope till I changed the build over to PCB,and proper BNC plugs.
I am certainly not up to your level of tinkering but enjoy the improvement to the welder and the current project keep em coming
Thanks Trigger,Quote:
Originally Posted by trigger
Yes I can get what you have on your oscilloscope. Noises on oscilloscopes are real issue to us. Several years ago I was very fortunate to bump into a guy who wanted to sell an active probe made by Tektronix, was almost new!
This active probe solved 1/3 of my issues given by this kind of noises.
Thanks again, am glad you like this.
Chy
Oh you don't have to. You can use plain dirty old C to program an Arduino. You don't need to use classes at all.Quote:
Originally Posted by chy_farm
Good morning Nova, thanks. This makes me feel a lot more easy about C.Quote:
Originally Posted by nova_robotics
Chy
Hi Trigger, as far the “noiseless” active prove for an oscilloscope, today I shot a pic of it. Posting it here for you.Quote:
Originally Posted by trigger
Attachment 36097
Hope this will help you a bit.
Ooh big boy toys,I am totally out your league I play with PC scope ,and mostly blow up stuff I try to repair.
