The can of worms is back! (blower motor speed regulation)

Now that I got you to click on this... Watch this and please tell me WTF is going on.
Thanks!



I did find this online. Maybe my learning was through osmosis while sleeping on my books.
http://www.factsfacts.com/MyHomeRepair/DimmerSwitch.htm

 

That is a nice camera.
I have considered one, but don't have the dolaros to spend on it right now.
The wife wanted a new kitchen table and chairs (now), and those things are not cheap so that was this month's investment.

My Canon EOS Rebel takes a decent video, but I think it has an automatic cutoff after 2 minutes or so, and it is very bulky; not to mention the fact that if I break it during a melt, I don't have a camera to use for work photos anymore.

Anyone have a recommendation on a good cheap video camera; cheaper than a gopro?

You should try the voltmeter plugged in with the fan, into the same extension cord on the load side of the dimmer switch.
I don't think the small voltmeter is loading the dimmer enough to register anything when the knob is turned.

They would not put frequency modulation (FM) in a dimmer switch (I don't think).
It has to be clipping the waveform, ie: reducing the voltage.

That video makes me thirsty.

 

I'll try it and report back... The gopro 6 is 399 at the moment and you can pick up the 5 for 299. I still havent modified the case to open up the holes for the microphone. They suffer a bit from sound quality as I can hear it in this video.

 

Pat you were right.. With the 2buck volt meter in the plug and spinning the fan. It DID read a change in voltage. At full spin, it was 108 volts and then would lower with the fan as I dialed down the dimmer switch. Now I'm even more confused.

 

The small meter may not be reading true RMS I suspect, and its accuracy is probably low.

The dimmer is clipping the voltage.

 

SO in that case, we are back to square one. While it works, it's still not a good idea to under volt motors. Off to the back of the class I go again.
Not a total waste of an evening. I discovered the sound sucks because the case that holds the gopro6 completely covers 1 of the microphone holes on the side and partially obscures the top microphone hole. (it has 3 microphone holes)

How the hell these clowns don't address this issue with a simple mold change is beyond me. 1/8" drill bit and some careful drilling makes it now sound so much better.

 

I specify VFD's for a lot of motors, and they all reduce the voltage to the motor (to the best of my knowledge).
I do spec VFD-rated motors, but that is due to the solid state device spiking the windings, so a high insulating value is needed.

I have not used a lot of dimmer switches on 120 volt motors other than shade-pole fans, but it does not overheat the small fans I use, even at low speed.

 

Then there is this POS. How does this accomplish the job? Anyone tear into one? For 20bucks, I think it's an over priced light dimmer screwing with voltage and not the freq.
https://www.harborfreight.com/router-speed-control-43060.html

 

I bought a Vivitar 786hd for about $60 at Walmart. It's a go-pro like camera. The microphone doesn't work very well when the camera is in it's waterproof case.

 

I think AVE of Youtube fame is shooting his vids with a "SJcam" now. Can't say that I've noticed a difference in his vid quality and don't know what he does for sound. At any rate it's supposed to be a direct competitor to the GoPro line at like half the cost.

Personally I use a Canon point/shoot, and hate it. Video at best is "meh", and the sound sucks. My memory card is waaay too tiny and the battery sucks...lol.

I'm too cheap to buy something specific you workshop vids so I'll probably end of retooling one of my old 'smart' phones for video purposes. What I would love is to download in realtime to my laptop to save on the file transfer time, and take device memory out of the equation.

 

Electric stove element controls... Now THERE is a good idea. And I just throw out the top half to my stove a couple of years ago. (powder coating oven)
I checked the dimmer switch in the video and she's rated to 600 watts. HD sells them in many different sizes. This all came about at when my wife recently said a dimmer in our home felt pretty warm to the touch in the living room. After measuring the metal temp behind the wall plate, it was 135 degrees! That of course set off warning flags and after checking watts on the light bulbs on the chandelier (480watts) and the dimmer is rated for 500watts. Funny thing, that dimmer gets warm when the bulbs are at full brightness. I would have thought it was the other way around when dim. I guess it's true these are really more electric choppers and not of the resistor variety. Learn something new each day.
Wild stuff.

 

I think it uses the same waveform clipping to reduce voltage.
Note that it specifies use with an universal motor with brushes, although I have used them with shade-pole fan motors too.

Now that I think about it, I guess there are PWM commercial variable speed drives that change the pulse width (pulse width modulated).
The technology has changed so much over the years that it is difficult to keep up with exactly how they are doing it.

I prefer a mechanical damper to control combustion air flow because menchanical dampers never break, but having said that I bought a new Toro leaf blower for my new furnace, and it has built-in variable speed control that I will be using.

 

I will take a look at that one.
I don't want to put a lot of money into a video camera, but I would like a small one just to keep record of what I do, and be able to review mistakes I make during the process (and record casting disasters heaven forbid should they occur).

 

I looked at several cameras, and the reviews on the inexpensive ones are not very good (good price but lots of malfunctioning units).
I guess I will use my Canon Rebel, and strap it to a helmet or something.
I just can't drop 300-400 on a camera, no matter how small or convenient it is.
I could come close to buying a new Rebel for that.

 

In the flying world.. As a flight instructor I noticed there is this clarity that comes from sitting in the right seat of an airplane watching someone. Extra movements, unnecessary procedures, bad time management, pretty much you name it, I've watched some clown do it while flying. It's often hilarious when explaining this later. The running video exposes our weaknesses as humans when conducting tasks. If anything, it's entertaining as hell. Editing is a wuss way to make stuff look better. There is a guy on youtube called styhexenhammer and everything he does is single take. No editing. Pretty impressive to watch him delve into a complex subject and not miss a beat after 15mins! If only he would put on a damn shirt. lol

 

LOL, I like that guy; he is good.
I always wear a shirt because I have never been able to grow chest hair.
My wife always complains when we go to the beach and I wear my velcro-chest hair accessory.
I think she is just jealous of all the attention it draws.
If I lose much more hear on my head, I am going to get a velcro wig to as a matching accessory.