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   Did a quick project that I got parts for the other day.  I have a blower in the rafters to help force warm air down.  Initially when I wired my temperature-based fan controller, it simply switched the fan on, and back off after the heater turned off.  However, I would like to run the blower on a lower setting when the heater is off so that air is constantly being moved out of the rafters. 
   To do this, I picked up a relay and a ceiling fan capacitor.  Both are inexpensive, and although with two extension cords, a light switch and an electrical box I had all the parts I needed to put this together.  The circuit is simple.  The fan capacitor slows the fan down when placed in series with the fan.  The relay is a double-pole, double-throw relay with AC coils (i.e. it switches with the application of 120 VAC).  The normally closed part of the relay is setup such that the power comes into one of the delay contact, goes through the fan capacitor, and back out the other contact.  The normally open part of the relay is simply shorted together.  Thus, when the relay is unpowered, the fan capacitor is active, thus slowing the fan down.  And when the relay is powered, the fan runs at full speed.  I can use my thermal switch just like I was before.
   The fan capacitor I picked up actually has 3 capacitors in it so the fan could be set to various speeds.  I might have to play with the combinations until I find one that gives me the lower speed I want.  Otherwise, I'm pretty happy with this setup.

2 comments have been made.

From Noah

Underground

February 21, 2021 at 5:59 PM

Cool project! I have to admit, this is the first I've heard of a cap being used to adjust the speed of an existing motor. My first thought was that it would consume lots of power in comparison to a triac dimmer just cutting off parts of the AC phase...

From Andrew Que (http://www.DrQue.net)

Middleton, WI

February 22, 2021 at 9:30 PM

Yes, a triac will work to control fan speed but at a cost: audible buzz.  This happens because a triac dimmer abruptly cuts off the AC power during the AC cycle and the harmonics from that high frequency edge creates causes the coil in the motor act like a speaker.  You can sometimes hear the buzz in incandescent lights.

An alternative is to take advantage of inductive reactance using an LC circuit.  In this case, our motor is the inductor.  Adding a capacitor to an inductive AC circuit is like adding a resistor.  It lowers the overall current and thus the motor cannot run as fast.  And unlike a triac there are no audible side effects.  Ceiling fans with a pull string often use capacitors for speed control.  This is the source for the capacitors I am using.  The down side is that the capacitors don't last forever and degrade over time, which is likely why these capacitors are easy to find.

There has been a lot of hype browser fetchers to prevent tracking. What bothers me is that preventing tracking isn’t all that complected. By default I block cookies from all websites and I’ve done this for most of my web life. That right there takes care of most of the tracking. I also disable Javascript on all websites that don’t need it. This is becoming harder and harder as more sites are relying on Javascript to run. Still, plugins like uMatrix allows you to enable Javascript and disable XHR (XML Http Requests). That helps prevent tracking. Sites like Amazon send XHR when ever you focus on a different tab and some sites send XHR to track your mouse movement. Even with XHR disabled, sites like Google will change the URL of links when you click them so they can track which links are clicked. And even with Javascript disabled, Amazon embeds tracking references into the URL of every link so even if you disable cookies and Javascript, they can still track you.

Now there are browser fetchers that specifically target tracking sites. They are just blocking cookies so nothing I haven’t been doing for years, and they fall far short of really stopping tracking. However, I’m concerned about this. The more browser fetchers are added to protect users from tracking, the more innovative companies tracking people will become. Right now not being tracked by the major trackers doesn’t take a lot of effort. But the more browser fetcher that are added to nuder these sites, the more crafty these sites will become. My toolbox of cookie and script blockers might not be enough in the future.

As a user you have no rights your browsing privacy on the Internet. Many of the companies on the net make their money from this fact. Google and Facebook/Twitter/Intsagram make their money from your digital footprints and they are very good at stalking you. Right now they let you seem them do it and have no shame. But if everyone starts trying to cover their tracks be assured they will just give up.

Que Tries to Weld

Que Tries to Weld

   So I need to reinforce my primary shelve and I was torn on what method to use.  I've decided to try using large 16" shelving brackets in a hanging configuration.  The shelve brackets I want to use have a 45° support.  However, these are not designed to be hanging and so this support isn't connected too well to the rest of the frame.  This typically doesn't matter since in the normal configuration the weight of the shelve would simply push the support bar tightly against the edges.  In the hanging configuration the situation is reversed and the weight of the shelve wants to pull the edges away from the center support.  So I wanted to shore up the connection. 
   I've tried welding once before and the results were pretty miserable.  Still, I have the tools and this seemed the best way to make sure the bracket support would not separate from the edges.  So I watched a couple of stick welding videos and decided to give it a shot.  I guess that's what I needed as I made several test welds that were vastly superior to my initial attempts.  After using a grinder to remove the paint, I put the brackets in my vice, decked myself out in PPE, and started heating metal.  The first couple of welds turned out the best and I really built up the metal support connection.  The latter welds I ended up cutting some of the support away but still made a large pool of metal around the connection.
   The welds are ugly but the brackets are likely strong than when they started.  A quick grinding and a coat of black spray paint and they should be ready to install.

1 comment has been made.

From Noah

February 12, 2021 at 10:13 PM

Looks pretty darn secure if you ask me!

Don't forget, it would be my pleasure to hook you up with some industrial grade adhesives.