Sunday, September 2, 2012

David Brooks' Worst Piece

Link to his original post at the New York Times

http://www.nytimes.com/2012/08/21/opinion/brooks-guide-for-the-perplexed.html


That is quite possibly the worst article I have read from David Brooks--A syndicated columnist that I usually enjoy reading because he typically spends his time trying to discover a fresh perspective or back story of some issue which feeds national politics.

Virtually every paragraph is embedded with a silly assumption, false dilemma, lines that beg the question, or blatant ironies.

"The country needs big changes . . "
Does our country really need big changes? No I don't agree with that.  If you really think that the country needs big changes, then it is likely that you believe those changes are already under way or you are a tea party voter who hates anything that Obama has done or will attempt to do.

"What really matters in this election? Well, the big issue is national decline."
While this seems to fit in with the misguided "American Exceptionalism" mantra currently possessing the Republican party, the big issue with voters is still the economy stupid.   But the economy is slowly recovering (including big housing markets like San Francisco and Miami) despite the best efforts of most congressional conservatives.  So the original Republican prime directive of obstructing any recovery long enough so they can blame Obama during the election is shifting to the implied assertion that Obama just doesn't think America is special.

"How can we ensure that the U.S. is as dynamic in the 21st century as it was in the 20th?"
Begging the question.  Does the US need to be as dynamic in the 21st century as it was in the 20th? If so then perhaps we need to make things more dynamic by congress legislating legal gay marriage and opening our borders.

The irony of a conservative arguing for more dynamism!  These are literally political opposites -- conservative vs. progressive.

"The biggest threat to national dynamism is spending money on the wrong things."
Really?  The issue is no longer the classic conservative belief that we are spending too much money, but rather that we are spending it on the wrong things.

I believe the biggest actual threat to national dynamism is a government stocked with people who don't understand science and believe its conclusions and research to be false. (Assuming you accept his premise that the 21st century must be as dynamic as the 20th)

"If you go back and look at the federal budgets during the mid-20th century, you see that they spent money on the future — on programs like NASA, infrastructure projects, child welfare, research and technology."
So now he is arguing for more government spending on precisely the types of things that conservatives have been trying to privatize for two decades.  Now these are the right things I guess.

"It’s increasing so quickly that there is no tax increase imaginable that could conceivably cover it.  And, these days, the real entitlement problem is Medicare."
False dilemma--You must raise taxes impossibly high or cut medicare.  There are many other ways to solve this problem.  For example, you could actually do both along with more infrastructure spending which would create jobs.

"You’re still deeply uncomfortable with many other Romney-Ryan proposals. But first things first. The priority in this election is to get a leader who can get Medicare costs under control."
And here is his central premise.  Romney-Ryan should be elected for trying to debate for a partially privatized Medicare plan that they will likely never be able to legislate even if Republicans win majorities in both the House and Senate. And meanwhile all of their admittedly odious political beliefs which threaten the dynamism of the country are unimportant.

I read this article looking forward to reading some well supported reasoning as to why Romney-Ryan might reasonably attract voters as a ticket. Instead I ended up reading perhaps the lousiest piece David Brooks has ever written.

In my mind, "Guide for the Perplexed" mainly serves to illustrate how bizarro-world American politics has become --"Conservatives" arguing for radical changes in just about everything and "Liberals" resisting with a fatherly tone.

In honor of all this, I think I'm going to re-watch the Original Stark Trek bizarro episode "Mirror, Mirror" in which all the characters have become selfish,  evil "opposites" of their former selves.

Maybe I'll grow a goatee while I'm at it.

Tuesday, August 21, 2012

Flooded Fire Ants

Noticed what appeared to be some brownish weeds in the grass in the middle of a flooded low point in my back yard after several days of rain.


I took a closer look and  . . . 

Fire Ants!

This is one of the many reasons flood waters can be so dangerous.  All the worker ants, the queen, and the brood (eggs, larvae, pupae) escaping to the 'high rise" grass blades above the water.




They can float across the water en masse by locking mandibles like a chain.  The ones below the water can survive off of pockets of air until they reach ground or something floating--In this case the grass blades.

Sunday, August 5, 2012

Old Washing Machine Tripping New GFCI

This post explains how I was able to resolve the issue of my old washer tripping my new GFCI.  This is just a possible solution.  There are other reasons your washer may be tripping a GFCI and some could be dangerous.  Consult a professional electrician if you are unsure of any of this.

One of my summer projects has been updating our electrical outlets with GFCIs where it is required by electrical code (outdoor, garage, kitchen, bath, within 6ft of a sink, etc.,).  This brought me to the GFCI electrical code vs. washing machine dilemma.  

Old washing machines will tend to trip a GFCI during regular operation because the GFCIs are so sensitive.  For this reason many homeowners and landlords have their old washing machines powered by a non-GFCI protected circuit.  Of course, in most cases that is violation of electrical code.

I went ahead and installed a new GFCI into the outlet that powers our washing machine, hoping for the best.



(Not pictured here, but I placed electrical tape over the side terminals before placing the GFCI into the box to prevent any shorts because of the tight spacing.)


Sure enough, our old washer tripped the GFCI twice during just the first load after the GFCI had been installed.

Before giving in and removing the GFCI or buying a new washer, I decided to attempt some cleaning.  An old washing machine is likely to be caked with detergent, dust, and detergent-soaked dust.  This material will conduct electricity and can really build up in and around the control panel and knobs.  Add to that the likelihood that the washer is in a very warm, humid, lint-filled area and there is bound to be some current leaking here or there.



I did a thorough cleaning with a damp cloth on and under the control panel and knobs (with the washer unplugged).  I also used a can of compressed air meant for cleaning electronics to flush the gobs of dust from behind the knobs and wash setting dial.  I let it dry fully (with the aid of a hairdryer, replaced the control panel, plugged it back in ran a new load of laundry.  Ten loads later and it has yet to trip the GFCI again.  It is also likely that I will need to do this as a maintenance routine every 6 months to a year.








Friday, August 3, 2012

Simple DC Electric Motor



This simple direct current electric motor is built from the following materials:
14 gauge insulated copper wire (~3ft)
1 nickel-plated neodymium hard drive magnet or large ceramic magnet (fridge magnet is too weak)
2 large wood screws
2 small wood screws
2 tie wraps or twist ties
Nail polish (just a few dabs)
1 D battery
1 block of scrap wood for the base

The coil is made from 2ft of 14 gauge insulated copper wire which came from a 14-2 romex spool.  Using the D battery, wrap the insulated wire around the battery in tight loops leaving a about two inch tail on each side.  In our case we wrapped the wire around the battery 4.5 times as shown.






Make the tails on each side of the coil as straight and parallel as possible.  The tails should form an imaginary continuous line (or axle) which will be the axis of rotation about which the circular coil will turn.  Use tie wraps or twist ties to wrap the coil in place on each side where the tail starts.  Clip each tail to about 1.5in.

Strip about 3/4in of the insulation off of each end of tail and give the end a an angled bend up on the left side and down on the right as shown here (this will help keep the coil from sliding off the bracket when rotating).



Now use the nail polish to carefully paint just the top side of the right (or left) stripped wire tail.

Next is the task of creating the brackets out of stripped copper wire. They are made from two approximately 6in lengths of 14 gauge stripped copper wire which is screwed into the wood base with two large round-head wood screws.  This wire is stiff enough that it will make contact with the battery terminals adequately without having to add a rubber band etc., and it is also stiff enough to keep its shape went bent in a particular way.





Carefully shape each bracket side so that the tails of the coil can be rested into an S-shape cradle and will form an axis of rotation that is parallel to the wood base.

Next is the magnet placement.  The neodymium magnet should be arranged to produce maximum rotation of the coil.  You may have to experiment with this for a few minutes before securing the magnet to the wood base.  (If the magnet is not secured, the magnetic field resulting from the current flowing through the coil will push the magnet out of position and end the motor's rotation.)

The coil is placed about 1/16in above the magnet center on the magnet as shown.





Here is a simplified diagram of the magnetic field (B) in red produced by the magnet and the current (I) produced through the coil by the battery and bracket assembly.


Using Fleming's Left Hand Rule for motors, the associated force produced upon a particular portion of the coil is orthogonal to both the field (B) and current  (I)


With the coil oriented vertically, you only need to give the coil a rotational push in either direction to produce sustained rotation.  Each side of the coil will "feel" a force which points in opposite directions resulting in continued rotation.  (Again here the magnetic field is red, current is turquoise, and force is green)



The nail polish is necessary to block current from flowing for the portion of the rotation which would produce opposing forces and stop continued rotation.


Here is our simple dc electric motor in action.





Tuesday, July 31, 2012

Hard Disk Drive Disassembly

As a summer project, my son and I took apart this old 60GB hard drive which last serviced a PC running Windows98SE in the early 2000's.  Below are the pictures of our exploration.  In addition to several small phillips-head (crosshead) screwdrivers, we also needed a T6 and T9 star wrench.

Note:  Taking apart a hard drive at home like this will ruin it and make it no longer usable.

Step 1, Removing the outer screws



The PCB/Control Board must be removed to access any screws underneath.




First warranty void sticker--T9 screw underneath.





Top is now ready to be removed.




Removal of top Actuator bracket with nickel-plated Neodymium magnet attached to the underside.


Rare earth Neodymium (Nd2FE14B) magnet is very strong.


Actuator has been removed revealing the second magnet and bracket below.


Both magnets removed.




Removal of spindle collar using T6 wrench.


Now the platter can be removed just by lifting it off of the spindle.


Final diagram of parts:





Thursday, July 26, 2012

GFCI Installation

Installation of two GFCIs (Ground Fault Circuit Interrupter) on the same circuit.
This post shows how I installed two GFCIs on the same circuit correctly without sharing a common neutral or "daisy chaining" them.

(I am not a professional electrician, just a DIYer with some electrical experience, call a professional electrician if you are in doubt about any of this).

Initially, I had installed a single GFCI outlet near the beginning of one of our larger home circuits in an effort to save time and money.  I really only needed the GFCI to protect three outdoor outlets:  Two in the garage and one on the back porch.  Because my first garage outlet was near the beginning of the circuit and my back porch outlet was at the very end, I installed a single GFCI in the garage to protect all three outdoor outlets as shown here in a simplified version.

My Original Circuit Wired with One GFCI Protecting Everything
(Caused me occasional nuisance trips)


My newly bought GFCI was manufactured with the Line side on the top terminals which I have depicted in my diagram.  This makes more sense to me logically to install the top Line wires first and then bottom Load wires next. Having the Line side on the top terminals seems to help emphasize the idea of the Load side being downstream in the circuit. The older GFCIs that I installed 10 years ago came with the Load side on top.

If you are lucky, a single GFCI outlet can be installed to protect many outlets downstream.  The problem is that a GFCI outlet is very sensitive and the more outlets it protects, the more likely you are to leave something permanently plugged in that will cause some nuisance tripping.  My problem may have come from the fact that this one GFCI was actually protecting 15 different outlets or wired items.

Every two to six weeks the GFCI would trip shutting down all fifteen of these items at various times of day seemingly independent of what was powered by the circuit at the time.  That frequency was seldom enough to make it nearly impossible to identify the source of the current leak.

To make matters worse, the outlet would trip leaving my family occasionally locked out of the house because it fed power to our garage door opener.  I suspect that the problem may have been one or more of  these possibilities:
1.  The battery charger on our older laptop
2.  A dirty potentiometer in an older piece of equipment on our stereo
3.  The wiring inside GFCI box such as a side terminal too close to the grounded box (likely)
4.  A faulty GFCI (rare)

I finally gave in and rewired the circuit with two new GFCIs such that all the outlets and lighting in between that did not need to be protected by a GFCI were left out of the downstream portion of the first GFCI in the garage.  This solution addressed all of the four possibilities listed above.

Circuit Wired with Two Isolated GFCIs


I added a pigtail splice and wire nut for the hot and neutral sources so that the Line side could be split.

Note:  The pigtail splices and wire nuts are not necessary in this particular situation and could have been left out by simply connecting the hot and neutral from the right branch of the circuit above to the extra Line terminals of the first GFCI (The hot and neutral circuit nodes can exist at the Line terminals of the GFCI or at the pigtail splices).  The pigtail splices make the diagram look a little more clean and easy to read and would need to be in place if there were another Load branch in the circuit that needed to be isolated from the GFCI.


This circuit wired without pigtail splices using the duplex Line terminals


You will notice that the garage door opener is still on the Load side of a GFCI protected circuit branch, but it is now grouped together with only a few other items.  The garage door opener is plugged into an oulet in the ceiling of the garage which is subject to a great deal of humidity and moisture, so I chose to leave it on the Load side of the first GFCI.  Had I chosen to exclude it, I would simply have disconnected the hot and neutral wires from the Load side of the GFCI  and joined the opener's wires to the appropriate pigtail splice at the top.

The circuit wired so that the GFCI does not protect any outlets downstream

If I continue to have occasional nuisance trips on the circuit, I will wire as shown above.  The pigtail splices are already in place if this becomes necessary.

The remaining pictures show how I installed the new garage GFCI in place of an existing GFCI outlet.  Originally there was a simple duplex outlet at this box, so I will mention how I found the Line side and Load sides of the circuit when I initially wired the old GFCI.



Don't forget to turn off the breaker to the circuit you are working on first!
I carefully identified each set of 12-2 wires in the box.  This can take some time with three sets of wires.  One way to do this before you actually remove all the wiring from the old plug is to remove one set of hot and neutral wires at a time and tape them off with electrical tape or a wire nut and then turn the power back on and see what is still powered.  If the plug you are working on no longer has power, then you just removed  the Line source side.  If it does still have power then you have removed one of Load sides of the circuit.





*Be careful to remove the wires in hot/neutral (black/white) pairs making sure that the pair you are disconnecting come from the same 12-2 insulated cable.  Several of the duplex outlets that I have replaced in my home were originally wired such that the hot side wires and the neutral side wires were screwed into terminals in no particular order.  In other words, it is very possible that the top terminals in the back or side of the outlet have a neutral and hot from different 12-2 cables.  This doesn't matter with a simple duplex outlet where the outlet is just a node on each side, but it makes a big difference when wiring a GFCI.*

Because the existing outlet box could not really adequately accommodate the larger size of the GFCI and the amount of wiring including splices that had to fit behind the new GFCI, I had to remove the old box and replace it with a new larger 1-gang plastic box.


.




I now added a couple of short jumpers from the to Line side of the GFCI.  These will connect to the pigtail splices in the box.


Next I connected one of the grounding wires to the actual ground terminal on the GFCI.  Notice that the other grounding wires are pigtailed to it further back.


Here I have screwed in the set of Load wires from the portion of the circuit I want this GFCI to protect.


Next I pigtailed the remaining hots and neutrals together respectively with a wire nut.




Use a receptacle tester to double check your wiring once the outlet is secured into the box and the power is on.


Here is the finished GFCI and wall patched with small piece of drywall and lightweight spackling.


Finally, I moved to the easier job of replacing the outdoor porch receptacle with a GFCI and new cover.


Notice this GFCI has it's Line side on the bottom terminals and the Load terminals are unused because this is conveniently the end the circuit.

This receptacle was installed in the concrete block on my back wall, so I was determined not to try to replace this older box with larger new one as I had to do in the garage.  There was only one set of wires and ground coming into this box, so I was able to get the GFCI to fit.

Given the tight space, I added some electrical tape to each side of the GFCI to help prevent the possibility of the side terminals grounding to the box.


Now the cover.






Again, here is the final wiring diagram for the circuit as it is now.