2017-11-05

Using Recovery Mode on my Lux Thermostat

I've had this Lux programmable thermostat for years, and it's worked perfectly great for me.

But this week I just learned about enabling Recovery mode, and it both works great and should save me more money.

What is recovery mode?

Normally, a programmable thermostat is a device that is used to turn on the heat at a user-specified time in order to meet a user-specified temperature.

In contrast, a recovery mode programmable thermostat is a device that ensures that a user-specified temperature is met at a user-specified time.

The difference seems subtle, but in the real world, recovery mode makes a big positive difference in terms of living comfort and heating efficiency.

When using a thermostat, it can take a variable amount of time for your heat to come up in the morning.  Let's say you want to be up and about a 7 AM with a house temperature of 68 °F.  When should the heating system come on?

Well, that depends on your heating system, how cold it is outside, and how cool your house is.  If it was warm last night, with a low temperature of 67°F, it will take only a few minutes of heat to get to temperature.  But if it is cold, say down to 60°F inside and 20°F outside, it could take an hour for the heating system to suitably warm up the place.

A thermostat's recovery feature automatically figures out when the heat needs to come on in order to reach the programmed temperature at the right time.

I generally want to keep my house at 68 °F during the day (from 7 AM), and I set the thermostat to 60 °F at night.  I don't want the heat to turn on at 7 AM - I want the house to be 68°F warm at 7 AM.  With recovery mode, I just program my thermostat to "68 °F at 7 AM", and from there my thermostat works to make sure that's true.

The thermostat uses the current temperature, the goal temperature, and the recently recorded speed of the heating system to figure out when to turn on the heating system.  Today the thermostat might calculate that the heating system needs to come on around 6:42 AM to reach 68 °F at 7 AM.  When it is much colder next week, the thermostat might determine that the heating system needs to be turned on at 6:35AM.

In all, this means that the thermostat will work as efficiently as it can in order to keep my house at the right temperature for me.  All this in a $50 thermostat.  Pretty nice.


2017-09-26

MagSafe Power Adapter Repair (and failure)

Every Apple site has users that complain that Apple MagSafe Power Adapters can fail... but nobody says what you can do to fix them.

I happened to buy an old MacBook and it came with an unreliable MagSafe power adapter.

How can Apple, after producing this general style of AC adapter for over 15 years, manage to continue to make a power adapter that fails?  More confounding, I've purchased a number of MacBooks over the last decade, and I have never had a problematic MagSafe power adapter.  What gives?

The simple answer is: Customer Abuse.

I've actually had my hands on at least 10 broken MagSafe power adapters, and in every single case the failure was caused by customer misuse.  Here is the list of failures I've seen:
  1. Cat or Dog chewed cable
  2. Pinched cable (crushed from furniture or a door or something)
  3. Over-stressed cable (from repeated yanking, over-winding, or some other abusive behavior)
And that's it!  In no case have I seen a MagSafe charger fail from any other cause, although I suppose that lighting damage and water damage also happens.

So, what do I do about it?  My answer is to replace the cable!
  1. Remove the power cable or duckhead from the MagSafe adapter
  2. Crack open the MagSafe adapter using large needle-nosed pliers
  3. Remove the old cable using solder wick and soldering iron.
  4. Solder in new cable
  5. Close the MagSafe adapter, lashing with tape
  6. Verify proper operation with a voltmeter
  7. If successful, use epoxy to re-seal the MagSafe adapter
I've never had a repair of this nature be anything other than successful.

That concludes what I do with a misused MacSafe adapter.

2017-08-29

Saving an iPhone 6 from Water Damage

The other day, my cousin was thrown into a pond with his clothes on.  You know, a really funny thing, unless, of course, he has his iPhone 6 in his pants pocket.

Panic ensued.  "Quick!  My iPhone!  It got wet and is acting all weird!  What can be done?  Should I get some rice?"

The reality is that rice cannot absorb a significant amount of water from the inside of a tightly-constructed device.   Happily, I was there, and I happened to be there with my small electronics tool kit.

The iPhone was powered up at the time it went into the drink (no surprise), and the screen was flickering. It was back at the Apple logo, and it soon fully booted.  But the display was fading in and out.

How I saved this iPhone 6:

First, I tried to power it off.  No luck!  It wasn't turning off.  Nothing was actually working.  So I grabbed my small electronics tool kit and opened up the iPhone.  I'm very familiar with iPhone disassembly and needed no instructions, but then again I've worked inside dozens of iPhones.  Most people can use the ifixit guide for help.  But remember, time is of the essence!

Upon opening, dang, there was water EVERYWHERE.

I quickly disconnected the battery and used some facial tissue to mop up some of the water.

From there, I removed the display, the SIM tray, and the logic board.  Of course it is important to keep track of all the little screws - and that's not so easy in the heat of the moment.  I continued to mop up the water along the way.

I didn't remove any other parts - so I basically had the logic board in hand.  I made sure everything was as dry as I could make it with some tissues.

The Somewhat Aggressive Dry-Out

Then I turned on the kitchen oven and set the temperature to 165 degrees.  I put the logic board alone in the oven on a piece of parchment paper and let it get nice and warm for a few hours.  I flipped the board several times over the hours to ensure there was decent airflow over the entire board.  My intent was to help quickly evaporate any hidden water remaining in, under, and around logic board components.  I left all the other parts (the housing with battery, and the display) in a safe, airy place to dry out.

Later that day I put some dry silica gel packs in  tuperware container, and then I added all the iPhone parts to the container.  I sealed it all up and let it sit for two days.

After those days went buy, I opened the tuperware container and inspected each part.  All of the little formerly-white water damage indicators were triggered red, but otherwise it all looked good, with no evidence of water and no water stains.   I re-assembled the phone and powered it up.

The phone successfully started (yay!), and then I tested each feature of the iPhone.  It worked perfectly, except that there was a little bit of staining under the glass of the display panel.

Success!  An iPhone saved from serious destruction.  I am confident that if I left the phone alone, all that water would have done a lot of damage.


2017-06-20

Five reasons for running a dishwasher overnight

A few weeks ago I tried to wonder why I run my dishwasher overnight.  I set it to run at about 4 AM or 5 AM, and it finishes up by 6 AM or 7 AM or so.  Here's a conclusion of my analysis.

Electricity is more efficient overnight, and therefore costs less and emits less carbon.
Power companies produce less electricity at night due to lower demand.  During the day, they produce more electricity.

As for-profit entities, power companies want to use as little fuel as possible - after all, their biggest expense is fuel. So the plants that they run all the time are their most efficient plants, and the plants that they add during peak times - during the day - are their least efficient plants.

By running my dishwasher over night, I am guaranteed to be using the power by the most efficient power plants.

Winter Heat / Summer Heat
My dishwasher releases quite a bit of waste heat and moisture.  Most of that heat from the dishwasher stays in my house.  By running my dishwasher at the the early morning, all the heat released pretty much stays in my house, to keep me incrementally warmer right when I awake.

Similarly, I don't want that heat in my house in the summer during the peak of the hot weather.  By running it in the early morning, the dishwasher waste heat doesn't add to an already super-hot house.

Waste water
The waste water produced by my dishwasher gets dumped into the sewer earlier in the morning.  This avoiding the peak time of wastewater production.

Hot Water Heater Cycling
By running the dishwasher in the early morning, the hot water heater gets busy heating up replacement water right before I get up to take a shower.  This puts less thermal cycling on the hot water heater.

Noise
I don't want to hear my dishwasher run.  I don't hear it while I sleep in the bedroom.

Quick drying
I like to open the dishwasher right after its cycle so its contents - particularly plastics - dry quickly.  Since I get up as it is finishing its cycle, I am often there to open the door and let the ambient environment quickly dry its contents.  By the time I'm ready for work, I can empty the cool and dry contents of the dishwasher.

---

There we have it!  That's why I run my dishwasher overnight.  Perhaps each line item has an extremely tiny impact, but perhaps when taken in their totality they are a little less than tiny.  Let me know which ones you think are bull - and why.



2017-06-16

Fixing the bottom rubber of a mid-2010 or late-2009 MacBook

All my regular readers know that I love the late 2009 and mid-2010 white unibody MacBook notebooks.  They're robust, they're still very capable, and they can still run the latest MacOS.

One problem with these old beasts is the bottom rubber can detach.  Apple used to provide free replacements, but that program ended more than a year ago.

So what do you do to fix the bottom?  It's easy!  Here's what I did:
  1. Remove the bottom plate by removing the 8 bottom screws.
  2. Fully peel off the failed rubber and fully expose the aluminum.
  3. Use small pieces of permanent tape on the "back side" of the lid to cover the drill holes in the aluminum.
  4. Fully clean the "exposed side" of the aluminum plate.
  5. Apply small stick-on rubber feet to each corner.
  6. Coat the "exposed side" of the plate with several coats of Plasti-Dip spray paint.  I picked red, but there are many colors available.
  7. Re-attach the bottom plate to the laptop.
There we go!  Now I have a nice rubberized bottom plate once again.  It looks great, it is stable, and it only cost about a quarter can of rubber paint to repair.

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