Sunday, October 24, 2010

My Brother Stan. April 16, 1955 - December 4,2010

 This is a photo of my beloved brother Stan when he worked in the library of Lebanon Valley College.  These were some of his happiest years, coming after the acceptance of the death of his first wife, Jane.  She died of lupus at 33.  However, that same disease that took her away is what first brought them together.  You see, Stan had a severe  autoimmune disease of his own, Ankylosing Spondelitis.  Like Jane, he contracted that at an early age, in his case, 14.  Their respective suffering helped form the close bond they had.   Stan had numerous operations beginning around 16, when the doctors attempted to straighten his increasingly twisted body by putting him in a body cast for many weeks.  Other operations followed, and he had to miss a year of school.  Over the years his hips, knees, elbows, wrists, ankles, and jaw were operated on.  In some cases, like his wrist, they simply eliminated the joint altogether and fused the bones. There simply wasn't enough left to work with.  The ragged bones destroyed the tendons controlling some of his fingers, so two fingers were linked to one tendon.  This of course meant that those fingers no longer moved independently.  Some of his toes' joints disintegrated to the point that the tendons began to pull the toes sideways, then towards his heel. In this case, amputation was the best remedy.  The disease caused Stan to develop a severe overbite.  This required surgery that still gives me the chills.  They cut his upper jaw out of his head, shortened it, and put it back.  Double hip replacements helped somewhat,  but there isn't much one can do with an arthritic spine except for fusing the worst vertebrae together.  While that may alleviate the pain and pressure on the spinal column, it takes away even more freedom of movement.  While the arthritis showed no signs of slowing down, Stan refused to slow down.  He had to accept the inability to play sports years ago, but giving up music was something he did not want to do.
 That meant finding an instrument that he could play given his limited movement.   The hammered dulcimer provided the perfect solution.  I built him his first one, and while it worked, it was not very good.  So, together we built a much more refined one, and he became quite good at it.
Then we rebuilt his house to make it more handicapped accessible.   The original house had a cramped bathroom with a tub that was difficult to step into. In addition, the laundry room was in the basement.  When working with the original house proved too difficult, we had the rear half of the old house completely demolished.  Then we had that replaced by a much larger wing that held a modern kitchen with laundry, and a nice master bedroom with generous closet space.  The old bedrooms were so small that we turned one into a master bath.  As a bonus, the new addition had a bright basement that was more easily accessible, for it required just a few outside steps to go down.
  This gave Stan room to practice what had become his primary hobby, model railroading.
  As nice as the house was, something important was missing.  Love and companionship.  A long standing friendship soon became something more, and he married his loving and supportive wife, Linda.   These were very good years.

Then last year Stan became ill on a trip with me to visit fellow model railroaders. In particular Wally, for whom I designed and built the table seen in my blog.  We had no idea what was wrong, but Stan soon found out.  A stage 4 malignant brain tumor.  He was told he may have as little as 6 months to live.  That was a year ago, and he is still alive thanks to some very good care, but the disease now has the upper hand.  In a tragic irony, it is the exact same thing that killed our father in 1958. Stan was 2 and I was 6 months.
  Stan did not quit.  While he was forced to give up driving, and soon after his job, he continued to build model railroad cars with meticulous detail.  Some of them won prizes in regional competitions. Some pictures of Stan and his cars are below.

Stan lived to see my birthday, which was Oct 23. We had a great time together.  It is his goal to see Christmas.  Let's pray that he makes it!

Tuesday, September 21, 2010

A home for my Mom

Late last year, my then 88 year old mom began to fail and could no longer live alone. Not a believer in warehousing the elderly, I built her a specially designed addition to my home.

The roof was the trickiest part of the design, thanks to the second floor shed dormer and the small pieces of roof on either side.  A simple shed roof would have had a very flat pitch and looked unattractive.  My solution was a hip roof.  While much more complicated to build, it allowed for an increased pitch and tied in nicely to the existing roof-line.

My very capable Amish contractor, Amos, liked my design but soon realized that some very unique trusses would have to be made for this job.

What I found interesting about this design is that none of the load is carried by the existing structure.  Instead, the trusses span 34 feet from side to side, and there is one massive truss that supports many smaller trusses at right angles.

A very strong design, but one that was difficult to insulate, thanks to the many odd spaces it created.

I spent hours cutting fiberglass to fit neatly in all of theses spaces.  It paid off, and the addition stayed comfortably cool with minimal air-conditioning this summer.

The bathroom was a real challenge.  The first floor had a powder room that could be enlarged into the addition.   I wanted a large shower and direct access to my mom's bedroom, but without using a lot of floor-space.  I also wanted a shower that one could wheel into, if handicapped.
  My solution was a shower area that was 48" x 54" and had a tile floor that drained to the center. When taking a shower, the area is closed off via a curtain that rides on hospital grade ceiling tracks. When not using the shower, the curtains are pulled back and one simply walks through to use the bathroom or exit the original door.
  An unusual design, and one that my contractor had some misgivings about, until he saw the finished product.  In the end, it works well, looks attractive, and only used 18 square feet of space in the new addition.
The tiling was a challenge, thanks to the multiple inside and outside corners, and the sloped shower floor.  But I like tiling,
and this is only the latest of several bathrooms I have done.

It is a bright and cheerful space, with plenty of room for my mom's furniture.  Far more than she could have taken with her to a retirement home.
If you noticed the missing trim above the doors, you can relax.  All of those little details are now complete.  I felt it was more important to move my mom in quickly than worry about having everything finished.

My mom and my cat in her new living room.

As my mom's health has declined, I've had to add some refinements, like a ramp to the door, and a new 4 foot wide walkway.  There were only 2 steps before, but now even a single step is a problem.

I also added a shower chair, and grab bars in the shower and on the wall opposite the toilet.  The toilet assist bars were easy to install and work well.  This should make life a lot easier for my mom.

Friday, September 17, 2010

Solar Electric Upgrade

While my 4.4kw solar electric system was performing to specifications, size does matter.  Unfortunately, my budget and choice of suitable locations were limiting factors.  As a result I had a system that could only deliver 620kwh/month when I was using 1800kwh during our hot and humid July.  My solution was to create a new mounting site over my southern facing coal bin.  In addition, I designed and machined my own mounting system.  This greatly lowered the cost, and it also gave me a system that I could not find anywhere:  One that is both roof-mounted and has adjustable tilt for summer and winter.
Fortunately for me, my PV Powered 4800 inverter had the ability to handle the 5 extra panels, bringing my cost per watt down to a very reasonable $2.50, installed.  The result was a substantial 31% increase to 5.58kw and a summer monthly output averaging 812kwh.  While still far short of July's 1800kwh, it will produce a surplus in the spring and fall, when demand drops into the 600's.
Close up of the hinged mounts.  I used the identical design for both the top and bottom rows.
However, only the top row mounts function as
hinges.  The bottom row mounts are separated at the hinge pin and a 24" piece of square tubing is
placed between the hinge halves.  Bolts are then inserted through the hinge pin holes to lock the tubing in place.
These hinges allow for 22° of movement, a few degrees less than ideal.  However, achieving more movement would have required taller hinges, which would have put more stress on this design than I desired.

Panels in the winter position.  I designed the 
coal bin roof with a 45° angle.  Not the optimum
winter angle for our latitude, but a good compromise between the requirements for the coal
bin and the solar panels.

Panels raised 22° for the summer months.  Not the optimum setting, but close enough.  Overall, I'm pleased with the design.  The tilt can be changed in a matter of minutes, and even 22 degrees gives me a significant advantage over fixed systems.

After panels are raised, a link with tapped holes
ties adjacent panels together. The bolts now serve
2 purposes, attaching the legs and linking the
panels. The result is an extremely rigid structure
that does not move even in the strongest winds.

The system has been in operation nearly one year, and has performed very well, even through our cloudy winter.  The winter output is surprisingly good, given that the system had to cope with snowstorms and fewer daylight hours. Below are charts of the electric production, my consumption, and the amount the system is saving me at our current rates of $0.15/Kwh.
Under my current agreement with my utility, excess production gets rolled over into the following month.  That reduced my November bill by $15. The May surplus was $13. That, along with the 800kwh the system made in June, reduced the bill from what would have been $161 to only $28. Since the system was installed, it has made 76% of my electricity. 
Last year, the propane hot water heater failed, and I decided it was more cost effective to use a 60 gallon electric water heater as the backup heater for the Reynolds Solar heater.  This has proven to be a good decision, for my propane use for hot water dropped to zero, while my electric bill remains low, if not zero. 

Sunday, April 11, 2010

Chicken Surgery

I can now add the category of "Chicken Surgeon" to my list of skills.  This skill came by necessity when our guinea hens attacked and nearly killed a favorite chicken.  When I realized she was missing, I searched the pine trees for her, and found her badly mutilated.  A patch of skin over 2 inches long and a half inch wide was missing from the top of her head and extending down her neck.
I realized that the only chance of saving her was to stitch the wound closed.  Unfortunately, so much was missing that I couldn't stretch the skin that far. So, I did the best I could.

Remarkably, she flinched only a few times as I stretched the skin and sewed her head back together.
The first couple of days were difficult for her, and I wasn't sure she was going to pull through.  Large areas of the surrounding skin turned an awful blue-green color.  But she recovered and is doing well.

Five days later, she is happy and active, and her skin is now a healthy pink.  There is much healing yet to come, and for now she must be segregated from the other chickens, who readily attacked wounded members of the flock.  
    Only 12 days later, new feathers began to grow, replacing the ones plucked in the attack.
A month later, feathers continue to fill in nicely, but the hole in her head remains.

 10 weeks later, the scars are nearly gone.  Only a thin spot in her feathers is still visible.  She is now her old self again, and back on the job, laying eggs.

Update:  It is now over a year since the attack and surgery.  She remains healthy, and it is now impossible to see any scar tissue anywhere.  Remarkably, she appears to have either grown feathers in the scar tissue, or somehow shrunk the scarred area.

Wednesday, March 24, 2010

4 KW Solar Electric

We have begun an exciting new project, a 4kw Solar Electric system. It is being installed by the capable team from Clean and Green Alternatives.  It is our hope that this system will have the same effect on our electric bill as our Reynolds Solar Hot Water system has had on our propane bill.  Our system presented some challenges to Clean and Green. Our roofs were not suitable and I did not want to use valuable orchard and garden space for solar panels. Neither did I want the panels blocking any of our rural scenery.  Therefore I had them squeeze the system behind our garage and put it on tall poles to avoid any shadows.  This changed the engineering requirements dramatically, requiring much stronger poles and a whopping 4 yards of concrete, poured into 3 foot diameter foundations.
This required a large concrete truck.  Too large to get behind the garage. Therefore, a mud buggy was required, too.
It took about 9 trips to transfer all the concrete to the worksite. A little over a yard went into each of the 3 foundations supporting the nearly 1,000 pound support structure.

 The support, ready for panel installation:

The panels, waiting for installation:
Sixteen 280 Watt Grape Solar panels.

The panels went up in less than a day. It is an attractive and nicely engineered system.  There is 330 square feet of panel area.  The combined weight of the panels is 890 pounds and the racking is around 300. The poles add a few hundred pounds more, and they are set in 16,000 pounds of concrete.  It becomes easy to see why these systems remain expensive.
  The inverter, a PV Powered 4800 Watt, is a solidly made unit which can produce power even when the panel output is very low.  I've observed it making as few as 50 watts before shutting down as dusk.

True, 50 watts is insignificant. But the system's low light efficiency pays off on a cloudy and foggy day like today. The system produced on average 400 watts under a solid overcast, and 4kwh for the day.  That alone would be enough to reduce our electric bill by 10%.  But of course a solid month of rain would be rare, and in normal weather the system should produce 500kwh/mo.
The early results are encouraging.  The system has been running 3 weeks through a variety of weather conditions. It has averaged 19kwh/day, which equates to 570kwh/month.  That should result in us having  electric bills near zero for 2 - 3 months each year and substantially reduced ones for the remainder.
PV Powered has a great website which monitors the inverter and records the output. You can then download a variety of performance data, like the chart on right.  It also monitors for any problems that might develop.
As we accumulate more data, I will update the results here.  Update.  I increased the size of the system, click  here to see it.

Saturday, March 13, 2010

1965 PHILCO "Florida" Heat Pump

Ok,.so.what makes a Philco heat pump Blogworthy? For one, it is a Genuine Philco, and I love all things Philco.  Second, it is one of the earliest examples of a residential heat pump you will find anywhere. Third, it is approximately 45 years old and still runs great.

I'll admit the age is a guess.  It was made after Ford's acquisition of Philco in 1961, but before Philco was renamed Philco-Ford Corp in 1966.

Whether it was 1962 or 1966, it is a remarkable achievement in longevity and reliability by a very well-engineered Philco product.

I acquired it about 14 years ago from friends who bought an old house which included the Philco. They used it until it quit from a failed capacitor, a $6 part.  Knowing my affinity for Philcos, they gave it to me. It sat in my garage for 12 years, patiently waiting for the day when it would once again pump heat.  That day finally came with the completion of my workshop.  After a thorough cleaning and replacement of the capacitor, the compressor rumbled to life after it's Rip Van Winkle slumber. Soon, it was pumping out 9500 BTU's of cold air.  Back then there was no such thing as EER ratings, but it calculates out to 6.1, typical of the era.  I'm not sure how to calculate efficiency as a heat pump, but it is very effective above 40 degrees F and OK as low as 32 F.  In both modes, it effectively conditions my 576 square foot workshop.
  The heat pump is hardly more complicated than a conventional air-conditioner.  There is one solenoid valve to reverse the Freon flow, and that's about it.  Apparently by design, the solenoid releases all pressure (with an audible hiss) when the thermostat cycles in heat mode. this appears to be necessary, for the thermostat cycles more frequently than it does in cooling mode.   Those who were interested enough to read this far may be interested in another unique design attribute. The airflow,  both on the evaporator and condenser sides, is reversed from the norm.  Inside, the fan pushes through the evaporator, which is tilted back instead of vertical. This insures that condensation does not dribble out the front.  Outside, the fan draws through the condenser and then blows the warm (and potentially moist) air over the compressor. At first I thought that somehow the fan was spinning backwards, but that is how it was meant to run.  And, after 45+ years of dependable operation, who am I to question Philco's engineering?
All in all, a nice design that was apparently ahead of it's time, for heat pumps did not become popular for several more years.

Update:   It is now in it's third year of operation in my workshop, and continues to do a fine job.  The great heatwave of Summer 2011 has made working outdoors unbearable.  Yet even with 100 degree temperatures outside, it was a comfortable 78 degrees inside. A good performance, considering the workshop is a steel sided garage with only one inch of foam insulation, and was baking under intense sunshine all day.

Friday, March 12, 2010

Oil-Fired Power Plant Simulator

How to build an electrical power generating plant simulator, or Having Fun with Op-Amps.

    Way back in the late 1970's, I attended one of the premier technical schools in the country, The Williamson Free School of Mechanical Trades.
 Enrolled in the Power Plant program, we obtained "real-world" experience by generating our own electricity using a Babcock and Wilcox boiler, a 200kw steam turbine, and 150kw Detroit Diesel generators.  While the associated classroom theory was invaluable, there is no substitute for hands-on learning, and the responsibility of keeping the lights lit for the entire campus.  Allow a blackout to happen, and the feedback from classmates and instructors (who mostly lived on campus) was immediate.  Sadly, rising energy costs brought to an end the 90 year tradition of being off-grid shortly after I graduated.
    In my junior year, Omnidata, a company in the business of making sophisticated simulators to train power plant operators loaned us one for a brief period.  That inspired a classmate and I to build one for our Senior Project, which is Williamson's version of a Thesis.
    The microprocessor had been invented only a few years before and the first low cost computers, like the Sinclair ZX81, would arrive a few years too late.   That left a technology that is under-appreciated today, analog circuitry and versatile IC's like the Operational Amplifier, or Op-Amp.  These were relatively inexpensive and easy to use.  A thin book covering the basic Op-Amp circuits was all we needed to get started.  The Op-Amp got it's name from the fact that it does mathematical operations: Addition, Subtraction, Multiplication, Integration, and others.  But these were all we needed, along with a simple digital function, known as a Comparator.  This simply gave a Yes or No answer as to whether the voltage it was monitoring was above or below a certain value.

Addition: Input Voltages 1, 2, & 3 are added    together.   Equal resistor values gave each input equal weight, which is how we used them.  A good deal of the Op-Amp's versatility came from the fact that it could accept both positive or negative voltages, which would subtract.  Another way to achieve subtraction is to connect to pin 3.  This is the equivalent of changing the sign of the voltage.

See the Difference Amplifier at right:

V Out is the difference between V1 and V2.
Combining elements of the summing and difference amplifiers is possible, giving one the ability to add and subtract multiple input signals.

The heart of the simulator was the Integrator circuit:
This functioned as an analog "memory" in our simulator, with the voltages stored in the capacitors representing things like the water level and steam pressure in the boiler.

A positive voltage into the "Boiler" integrator represented adding water, while a negative voltage represented water leaving as steam.
Adjusting "Water" voltage to cancel out the "Steam" voltage caused the Boiler integrator to hold a constant level.

A nearly identical circuit represented the boiler's water source, known as a Deaerator, except that the polarity was reversed. That way, the same positive voltage that "filled" the  boiler, "emptied" the Deaerator.  In turn, the source for the Deaerator's water, known as a "Hot Well", was also an integrator with the polarity reversed.

Put elements of the Difference Amplifier,
Summing Amplifier, and Integrator together
and you have the basic elements of a simulated feedwater circuit.  Adjusting the resistor and capacitor values alters the system's response, making it possible to mimic the response of the real world system you are modeling.  No, it is not sophisticated enough to respond in a non-linear fashion to simulate filling a round vessel, but it is good enough for many instructional applications.

    In the real world, water level in a boiler is critical, and any power plant would be equipped with high and low alarms.
Too low a water level, and the boiler could blow up.  Not a good thing.  Too high a water level and the boiler will spit water out
along with the steam.  A very bad thing for a modern turbine, or even an antique steam locomotive.
  Therefore, we equipped our simulator with alarms, too.  Here, the simple comparator circuit was ideal.
When the input is below a set level, the comparator will flip to -15 volts. Above that, and it will flip to +15 volts.  The alarm level is easily set with a variable resistor:
We added additional comparators to shut down the boiler in case the operator did not respond correctly to the situation.
   There was also an annunciator which sounded when an alarm went off.  This could be silenced by the operator pressing a Reset button, but the light for that alarm would stay lit until the condition was corrected.  It sounds simple to do, but how does one allow the annunciator to sound for additional alarms?  To solve this, I made a crude "One Shot" circuit consisting of a capacitor and diode. Each time an alarm sounded, a pulse of current flowed into the capacitor, just enough to latch the annunciator's relay.  Every alarm needed one of these "One Shots", and there were about 20 alarms. The parts count was growing rapidly.

The boiler we were simulating had a 3 step startup sequence.  First, the blowers are started to purge any fumes out of the combustion chamber. Next, the ignition pilot is lit.  Finally, with the pilot burning, fuel oil is added.

  Here, we used an integrator as a timer.
The integrator slowly ramped up the voltage to the 3 comparators, turning them on in the proper sequence and with the correct time delay.

The boiler was fairly sophisticated,  with forced and induced draft fans, and an adjustable fuel/air ratio.  The student could alter the above and get the poor combustion and furnace pressure alarms to go off, or even have the boiler shut down. Also, manually starting the boiler was possible, provided the student turned the fans on in the right sequence.

While the circuit examples I have shown appear deceptively simple,  there were a lot of them, and many with customized tweaks.  In addition, there were circuits to allow the Simulator to run in full automatic.  The student could simply request more or less "Electricity" from the Simulator's  "Generator" and watch it run itself, with feedwater pumps automatically adjusting flow and the boiler maintaining the proper steam pressure.  The student could  then initiate a failure, say by shutting off water to the Hot Well and then watch watch the whole thing shut down in sequence as the feedwater system went dry.
One circuit I was especially proud of was my steam valve. This one presented a problem in that there were two variables: the amount the valve was open and the pressure of the steam.  I wanted a valve with realistic operation and the tricks I used for the feedwater pumps wouldn't do.  I hit upon an idea that I thought was novel, using a combination of an ordinary lightbulb and a photoresistor. It worked great.  Interestingly, I found a similar circuit while looking for graphics for this blog.  See the Multiplier circuit below.  In their circuit, they used feedback to make the response linear.  I did not need that, in fact, the non-linear response of my circuit is more realistic.
However, as I recall, I found no such circuit back then and conceived of the idea on my own.

Add all of the circuits together and this is the result:
Impressive looking, isn't it?  Here is the final product.  Not a bad facsimile of the real thing:
There were some interesting experiences associated with building the Simulator.  We had the support of our instructor, who lined up technical advisers for us. One in particular was most helpful, but somewhat skeptical, for he was in the business of building customized professional simulators that matched a customer's real equipment precisely.   I'm not sure if he appreciated our simplified approach.  However, while he had behind the scenes sophistication,  we had great graphics and lots of blinking lights.  If there is one thing that impresses non-technical types, it is lots of blinking lights. Of course, our lights were not there just to dazzle, they provided the vital alarm indications.
   Our return trip with the nearly complete simulator was humorous, thanks to those blinking lights and great graphics. The humor was provided by our adviser's non-technical supervisor, who actually said to him "Why can't we make one like that?"  Poor fellow.  He was working with the latest in digital technology, programming in every system detail, while we had very rudimentary analog circuits lurking behind a panel with lots if blinking lights.  It made us feel good, however. And, our simulator looked great, don't you agree?
Epilogue:  The Simulator ran reliably for over 10 years as a teaching aid at Williamson.  Then one year, some students who did not bother to read the instruction book decided the Simulator was broken, when in reality they were not following the proper start-up sequence. I made the mistake of leaving a copy of the schematic so that students interested in electronics could understand it's operation.  Unfortunately, they used the schematic to try to "fix" it, and made a real mess.  I took it home, and tried to sort things out. Internally, it was a rat's nest of point-to-point wiring, a giant breadboard.  That was a good way for us to develop the circuits in a hurry, but having someone else go in there and cut wires made it impossible to fix.  In the end, that type of simulator's days were numbered anyway.  Programmable computer controls were fast replacing the traditional controls that the simulator represented.  Time and technology marches on.