| > Is it too late? I think not if we act now > Mikes Blogs > Plugging into the SUN
Plugging into the SUN |  | | | 7'dish delivers 1500W to pot of water |
In the 70's when we had to wait in line for gasoline, I saw first hand what happened when supply fell short of demand. I live at the end of the power line,and thanks to falling branches,ice storms and such, I have had to go without power for over a week more times than I can remember.
I sometimes reflect on the fact that in many places in todays world, the poor people are living their whole life without electricity, or any of the luxuries that we so depend on.
The modern world has become so dependent on this supply of energy that we find it difficult to see a world without it.
This blog will document and follow some of the solar and alt energy projects that I am working on.I hope to eventually replace the gasoline engines on all of my yard maintenance equipment, and convert as much of my energy needs to solar/electric.
The Boy Scout motto "Be Prepared" is a very good piece of advice for all of us.
Blog starts at the page bottom.
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Solar cookout in 20 degree weather |  | | | A solar cookout in Feburary |
It was the end of a cold but clear day, Feb 1st and after playing with some batteries for most of the day, it was time to eat. I set up the rotisserie and cooked some burgers. They were fully cooked in only a few minutes. It seems that even with sunlight filtered by trees and the late winter sky, the thing will cook a burger as fast as a microwave.
(Posted 2/3/2010 by mikey) |
Making a big solar panel |  | | | Bigger solar panel |
Good Buddy Paul Provost decided he was going to make a larger solar panel with the small Solar cells.
He started by making a larger version of my cell spacing template. He improved the design by drilling a hole in the middle of each cell area to allow a finger to poke through to unstick any cells that may adhere to the fixture.
He set up the array with 9 cells in each series string for 45V Open circuit and about 20V under load.
There are 18 strings with a diode on each, to yield about 1.5A.
The cells were laid face down on the fixture, and the wiring was attached. The rear expanded vinyl backing was laid over the cell rear after 4 dabs of silicone was deposited on each cell. When the silicone was set, the complete fixture cell and backing fixture is flipped over to remove the fixture and yield the cell /backing assembly.
A 1/2 " plywood back plate with the cell assembly is placed in the welded aluminum channel frame. The cell face is protected with Polycarbonate clear sheet,
The connections are brought to aplastic electrical box for termination.
Looks professional, and makes a rugged assembly.
(Posted 1/22/2010 by mikey) |
The 7 foot circle of sunlight moves to rear deck. |  | | | Solar cooker in new position |
I had a great time cooking with the big dish last summer.
I am not ready to sit out the winter without making some progress with my solar experiments.
As we head for January 2010, I decided it was time to start using the big dish on a daily basis, and to refine it so it has many uses.
The rear deck was built with 2X6 lumber so there should be no issues with ruggedness.
I used my electric telephone truck to move the dish from the front yard to the rear deck. The bucket on the truck has a remote control pod, so I was able to move and position the dish my self.
The controls and power PV panel were moved around to deal with the partial shade that the dish will see in the morning.
Not a fun job when it is 10 degrees with a 15 MPH wind.
A switch was added to that automatically rotates the dish to a convenient food loading/unloading position, and a battery connector that will allow 2 prius subpacks to power the system, and charge from the solar panel between moves.
I put my canning pot with about 4 quarts of water right from the tap on the holder, and started the test. The sun was behind slight haze, as I said earlier, it was 10 degrees with wind, and the thin walled steel pot was not insulated at all. Within 30 minutes the pot was boiling over. All with a 7 foot circle of sunlight.
(Posted 12/30/2009 by mikey) |
Wood burning art ? |  | | | Solar Art??? |
Now that the device is fully operational,it was time to see how it worked. The X-Y stage response was very quick, so I added some capacitors to the joystick potentiometers to slow down and smooth the motion.
The focal spot is a bit large for the small piece of wood that the stage can handle, but it is still possible to write and do some simple graphics.
Solar art???? Looks like I need to do some practicing, and make the thing accept multiple lenses, so I can draw with a finer spot.
Lots of fun, and a good demonstration of the servo amplifier. Amazing how much energy there is in a 1 foot circle of sunlight!
(Posted 11/9/2009 by mikey) |
Solar powered wood burner focus and lens assembly |  | | | focus assembly details |
I had purchased a 12" fresnel lens from Edmund Scientific about 30 years ago, for a tracking solar furnace that ran a small steam engine.
solar steam engine 1972
The old tracker had been stuffed in the attic and forgotten, so I decided that this lens was to be the biggest lens for the system. I fabricated an aluminum lens holder and used silicone caulk to hold the lens. The lens would need to be quickly focused up and down in order to draw with the assembly, but the 1.5 lb lens lifting against gravity proved to be a bit much for the motor to do quickly, and the current required to lift it was nearly at the limit for the servo amp and solar power source. Another issue was that the well balanced multitracker vertical axis would only remain balanced at one position in its 7" of travel, which made the vertical axis also draw a lot of current as the lens moved away from that balance point. I solved both issues by mounting a second linear stage on the other side of the lens mount arm. A steel block that weighed the same 1.5 lbs as the lens was mounted to this stage, and is driven by the other side of the drive cable, so as the lens moves out the weight moves in by the same amount. This configuration balanced the lens weight with the steel weight at any pointing angle from horizontal to straight up, so the drive motor only has to provide the motive force, and not have to lift any weight. The vertical axis of the tracker was able to be balanced with a fixed counter weight on the stage side. This keeps the vertical axis balanced no matter where you focus the lens.
(Posted 11/9/2009 by mikey) |
Solar powered wood burner X-Y stage |  | | | X-Y servo stage |
Now that I have the multitracker operational, I decided that it would be fun to use the new servo board in a different way to demonstrate how the same board that tracks the sun can also operate an X-Y servo stage. The servo amp when used in this way, requires a position command voltage,and position feedback voltage.
I dug through my extensive stuff pile, and found some chart recorder mechanisms that I had purchased at the MIT swap meet several years ago. The assemblies have a cable drive system that moves the pen holder, with a 1K linear position feedback pot. I was going to move a stage with a block of wood so the direct drive motors would not have enough torque to do the job, so I mounted gear motors to the assembly to generate sufficient torque to lift the stage.I mounted two pieces of G10 copper clad circuit board material to both pen holders as the actuator arms. A phenolic block with a notch in the rear for the two control arms became the moving stage that the block would be mounted to.
The command pot in my device is a joystick, but any pot will work.
The position feedback pot needs to raise its output voltage when the command voltage raises or the servo will shoot off to one end or the other, and stall the motor. Not a good thing, so make sure that the stage moves the right way and stops when it gets in sync with the joystick if it does not sync, reverse the motor leads so it goes the other way, and you should be good to go.
(Posted 11/9/2009 by mikey) |
multytracker 1 |  | | | multy tracker 1 |
The tracker works very well, and quickly find and will point at the sun.
Some devices I hope to mount on the tracker
1. 250 v solar panel(for charging the Insight HV pack.
2. Solar wood burning drawing device.
3. heliostat
(Posted 10/9/2009 by mikey) |
Multy purpose tracker 1 |  | | | IC tracker 1 |
I had to put one of the new boards to the test, so I built a rugged tracker that can have several devices mounted to it.
The base is a piece of plywood, and the horizontal drive is a gearmotor driving a large spur gear.
The spur gear is attached to the base, so the gearmotor rotates with the upper assembly by riding around the large fixed spur gear.
This system allows a strong bearing on the main horizontal axis, and does not expect the motor shaft to carry the assembly, it only drives it.
The vertical drive is built the same way, and is a large aluminum angle frame that the devices to track will attach to.
The sensor PC boards are mounted to the side of the frame, and can be easily adjusted if necessary.
The amplifier has lots of gain, so we must adjust the gains so the tracker accurately follows the sun, but not so much that it begins to mechanically oscilate.
I built up a custom solar panel that can output 650MA @ ~10-12VDC, which should easily power the well balanced device.
(Posted 10/8/2009 by mikey) |
Designing a simpler and lower cost solar tracking amplifier |  | | | New low cost dual solar tracker |
I have been using a dual H bridge solar tracker design for many years, but it has a lot of parts, is relatively cheap, but takes some time to build on a breadboard. I needed to make another tracker for a new small solar dish, and decided to take a new look at the circuit.
After some research I found a nice solution.
Since a single power supply is how I wanted to power the system, a full bridge servo amplifier which can source or sink current through the motor in either direction was a requirement. I found that a bridge tied load audio amplifier chip if dc connected rather than the ac coupling that it was designed for will do the job nicely.I built a prototype on a breadboard, and found that it worked as well as the much more complex and expensive discrete component version that I have been building, and only has a few support components, so it is both inexpensive and easy to build.
a schematic of the circuit:
IC dual solar tracker
After some further tweaking of the design, I will be offering the built and ready to use dual tracker system including the photo diode solar sensors as a product.
Buddy Paul Provost laid out the pc board so that the circuit could also be used as the 15W stereo amplifier that it was designed for by simply cutting two etches and adding some capacitors.
The circuit can also be used as a dual position feedback servo by using a feedback potentiometer geared to the motor output on the +input and a position command potentiometer on the - input.
The motor will turn and rotate the feedback potentiometer to the position commanded by the command potentiometer. The command can also be generated by a computer with a PWM or analog output.
The board is designed with the chip on one edge, so the chip can be attached to a heatsink or chassis. My first test with 1-2A draw showed minimal heating of the chip, so only a minimal heatsink is required unless the system is pushed to the 2A limit frequently.
As with any tracking system, mechanical design can make or break the system. The axis should have balanced loads so the servo does not need to continuously drive current into an axis just to hold position.
(Posted 10/7/2009 by mikey) |
No more throw away batteries please |  | | | Solar three NIMH cell charger |
I needed a flashlight, and like so many people, I bought some of those cool LED flashlights. I grabbed one out of my drawer, and the three AAA batteries were dead. I went to buy some AAA alkaline batteries and was shocked when I saw the price. I saw 4 NIMH rechargeable AAA's with a charger,that can be used 500 times and bought that instead.
The cost of ownership of a well maintained rechargeable NIMH AAA is many times less than the throwaway kind, and it reduces the amount of energy required to make the one use batteries and to dispose of the spent ones.
The only thing I did not like about the NIMH was the wall wart charger that will inevitably be forgotten and stay plugged in between the charges, so it becomes part of the background load of the electrical grid.My charger and millions more are just wasting valuable energy.
I looked at my cute 3.2V 85MA solar cells, and decided that a solar charger makes much more sense. The flashlights will run for quite a few hours on a full charge. The 800 MAH duracell NIMH cells can take the 40-85 MA from the panels for many hours and only get slightly warm,and they will be topped off and ready to use when you need it.
A piece of PVC sign board, some hotmelt, A diode for isolation, and some strips of brass and steel, and you have a solar NIMH charger for the three cell battery packs that are used in many of the flashlights. One pack is used while the other sits in a sunny window getting charged with the greenest energy we will ever have.The two panels are put in series with the diode, and the positive and negative solar leads are soldered right to the brass terminals.
No regulator should be required at the
C/10-C/20 rate that the panels max out at.That is only 1/2 watt, which the pack can easily dissipate. I will do some long term test to see how the cells hold up to a several day charge which will hold them at the full charge point.
(Posted 10/15/2008 by mikey) |
More improvements to the dish |  | | | further improvements |
Had a couple of batches of tomatoes to can, so while waiting for the water to boil, I welded up a solar panel mount, so the solar panel can be attached to the dish permanently. Since the simple servo is not smart enough to find the sun each morning, I can just rotate the solar panel so it gets power, and then get the tracker in the approximate direction for normal tracking and then it is good for the day.
I have been wearing dark sun glasses when using the dish,as the sun at the focus point is too bright to look at with unprotected eyes. I found a sheet of red LED filter lexan in my stock pile, so I made up two viewing filters, so the glasses are not required.
(Posted 9/19/2008 by mikey) |
canning season is here again |  | | | Dish third axis, FOCUS |
Sue picked a huge crop of cucumbers, and wanted to make some pickles.
We did the first batch of 7 quarts on the electric stove. The canning pot took a full hour to reach boiling, then 5 minutes at boil for a total of nearly 2KWh to preserve them.
I prepared the dish for canning so the subsequent batches could be processed by the sun, but did not want to deal with the fabric thermostat, so I added a focus adjuster. The focus system has to be strong enough to raise the heavy pot of jars and water, and my rule that I must be powered with the same 50W solar panel required some digging in my surplus motor box. I found a Pitman 19.5:1 gear ratio 24v motor, that did the job with power to spare. The lead screw was a surplus acme threaded rod with a single ball bearing on the bottom end, and a bronze acme nut at the top.
The parts were surplus from the polyscan bone density/thyroid scanner that I designed and built back in the 80's.
I got 6 inches of travel out of the focus, and made a new mount for the pot hanger to put the pot bottom just at the sharpest focus when at the bottom of travel. Once the pot starts to boil over, I adjust the focus by raising the pot reducing the solar energy. I was able to maintain a gentle boil without boiling over.
In theory this could be automated to maintain a fixed temperature. I processed 9 quarts of pickles this morning. Yummy and with no guilt as far as carbon production.
(Posted 8/26/2008 by mikey) |
Burgers are better |  | | | WOW is this thing a fast cooker |
Since I am not much of a fan of hot dogs,and I was getting hungry, I decided it was time to try some burgers. I added a 1/4" shaft off the bottom of the broom handle, with a small gear motor to turn it, I made a small bracket for the dish bottom,for the drive motor to sit in.I powered this motor with a second small solar panel, and have included an on off switch.
A top rotating bracket that fits the adjustable fork, and made a stainless steel wire basket for both sides of the forks.The rotisserie turns at about 30 RPM
WOW, I never saw a burger cook so fast. It was evenly cooked right through in just about 1 minute, with no burning. The center temp got to 150F. I like my burgers a bit more rare, so next time I will make them thicker, and cook only to 120F or so. No grill warm up time, zero carbon production during cooking, and a fully cooked burger in about a minute. Why are we using charcoal and gas????
The same basket and rotisserie should do steaks and chicken, so that will be my next test.It is so much fun cooking with the sun.
(Posted 8/21/2008 by mikey) |
Cooking some hotdogs |  | | | solar hotdogs |
Ok canning season is in the fall, and here we are mid summer, and we are using charcoal and propane to have some cookouts. I decided it was time to start using the big dish for some green cookouts.
I boiled the dogs first to cook them thoroughly, then I brown them in the intense heat before eating. It only takes 10-20 seconds to brown the dogs. Next,steaks and hamburgs.
(Posted 7/14/2008 by mikey) |
First zero carbon test drive |  | | | EV telephone truck is ready to get to work |
For the first test ride, I clamped on an amp meter, and took my first ride around the yard, up some hills, tried first, second, third gears. In first, the average current draw was in the 60-75A range, it climbed hills with no more than 150A, and it even started off in third gear from a stop.
I need amp and voltmeters before I get better data.
Don't need the 6:1, this configuration has more power than required for my around the yard moving of the machine.
The bucket has dual controls, one set in the bucket, a second on the end of a 20 foot cable so the boom can be used as a remote crane. The boom hydraulics run off a 36V golf cart motor. The 55V solar panel array will keep the battery's charged and ready to go.
It would be great to make a remote steering and motor control system in the bucket, so I could ride around up there. It would get pretty hairy with the boom at it's 25 foot level. The thing crawls at very low speed, so it would be possible in theory.
The hydraulic boom could let the solar array track the sun, bigger array?
Too many projects, not enough time.
For now,the EV telephone truck is ready to go to work.
(Posted 7/5/2008 by mikey) |
E-Tek motor drive installed |  | | | new motor mount with chain reducer |
Made a motor mount weldment and got it attached to the rest of the motor drive system.
A careful use of an angle iron and some clamps assured that we welded the motor bracket to the rest of the assembly with perfect chain alignment.
After tacking the parts in place, I had to remove the whole weldment to finish all the welds and check alignment. I used the 4:1 reduction,since the smaller 12 tooth sprocket which will yield a 6.6:1 reduction has not arrived yet.
I wired in the bucket hydraulics, and solar charging system, so my full electric solar recharged bucket truck is 100% operational YEA!
(Posted 7/4/2008 by mikey) |
New coupling shaft |  | | | new adapter shaft |
The big motor was removed, saw blade was disassembled from clutch plate. The clutch plate rivets were ground off, and the central torque plate was removed. A look through my stuff pile turned up a rusty cast steel pulley with a large enough diameter, and 1-1/8" bore. The shaft was turned down to make a press fit into the pulley, and the pulley was welded to the shaft.
The pulley was turned down with a precise cavity on the mounting end so the torque plate self centered when placed in the cavity. The 20 holes were used as guides for drilling and tapping 10-32 holes. Ready to mount the bearing.
(Posted 6/30/2008 by mikey) |
Not enough torque |  | | | 4:1 additional reduction |
After getting the electric drive components and battery connected, I found that the brakes and wheel drums were frozen, and the wheels could not rotate. I removed and freed up the rear brakes, and got the wheels to rotate freely. The front disk brakes were also frozen, so they were disassembled and made to work with much difficulty. The splitter valve for the brakes was broken, and the master cylinder had a vacuum leak.
When all was said and done. I routed the master cylinder output directly to the front drivers disk brake assembly (the only one that worked). The first electric run was disappointing, as the motor running with the max 400A that the controller is capable of, was just able to push the truck on flat grass. Once I tried to climb even a slight hill, it just gave up.
Based on the amp/torque curves for the CM77 motor, I should have been producing about 37 Ft Lbs. The CM77 output shaft is not designed for side loading, so it is not a good option for a chain based torque magnifying system.
I purchased an 80 tooth chain sprocket, a 20 tooth, and 12 tooth smaller sprocket and a bearing so I can make an additional chain speed reducer.
The e-tek motor running at 200A produces ~19 ft lbs, so if I use the 12 tooth drive sprocket with the 80 tooth large sprocket, which is a 6.6:1 ratio, I should be in the 125 Ft lb range which I estimate should be sufficient to move the 8,000 lb truck around my yard.
I may be able to walk faster than it will move, but thats fine for around the house.
Why is it never easy?
(Posted 6/2/2008 by mikey) |
All weather dish movers |  | | | New drive actuators for dish |
Taking a break from the bucket truck, I finally got the two 18" dish movers mounted on the big Solar furnace.
The vertical axis was easy, I used the old actuator arm on top, and welded up a simple bracket on the bottom.
The actuators have adjustable stops, which I adjusted so the travel was full range without hitting the stops. The horizontal axis was a bit more work, as the VW wheel, and stiffening webs only gave a narrow path for the actuator shaft to pass by. I wanted as near to 180 degrees of rotation as possible, so an offset bracket was made for the dish side so the actuator would clear the mounting shaft. It is a bit heavily loaded when at the two extremes of travel,because of steep actuation angle, but is smooth and strong every where else.Next the water proof box for the electronics.
(Posted 4/27/2008 by mikey) |
The controller |  | | | All wired up |
The next step was to mount the batteries and controller and wire it up. I bought some new batteries, as the 12 T105's that I had were pretty beat from to years of golf cart use. The batteries were mounted on an angle iron frame that was welded to the frame.
I got some beefy battery terminals, and invested in the correct crimping tool for the big 2/0 wire that was used for the high current wiring. $4.75 a foot for the welding cable makes one very careful to use as short a wire as possible. The throttle pot and linkage is always an expensive item, so I decided to try a simpler cheaper way. The truck throttle cable was fed through an aluminum bracket, and then to a spring to pull the cable out and lift the throttle pedal.
The travel of the pedal/ cable was limited by a small aluminum bracket so the cable travel is the same as the 5K slide pot travel. I found a piece of thin spring steel with a slotted end, that with a bit of sanding fit nicely into the slot in the slide pot actuator. The slide pot was moved to the end of travel, and the throttle switch adjusted to open when at the end of travel. The spring steel actuator was first held with zip ties, then taped to the throttle cable sleeve with black electrical tape, which is carefully coated with PVC pipe cement to make it permanent.
It works quite well considering how simply it is made. The first powered test showed a non linear response, and sure enough the pot was an audio taper rather than linear. I mounted the pot so the taper gave smooth low speed operation, and a fast ramp up in speed at the full throttle end. The worlds first log throttle.
(Posted 4/25/2008 by mikey) |
The mounting plate |  | | | Motor mounted and ready to go |
The broken terminal strip was replaced with a new one machined from a piece of linen phenolic that I had. I pressed in large brass nuts, then glued them in with epoxy. The next issue was the strange mounting system. The motor was designed to fit a cast iron mounting flange with a bayonet lock and keyed anti rotation section. I chose an easier to make 1/2 " aluminum plate, and a bayonet ring of just the right thickness so I had to tap it with a hammer to lock it in. A separate steel keyed block was made that bolts to the large aluminum mounting plate. The bell housing looked a bit weak to support the 90 lb motor, so I welded up a complete angle iron bracket to carry the weight.
I clamped the bell housing on my bridgeport table then indicated the round tranny locating hole on the bell housing to center the miller quill on the tranny mounting hole.Then I took the main motor mounting plate and with the indicator got that exactly concentric with the tranny hole. With the plate clamped to the bell housing I drilled two spring pin holes and drove in the spring pins to allow disassembly and re assembly with perfect alignment. I transfered the two 7/16-14 holes to the mounting plate and drilled clearance holes.
The final step was to determine the exact thickness spacer necessary to engage the clutch plate with the tranny spline with about 0.02" clearance between the two shafts.
With some help, the assembly was mounted. Next step battery holder.
(Posted 4/9/2008 by mikey) |
The coupling |  | | | Drive shaft is coupled to clutch disk |
The tranny has one size spline, and the motor had a slightly smaller spline, so rather than spend a lot of time and money trying to find an adapter, I decided to use the clutch plate which already mates to the tranny shaft, and adapt it to the motor output shaft, using a steel disk. While a 10" to 12" saw blade would do the same job, I found some larger blade blanks that I had been given by a friend, and decided to use that.I punched out 10 of the outer rivets on the clutch plates, opened the holes to the tap drill size for 1/4-28 screws.
I turned a snug fitting steel alignment shaft that fit on the ID of both the clutch disk spline and the saw blade ID. This forced the two disk to be centered on each other. I clamped the two disk together, and drilled the tap drill holes through the blade. The blade holes were tapped to 1/4-28, and the clutch disk holes were opened to 1/4". The motor output shaft was welded to the saw blade, and the clutch plate was screwed to the saw blade to make the final adapter. The assembly was spun in a lathe to confirm that it runs true. Now the delicate and critical final step of mounting the motor to the bell housing exactly concentric with the tranny output shaft. Both the tranny output shaft, and the motor output have some degree of shaft misalignment compensation which should help.
(Posted 3/31/2008 by mikey) |
The drive motor |  | | | The power plant?? |
This Truck is pretty heavy, and even in first gear, it takes some serious torque to move it. My first motor choice was the e-tek which is a PM motor, but after looking at the performance curves, it really would be pushing the e-tek to try and drive the truck.
Back in the 70's I got the bug to build an EV, and picked up a pretty beat 30V 400A 15 HP motor/generator from a surplus equipment company. This is a series wound motor that can take some serious power, so I decided I would use that instead. These motors have so much torque that the drive shaft can snap, so they use a torsion bar output shaft. The rear of the torsion shaft is driven by the rear female spline of the main motor shaft which is a tube.The output side of the motor has another external spline to drive the drive flange. The flange elongated slots engage the three raised post on the output end of the torsion shaft once the torque is high enough.A clever way to keep the output shaft from snapping under the high torque.
The drive spline will not be used on my coupling system so I cut it off with an air cut off wheel, since the shaft was too hard to cut with a bandsaw.
(Posted 3/31/2008 by mikey) |
Tranny support |  | | | mounting the tranny |
The tranny needs to be supported on the frame, so I bent a piece of 1/4" X 2" steel angle iron to the required angle to screw to the top 3 bell housing mounting screws, and terminate flush to the frame members.
I cut out two shorter angles, and screwed them to the tranny mounting angle at both ends. I welded a nut on the rear of the short angles so the 3/8-16 bolts would have a real nut to screw through.The two small angles were then welded to the frame. The extra drive shaft was cut off to keep the electric motor from needing a thick spacer when mounted to the remaining screws in the bell housing. The clutch plate will be my final drive attachment to the motor shaft, so I needed a disk to make the final connection to the drive motor. I had some circular saw blanks, and will see if I can make it work with a bit of machining and welding.
(Posted 3/28/2008 by mikey) |
Bucket truck kicks it's gas habit for good |  | | | EV bucket truck conversion 1 |
I picked up an old telephone truck some years ago, and have found it very useful for many things. Painting, cleaning gutters, lifting shingles to the roof for roofing, trimming branches, as a crane with my remote control. The Onan gas engine that ran the hydraulics for the lift ran dry one day and seized up, so I mounted a golf cart motor in its place and mounted 36V of batteries with a solar charger, converting the lift to full electric. It works great, always ready and charged. The truck has a big V 8 engine in it, and as you would expect with an engine that hardly ever runs, it is a major chore to get the V8 to run whenever I want to move it.In preparation for a lot of roof level projects that will be coming up on the to do list, I decided it was time to finish the job, and convert to full electric. No need for road travel, just need to move it around the house, so I figured I would pull out my spare E-tek motor and controller, and start there. Troy, and Dan came over and we got the gas guzzler out of the beast after a bit of wiggling.Now I need to support the tranny and motor, couple the e-tek to the motor, do some wiring, and hopefully I should be able to ride around the yard in first and reverse.
(Posted 3/23/2008 by mikey) |
solar cell adhesion test #1 |  | | | silicone adhesion test |
I grabbed a piece of the smashed front end of Bluebird 1, washed it with soap and water, then wiped it off with alcohol. I prepared the 4X3 array (4 in series X 3 strings)by laying them carefully on a piece of plastic. I tacked the corners with a dab of hot melt. Soldered the series jumpers with a small strain relief loop on each. taped over the soldered connections, and tacked down the ribbon output cable.
I will let this dry for a week before testing.
(Posted 2/26/2008 by mikey) |
Solar cells on my Insight ???? |  | | | 213 cells or 17.75 Watts on hood |
Ok here it is, the moment of decision that we all must face when trying to make progress.Do I ever expect this car to be brought back to stock condition again? Naaaa!
The 250 V (open circuit)panel that I built outputs 85ma of current at 180V with 56 of the mini solar panels.
The next step along the path is the integration of solar cells into the body of the Insight. The only way to put glass cells on a car body is to shock mount them so they can take some flex, and make damn sure that they will not blow off.The small 2.4" size of the mini panels allows them to somewhat follow the contour of the hood and roof.
The hood will hold 213 cells and output 17.75 watts.
The IMA pack can handle 250ma without damage. 56 cells will yield a solid 85ma at 180VDC.
3 parallel strings will yield 255ma so the hood alone
can take care of trickle charging the IMA battery.
The roof test will need to wait for a warmer day.
Aerodynamic pressures when traveling at 100 MPH can be very strong, and the cells had better not fly off.
Some interesting problems to solve, hopefully in a way that will not involve damage to the car????
Suggestions?
(Posted 2/20/2008 by mikey) |
Solar teaching toys |  | | | Solar teaching toys |
I have been invited to do a solar workshop at a local high school, so I have assembled and built several interesting solar powered devices.
The Solar Tesla coil is not finished yet.
More fun in the sun.
(Posted 1/8/2008 by mikey) |
Tracking the sun Big Time |  | | | Tracker Version 1 |
The big hurdle that many people have when thinking of converting your old big dish into a solar furnace, is how to make it follow the sun.
it is really pretty simple,especially if it is kept in the analog world. Never underestimate the lowly Op amp, and a few power transistors.
The sensor is something I invented 20 years ago, that is the magic in the self powered solar tracker below.
Two photo sensors are configured so the two detector outputs will cancel to zero V when both have equal angle/illumination from the sun.
Photo diodes or chips of solar cells work well as photo detectors. I set them at 45 degrees to each side of where I want the null to be. The ones I used on the big dish are set in epoxy putty.
The first drive system has the horizontal axis powered by a precision harmonic drive gear motor that is way too expensive for a dish,but was in my surplus motor box.The vertical axis with just a simple wench, is very balance sensitive.Any imbalance against gravity has to be constantly provided by the motor to hold a position. Weather protection for a chain is too difficult.
I found some nice C band big dish satellite movers for $39, and they are waterproof and since they are an acme screw drive, do not need to provide much holding force even with a big weight imbalance.
The new motors will be put on the system in the spring.
A schematic of the basic tracker is available on the downloads page:Simple Tracker schematic
The photo detectors I used were osram BPW34FA which are available from digikey
photo sensors
(Posted 11/1/2007 by mikey) |
Solar tracking with no electronics" Solar Puppet" |  | | | Solar powered solar tracker no electronics |
Many years ago I built a small device that follows the sun without any electronics. With my new found solar panels and some nice precision gear motors I built a cute completely solar powered devise that looks to the best source of green energy we will ever have, the sun. The baby's eyes look at it's generations best hope for a kind world.
The dual cubes are set up so that the opposing solar panels current cancels when they both are evenly illuminated by the sun.The resultant voltage is zero. When the sun moves to the west, the panel on the west side gets more direct sun, and the east side gets less sun.The increased current on the west side brings the voltage across the cells up with the polarity of the west panel. This drives the motor to the west until a new null is located. The vertical axis works the same.
The shades amplify this unbalancing effect near the null point for more accurate tracking.
When you bend over to read the sign, your shadow makes the device look away. When you move again so it gets full sun, it leaps back quickly to point directly to the sun. Almost seems alive. A cool toy and science project.
The two solar panels on the back assure 360 degree recovery. A simpler dual panel tracker works just fine except for when the sun is behind both panels.
I discovered another cool use for the device. A solar puppet. I stand at a distance, and using my hand/fingers to cause a shadow on either the horizontal or vertical cells, I can make the device shake up and down for a yes, and left to right for a no.
Is solar energy our best source of green energy? I shade the vertical cells to make the eyes go up and down for a "YES". Do we have a lot of time to switch to alt energy sources? A shading of the horizontal cells makes the eyes move left and right to say "NO"
(Posted 9/26/2007 by mikey) |
Second test |  | | | Testing and Tweaking |
Sue got three more quart jars of tomatoes ready, and I ran my first test with thermostat.
I still had the top blow off problem, where internal steam was generated and the caps were loosened. I realized that the very hot surface of the pot, and the small amount of water between the jar bottoms and the pot bottom, were allowing the water directly under the jars to boil first, and therefore the jars were heating the water bath, and were reaching boiling before the rest of the pot. I had saved a circular aluminum shelf from the bottom of an old pressure cooker, and will use that next time, and believe that should solve the internal pressure issues.
I could clearly hear the blup blup of the water boiling,and to my surprise, I only needed a small part of the dish to keep it boiling.
This thing is asking for a steam pressure boiler. Bet I could get some serious pressures going.
I did some energy calculations.
I put 7 quarts of water from the tap at 60F into the pot. Seven quarts weighs 14.6 lbs. I heated the water and the pot from 60F to full boil in about 30 minutes. That temperature change of 152F took 152 BTU X the 14.6 lbs or 2219 BTU/ half hour.
1KW generates 3415 BTU/ hour, so my 4438 BTU per hour dish is putting 1.3KW into the water. That was with the folding thermostat opened but still blocking some of the dish, and the mirrors needing a cleaning.
Can't wait to see what the 10 foot dish will do.
Click for some ideas on how you can make your own
Making small solar concentrator
(Posted 9/23/2007 by mikey) |
Canning pot |  | | | The boiler |
Sue usually canned 7 quarts at a time, but I did not like the idea of suspending the weight of several gallons of boiling water in mid air on a sometimes twitchy dish. I searched all the stores, and finally found a Martha Stewart pot at Kmart that fit three quart jars perfectly, with just a bit of room. I notched the handles so the low CG would always keep the pot upright. I glued a cork gasket on the upper lip using silicone caulking (good for 450F). A vent tube and thermometer port, with two springs to hold on the cover, and I was ready to go.
(Posted 9/23/2007 by mikey) |
The sun is dropping 1KW/SQ meter |  | | | Solar thermostat |
To put that into perspective, your microwave oven uses about 600-1kw when running.
I put the mirrors and built the stand for this old radar dish in the early 80's but never got the thing to do any useful energy gathering until this week.
Sue loves organically grown veggies, and has canned pickles, tomatoes, and beans for many years. When I see her heating the large canning pot to a boil and holding it there for nearly a full hour start to finish, It hurts me to think that the free veggies have sucked so many electrical watts to preserve them. I finally got a working canning system going.
The dish needed a tracking system, and a way to hold the pot so it was properly heated at any solar position.
The first run of the system showed me that I had way too much power.The cover had blown out on one of the jars, as the boiling was so intense, as to bring the tomatoes to the boiling point, and turn the internal water to steam. I needed a thermostat.
The first approach that came to mind was to move the container to a different point in the focus, but I did not want to have to play with the tracking system calibration and wanted to have the system self operating.
I thought of how oriental fans fold up and spread out, and built a rather crude and rude dual fan one for each side of the dish. The "Thermostat" is part open in photo.
(Posted 9/23/2007 by mikey) |
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