DIY Raised Gardens in NY with very little land

Last year I started a small raised garden.  I started the plants indoors in March and then moved them outdoors into two raised beds made out of 2 by 6's.  Each one was about 8 feet by 3 feet in size.

Last year I used egg cartons to start the plants, they were way too small!  This year I used mostly yogurt containers to start my plants.  The plants seem to thrive in these yogurt containers.  I poked a hole in the bottom of them to help prevent over-watering.  I also bought some plant starter kits.  They were a total flop, only about 8 out of 36 plants grew!  All of the seeds in the yogurt containers grew.  The problem with the starter trays is that the "dirt" must be pointed up before the water is added. Otherwise the dirt expands crosswise and is under too much pressure for the plants to grow.  Also the potting soil that was used in the yogurt containers is far more effective in starting plants.

Here is a picture of them after about a month.  The cardboard type of seed starters are better than the yogurt containers in the long run.  They are ready to go in the ground, half of them are already planted.

Here is what my garden looked like last year when everything was first planted outside.  The peas are in the front row.

This is an update - the garden in June.

This is what the garden looked like at the end of last summer.  The peas have died and cucumber and zucchini have taken over.

Another secret to gardening is to use rain water.  I have a large plastic trash can that fills with rain water to keep the garden watered.  If you must use tap water then let it sit overnight first.

DIY Arduino CNC Projects for 3D printing, engraving, etc.

I am working on making my own Arduino powered CNC 3D printer and light duty milling machine.  It started off as just some pieces of Plexiglas and parts salvaged from some old scanners and printers.  I will likely write my next book about building your own "Arduino CNC Projects".

I added some wood for the main platform and used an old LED sign board to hold the electronics.  The Robo raptor is jealous that I am no longer playing with him.

I bought a ball screw drive for the Z axis on eBay and figured out how to mount it.  The X and Y axis were belt driven but kept binding up and had too much play in them.

Next I upgraded to NEMA 23 stepper motors and ball screw drives for the X and Y axis.  Now it runs much smoother.

The mechanical part is just about done, but the electronics will need a lot of work before it starts running. Currently the Arduino is driving the steppers through some L298 driver IC's.

Here is the electrical so far.  I have built a L297 interface board but it is still not working properly.

Here is a link to the video on youtube: https://www.youtube.com/watch?v=RL-55GaYAvs

Projectors for Africa Part 2

Years ago I was in Africa with my brother.  We were setting up a video Bible school and we purchased a large TV to show the video's on.  However the guy using the TV only had a bicycle to haul it around with.  I thought "If only I could send over some Projectors!"  That year we started sending video projectors to Africa.

Last year I refurbished over 20 Video projectors for use in Africa and in the Philippines.  This year I have already purchased over a dozen used projectors that need to be refurbished.  That included cleaning and adding a new air filter.

My brother just took a load of projectors over to Africa and sent back these pictures of happy pastors.  He includes a Video Bible School and some of his teaching Video's.

We need DVD players, power cables, VGA cables and A/V cables.  If you have any you want to donate let me know.

RAWNY Mini Hamfest in Tonawanda NY

Last night I attended the RAWNY mini Hamfest in Tonawanda NY.  It was actually fairly well attended and I got rid of at least 3 boxes of stuff as well as sold about 5 or 6 books.

Here is a picture showing the awarding of the prizes.

Here is my table.  Someone said that i had the cleanest table there.  I had all my free junk hidden underneath it!

I might have brought home almost as much stuff as I took.  I collected several 12 volt 5 amp AC adapters for free.  I purchased many VGA cables for $3 each.  I even picked up something that I did not know what it was.  I think it might be a serial port RS-232 to Coax converter.

Arduino powered Roomba Robot

I have taken a iRobot Roomba vacuum cleaner apart and made an Arduino Powered robot out of it.  There is a serial port on the Roomba, but mine was dead so I wanted to do a complete rebuild.  I am using a L298 motor controller IC.  The Arduino is on the back right corner in the picture below.

At first I was just interested in how much power the Roomba has.  It easily got around with about 20 pounds of added weight and could push chairs out of its way.  My long term goal is to make a life sized robo-raptor and this would make a nice foot.  I have videos of a 2 foot long robo-raptor also under control of an Arduino.

Here are the videos:
http://www.youtube.com/watch?v=6Kd9IM1UDb8

http://www.youtube.com/watch?v=f9-WJ3wGICo

Arduino powered Robo-Raptor

I have been working on rebuilding a Robo Raptor to be controlled by an Arduino.  It is a key project in my latest book "Arduino Robotics Projects" available on Amazon.

Here is a link to the video on YouTube:
http://youtu.be/O8E3QBfjXO0

Here is a picture of the Arduino and motor control shield attached to the robo raptor:

Here is a picture taken from the video of it in demo mode:

After that picture was taken I managed to get it working on its batteries.

Here is the code for the demo.

// Robo-Raptor Demo

// demonstrates several actions the robo raptor can take.

// Written December 2013 by Bob Davis

#include AFMotor.h

#include Servo.h

// create servo object to control a servo 

Servo myservo;

// mororr moves the right leg

// create motor #2, 64KHz pwm

AF_DCMotor motorr(2, MOTOR12_64KHZ);

// motorl moves the left leg

// create motor #4, 64KHz pwm

AF_DCMotor motorl(4, MOTOR12_64KHZ);

// motorw wiggles the tail, head moves too

// create motor #1, 64KHz pwm

AF_DCMotor motorw(1, MOTOR12_64KHZ);

// motorh moves the head up and down

// create motor #3, 64KHz pwm

AF_DCMotor motorh(3, MOTOR12_64KHZ);

char INBYTE;

// Set A6 as an output pin for speaker

int SpkrPin = 19;

int roar;

void setup() {

  motorr.setSpeed(255);     // set the speed to 255/255

  motorl.setSpeed(255);     // set the speed to 255/255

  motorw.setSpeed(255);     // set the speed to 255/255

  motorh.setSpeed(255);     // set the speed to 255/255

  pinMode(SpkrPin, OUTPUT);

  // The servo is on pin 9 

  myservo.attach(9); 

}

void loop() {

  // Sequence of Motor control commands:

  // wait for tail switch to get started

  // wiggle tail back and forth

  // raise and lower head three times

  // take a few steps walking forward

  // make a roaring sound 

  // Wait for tail switch to start demo

  while (analogRead(A0) != '0'){}

  // wiggle tail

  motorw.run(BACKWARD);    // wiggle right

  delay(200);  // pause

  motorw.run(RELEASE);     // stopped

  delay(300);

  motorw.run(FORWARD);     // wiggle left

  delay(200);  // pause

  motorw.run(RELEASE);     // stopped

  delay(300);

  motorw.run(BACKWARD);    // wiggle right

  delay(200);  // pause

  motorw.run(RELEASE);     // stopped

  delay(300);

  motorw.run(FORWARD);     // wiggle left

  delay(200);  // pause

  motorw.run(RELEASE);     // stopped

  delay(300);

  motorw.run(BACKWARD);    // wiggle right

  delay(200);  // pause

  motorw.run(RELEASE);     // stopped

  delay(300);

  motorw.run(FORWARD);     // wiggle left

  delay(200);  // pause

  motorw.run(RELEASE);     // stopped

  delay(300);

  // raise and lower head

  motorh.run(FORWARD);     // raise head

  delay(300);  // pause

  motorh.run(BACKWARD);    // lower head

  delay(300);  // pause

  motorh.run(RELEASE);     // stopped

  delay(500);

  motorh.run(FORWARD);     // raise head

  delay(300);  // pause

  motorh.run(BACKWARD);    // lower head

  delay(300);  // pause

  motorh.run(RELEASE);     // stopped

  delay(500);

  motorh.run(FORWARD);     // raise head

  delay(300);  // pause

  motorh.run(BACKWARD);    // lower head

  delay(300);  // pause

  motorh.run(RELEASE);     // stopped

  delay(500);

   

  // walk straight forward

  motorr.run(FORWARD);     // right foot forward

  delay(300);  // pause

  motorr.run(BACKWARD);    // right foot backward

  delay(300);  // pause

  motorr.run(RELEASE);     // stop right foot

  delay(300);  // pause

  motorl.run(FORWARD);     // left foot forward

  delay(300);  // pause

  motorl.run(BACKWARD);    // left foot backward

  delay(300);  // pause

  motorl.run(RELEASE);     // stop left foot

  delay(300);  // pause

  motorr.run(FORWARD);     // right foot forward

  delay(300);  // pause

  motorr.run(BACKWARD);    // right foot backward

  delay(300);  // pause

  motorr.run(RELEASE);     // stop right foot

  delay(300);  // pause

  motorl.run(FORWARD);     // left foot forward

  delay(300);  // pause

  motorl.run(BACKWARD);    // left foot backward

  delay(300);  // pause

  motorl.run(RELEASE);     // stop left foot

  delay(300);  // pause

  motorr.run(FORWARD);     // right foot forward

  delay(300);  // pause

  motorr.run(BACKWARD);    // right foot backward

  delay(300);  // pause

  motorr.run(RELEASE);     // stop right foot

  delay(300);  // pause

  motorl.run(FORWARD);     // left foot forward

  delay(300);  // pause

  motorl.run(BACKWARD);    // left foot backward

  delay(300);  // pause

  motorl.run(RELEASE);     // stop left foot

  delay(300);  // pause

  //open mouth

  myservo.write(0); 

  delay(300);

  // roar

  for (roar=200; roar > 0; roar--) {

    digitalWrite(SpkrPin, HIGH);   // sets the speaker on

    delay(random(10));        // waits for a fraction of a second

    digitalWrite(SpkrPin, LOW);    // sets the speaker off

    delay(random(10));        // waits for a fraction of a second

  }

  //close mouth

  myservo.write(90); 

  delay(300);

}

Toshiba L645 Disassembly and fan cleaning.

I recently had a Toshiba L645 come in for a power jack replacement and a fan cleaning.  The power jack comes as a cable assembly that has to be ordered to fit the laptop.  There are some tricks to getting it apart.  There are screws in the battery compartment holding the trim that covers the screws that holds in the keyboard.  There is a screw inside of the memory compartment that holds the CD ROM drive in, and once it is removed there is a screw located above where the drive was.

1 – Remove the 12 bottom screws.

2 – Remove the 2 screws for the hard drive drawer, and remove hard drive.

3 – Remove the battery and remove 5 screws located below the battery.

            The two smaller screws hold the keyboard bezel cover in place.

4 – Remove three keyboard bezel, the screws above the keyboard, and the keyboard.

5 – Remove the seven screws under the keyboard, the right two are shorter.

6 – Remove the 3 screws and the memory cover, inside there is the CD ROM screw.

7 – Remove the CD-ROM drive and the screw hidden above it.

8 – Unscrew and/or unplug the wireless network card.

9 – Unplug the mouse, speakers and power switch, remove the top cover of the laptop.

10 – Un-tape and unplug the video cable, and the USB/VGA jack cable.

11 – Remove three motherboard screws marked with white arrows, and one fan screw.

12 – Remove motherboard with the fan assembly.

13 – Remove 4 super tiny screws and remove the fan cover to clean the fan.

As you can see in the picture the fan was fairly clogged with dust.  A small paint brush can remove the dust.  The picture quality is not that great, I was using my cell phone camera.

When I reassembled it the screen did not work.  The screen plug looked like it was plugged in but it was not inserted properly.  You might want to mark the tape that holds it in with a marker prior to unplugging it so you know if you have it back together correctly.

This picture shows the 5 screws that are located below the battery.  Two of them hold the cover that gives access to the keyboard screws.

Three color RGB 8x8 LED Array

I recently obtained an 8 by 8 three color RGB LED array to play with.  I set it up with three 74595 shift registers and an arduino.  It was really easy to get it working.  Here is a link to the company that sells the LED array.
http://www.icstation.com



Here is the video of it working on youtube:
http://youtu.be/wdONGo4giHs

I might eventually post the code but it follows my code that was used for the two color 8x8 arrays that is found in my book "Arduino LED Projects".

Here is a blue smiley face (with white hair) using the RGB array:

Here is a red, green, and blue flag using the RGB array:

I am contemplating making a larger RGB sign so I can do scrolling text in full color.
This is the schematic diagram:

Remote selection relay design

We recently had an application where we needed to remotely switch between two RF amplifiers.  I used Google and searched to find a solution to no avail.  So I am posting this to save the next person a lot of time.

All we had available was the single transmission line coming from the RF amplifier.  We were sending DC up the transmission line to power the amplifier.  Because of a lightning issue we could not use anything “solid state” to create a working solution.  The first thing that comes to mind is reversing the 12 VDC to switch amplifiers, but then the amplifiers negative input was fastened to ground so that cannot be done. 

However there are some solutions to switching between the two amplifiers by pulsing the power to the remote amplifier.  All we can do is interrupt the power for a fraction of a second to switch between the amplifiers.

One solution is to use an “alternating” “impulse” or “bistable” relay.  The most common such relay is the S89R11DAC1-12. It is available from all major vendors.   The biggest problem with that relay is that it draws half an amp of power.   That might be solved by putting a capacitor between the power source and the relay so that the relay is only activated for a few seconds when the power is turned on or when it is turned off then back on.  It is also a rather large relay and it is not socketed for easy replacement.  Here is a picture of what that relay looks like.

Solution number two is to use what is called a magnetic latching relay.  These relays have two coils, one to turn it on and one to turn it off.  A capacitor in series with the relay creates a pulse that either turns the relay on or turns the relay off depending on what coil is selected.  There are several kinds of these magnetic latching relays that are available.  Model number 755XBXCD-12D has a round base and 785XBXCD-12D has a square base.  Here is a possible, untested, schematic.

The next solution is to use a conventional relay but use a capacitor to detect how long the power was off.  If the power has been off for a long time then the capacitor will be discharged.  When power comes back on the capacitor is a “short” thus delivering 12 volts to the relay.  If the power was only off for less than a second, then the capacitor is still charged and the relay only gets about three volts.  That is not enough voltage to turn the relay on.  The 12 volt relay I tested had a 150 ohm coil and required 9 volts to turn on, but it will stay on all the way down to three volts.  Hence the relay will be turned on or off depending on how long the power was off.  Here is the schematic; it was tested to work with a power supply of 9 volts all the way up to 16 volts:

A brief history of health insurance - why obamacare is a failure

A brief history of health insurance – or why some of us knew that obamacare would be a flop.

**This is my personal opinion and is full of sarcasm, it is not meant to be entirely accurate**

Many years ago, most people did not have insurance.  However, back then there were lots of “nonprofit” hospitals that would gladly take anyone without insurance.  When my first two children were born we paid the hospital $100 a month for 10 months to cover all of the expenses.  The money went directly to the hospital or doctors, there were no middlemen.  Eventually those “nonprofit” hospitals were bought out and bulldozed.  Hospitals are now in the business of making money.

Then after that change, there was what is called “Major medical” insurance.  It cost our employer about $1000 a year and it covered everything medical that totaled over $2000.  We kept all of the paperwork ourselves and then submitted it at the end of the year.  Our insurance company then sent us a check for everything that totaled over $2000.  We then used that money to cover the medical expenses for the next year. 

Then disaster struck.  Our wonderful government thought that it would fix the “problems” with health insurance.  They passed laws that invented what is called an “HMO”.  HMO insurance included “Free” physicals and many other “free” things because, as we all well know, if you see the doctor for free you will not get sick and hence you will save a lot of money.  HMO’s also required that the primary care doctor would do all of the paperwork so he had to hire two or three secretaries just to process all of that paperwork.  HMO’s would save money because the doctor would detect problems earlier and you would not get as sick.  OK, maybe the premiums would go up a little because someone had to pay for all of the secretaries to process the paperwork and someone had to pay for all of those “free” physicals, etc.  Insurance went from $1000 a year to $10,000 a year.  Thanks to the US government for figuring out how to save us money.  As a result many people were no longer insured.

Then along comes more help from the “experts” on saving money.   Yes ObamaScare to the rescue!  His idea was that if those who were well paid a little [lot] more they could cover the expenses of those who were sick.  He also eliminated being refused insurance because of “preexisting” conditions.  He also included coverage for a lot of things like abortions and sex changes.  Of course someone has to pay for all of those new extra benefits.  On top of that, if you had insurance that did not include all of the new extra benefits, it has to be cancelled.  So as a result about 1/2 to 3/4 of those with insurance will find that their insurance is now cancelled.  However they will not be able to afford the increased premiums, to pay for those that are already sick, so in the end as much as 1/2 or more of the population will be left without any health insurance.

On top of that there is the now delayed “Employer Mandate”.  Any company with more than a few employees is required to give “free” health care insurance to all of its full time employees.  The solution is simple, make them “part time” employees.  This led to massive job reductions and that led the “Employer Mandate” being delayed until after the election.    

Now if we were to go back to directly paying the doctors we could cut the cost in half because all middle men (insurance companies) do is increase the cost of seeing your doctor.  Remember ObamaScare is not medical coverage, it is health insurance, there is a huge difference there.

Common Radio Frequency Questions - RF FAQ

Radio Frequency FAQ’s

I now work for a company called ComProd Communications.  You can find us at www.comprodcom.com    We specialize in Creating RF Solutions.  There are several questions that we get asked a lot.  Here are some of the most common questions.

My antenna came with a ground plane; do I need to use it?

The ground plane is a critical part of any antenna system.  It has both a minimum size as in length and width, as well as a specific distance that it has to be from the antenna.  If you have to replace it for some reason the replacement but be larger in size as far as length and width, and it must be the exact same distance from the antenna!  The distance is critical because the reflected signal has to be in phase with the signal emitted from the antenna.  Changing the distance will cause canceling of the output of the antenna.  Making it smaller will affect the impedance of the antenna as the amount of reflected signal will vary over the length of the antenna.

Why has the cost of Combiners gone up while the cost of transmitters and receivers has gone down?

As transmitters and receivers have gotten cheaper their sensitivity and selectivity has gone down.  If the combiner does not remove unwanted frequencies then the receivers will be overloaded in their front end.  Let’s say we have a transistor RF amplifier running on 12 volts.  If it has an input signal that produces an output that is over 12 volts peak to peak it will turn it into a square wave and produce tons of harmonics.  This will totally hide the frequency that you want to receive.  The combiner must remove the unwanted frequency from both the transmitter and the receiver in order for the receiver to work correctly. 

Are antennas best stacked vertically or horizontally?

Back in the early days of audio it was common to see lots of speakers positioned horizontally across the front of the stage.  The concept was to have a speaker aimed at everyone in the audience.   At some point engineers started pointing out that if you stack the speakers one on top of the other (Vertically) you get much better sound dispersion.  Although this does not look correct to the eyes, time and experience has proven that it works.  Now most bands use vertically stacked speakers.  The same is true with antennas.  Mounting antennas one above the other seems like it would be sending signals out into space, but instead it concentrates the beam horizontally.

Why do we need separate receive and transmit antennas?

Transmitters emit some signals at unwanted frequencies, usually close to their primary broadcast frequency.  These unwanted frequencies are rapidly reduced in strength as you move away from the transmitting antenna.  However these unwanted signals can easily interfere with receivers that are operating on nearby frequencies.  If you have a separate transmit and receive antenna this problem can be drastically reduced.  Otherwise the frequency of the receiver needs to be removed from the transmitters output as well as the frequency of the transmitter must be removed from the receivers input.

Replacing the stove vent hood

Replacing the stove vent hood should be an easy thing to do.  However I wanted it to vent inside in the winter and then vent outside in the summer.  I also had to adapt from the new exhaust size of 7 inches to the old pipe size of 5 inches.  I used a 7 inch to 6 inch adapter, then a 6 inch to 5 inch adapter.  Then to shut off the external vent during the winter I added a 6 inch flapper.  I had to cut off the old 5 inch pipe to make room for the new adapters.  Then I had to cut 1 inch slots in the old 5 inch pipe to get the new adapter to fit inside of it.

I also had to cut bigger holes in the cupboard to fit the new 7 inch diameter pipe adapter.  Then I had to cut it two more times to make room for everything to fit together.

Then I had to assemble the adapters with the closer/flapper and test it all out prior to installation.

This is what it looked like once assembled in the cupboard.  The hole in the top of the cupboard is now closed off with duct tape.  Cutting a piece of thin plywood to fit using a cardboard model would have looked better.

I forgot a picture of what it all looks like once assembled, hopefully I will include that soon.

Dodge Stratus Fan speed control

My wife's Dodge Stratus developed a second heat control problem.  The heater fan only worked on high.  This has happened to me before on other vehicles but I could not locate the speed control assembly.  Someone told me to check under the passengers side dash near the blower motor.  It is almost impossible to see it there, without a mirror, but I was able to get a picture of it.  First remove the flimsy nut that holds on the cover, then remove the cover, and then it is visible.  Remove the two mounting screws and turn it around so you can see the back side to disconnect the electrical wires.  It requires releasing two catches to be disconnected.

The fan speed control is the light gray thing on the lower right side of this picture.

Ford Windstar Heat Control Actuator problem

The heat stopped working in my van this spring.  That was not a serious problem for most of the summer.  Fall is here and naturally I had to fix it.  The symptom is a "clunking" noise from behind the radio/climate control.  So I removed the radio/climate control assembly by removing the two screws above the ash tray/cup holder.  I had already broken off the other two screws that were at the top of the radio/heat control section when I replaced the radio.  Way back behind everything was a white box where the noise was coming from.  I started removing the box and I dropped my nut driver down inside there somewhere.  Next I removed the two screws on each side of the bottom assembly that has the tilt out CD holder, and removed it.  Then I retrieved my nut driver and went back to work.

Here is a picture of the top of the heat control door opener as is seen behind the radio.  There are two screws to remove.

Next there is another two screws to remove at the bottom behind the climate control section.

Now if you are lucky you can remove the motor actuator and if you are like me you can take it apart to see why it makes that noise.  The smaller black gear is missing several teeth.

A replacement motorized heater door opener is $28 on eBay or about $10 more at auto parts stores. It is officially called the "Heating and AC Vent Door Actuator".  You can also replace it with a piece of copper wire to hold the door open, but that does not hold up and if you do it I guarantee it will be 90 degrees outside the next day and you will be stuck for 30 minutes in traffic on I-90.  I speak from experience!

DDS Function Signal Generator Sine Square Sawtooth Triangle

I recently purchased a function/signal generator on eBay.  I bought it because my computer based signal generator was limited to a top frequency of only 20KHz and I wanted to go a little higher.  I also wanted a signal generator for my "Fringe Electronic Devices" book.  I wanted to write about the signal generator for people who do not have, or do not know how to use, a computer based frequency generator.  I was delighted that this signal generator works great, and that the very limited instructions do in fact cover what is needed to get it to work.

I added spacers under the bottom two corners of the LCD to hold it in place and hot melt glued the function generator into a 3.25 inch by 4.25 inch project box.  I had to trim the bottom edge of the project box as the circuit board was just a little bit too big to fit otherwise.  A box that was 4 inches by 3.25 inches would have been a better fit.

The function generator will run on a 9V AC adapter or on a 9 volt battery with no problems.  What the signal generator is equivalent to is an Arduino with a resistor ladder based analog to digital converter.  Then there is an Op amp buffer amplifier to drive the output jacks.  I was able to find a schematic of an earlier version of the device.

My function generator did not come with a back-lit LCD so I swapped another one in.  It is a standard 1602 LCD display.  At first it did not work at all!  The first problem is a 50 ohm resistor above the LCD jack that needs to be soldered in for the back-light.  The second problem is that the LCD contrast trimmer is located underneath the LCD.  You have to play with it to get the right setting.  I was tempted to unsolder the trimmers single pin, bend it up on the other two pins and solder a jumper from the single pin to the circuit board.  That way you could adjust the trimmer while watching the LCD to see if it is the best setting.

Here is what comes with the function generator, I fixed up the English to make it more readable.

Specifications:
• Operating voltage: DC9-12V
• DDS frequency range: 1HZ-65534Hz.
• High-speed frequency (HS) output up to 8MHz;
• DDS signal amplitude and the offset amount can be adjusted separately by two potentiometers.
• DDS signals: sine wave, square wave, sawtooth, reverse sawtooth, triangle wave, ECG wave.
• 1602 LCD menu.
• Intuitive keyboard.
• Section rate steps: 1,10,100,1000,10000 Hz.
(How fast it steps when you push the right and left frequency up/down buttons)
• The power automatically restores the settings that were used the last time.
• Offset range: 0.5V pp to 5V pp
• Amplitude amount: 0.5V pp to 14V pp

Key Functions:
The UP button selects the waveform
The DOWN button selects the waveform
The LEFT button decreases the frequency
The RIGHT button increases the frequency
The START / STOP button turns the output waveform on and off
(In the off state, the "left "and "right" keys set the output frequency.  The middle button starts and stops the selected waveform) 

"UP" output waveform selection order:
High Speed = Use the high frequency output
Noise Random = random noise output
Freq Step = Size of steps
ECG = electrocardiogram wave
Rev Sawtooth = reverse sawtooth
SawTooth = sawtooth
Triangle = triangle wave
Square = square wave
Sine

This picture is what it looks like without the LCD.

Projectors for Africa

A few years ago I purchased a bunch of projectors and sent them over to pastors in Africa.  Recently a pastor has been asking me for some more projectors.  So I went on eBay, looked around, and bought eight of them for $160.  That is $20 per projector.  They are Epson EMP-S3's.  The catch is that they all have around 2000 hours on their lamps so they need new lamps that cost at least $50 each.  If anyone wants to donate to this cause it would be greatly appreciated. 

Epson EMP S3 Projectors

Someone suggested that I try to retrofit them with LED's instead.  Well the high intensity LED's are almost as expensive as the 170 watt lamps so the conversion would not save much.  But LED's sure would last a lot longer than 2000 hours.  There are some 10 watt LED's that put out about 1000 lumens at 12 volts.  Those LED's might just do the trick.  I have ordered some to give it a try.

Epson EMP S3 Projectors

The projectors arrived and almost all of them worked.  Two of them needed new lamps.  One would not start at all and one only sometimes started.  The lamp hours on most of them are likely bogus, they are running around 1000 lumens and that is typical of a lamp with more than 2000 hours on it.   The biggest problem I am facing is the air filters.  The projector filters are completely clogged and if you try to wash them out they disintegrate into nothing.  Someone on eBay is charging $20 for a replacement filter but you can buy several feet of filter material at WallMart for $1 and make your own replacement filters.
   

Epson EMP S3 Projector filters

Just cut the filter material to the right size, then glue it along the edges.  It is a tight fit to get it into the projectors, but if you tuck in the leading edge the filter fill fit nicely.

The Most Difficult QSC 1400 Amplifier Repair yet

I was tempted to call this the 1400 amplifier repair from hell.  It needed more repairs than any other amplifier that I have fixed in the past.  It started off with the usual 3K at two watt resistor being fried.  That caused one of the OP amps to have only four volts on pin eight instead of 15 volts like when it is working properly.  Simple enough, replace it.  I did not have a 3K two watt resistor so I used three 1K one watt resistors in series.

When the amplifier still did not work, I checked the 3.9 volt zener diodes, they another common part to fail.  However they were both good.  Then I noticed that the idle output of the OP amp was at three volts.  If I remove the OP amp, the positive input was still at .3 volts, that in turn would cause the OP amp to output 3 volts and that pushed the amplifier output to over 30 volts at idle.  So where was the .3 volts coming from?

First you need to know that QSC amplifiers work like no other amplifier.  The "ground" floats, the output transistors are directly mounted on the heat sink without an insulator, there is no center tap on the power transformer to be a ground.  So a ground reference is created with two matched resistors, one to +75 and one to -75 volts.  The middle of the resistors should be at zero volts.  That was where the problem was, one of the two matched resistors was open.  I had to replace both of them so they match, and I did not have 47K at one watt so I used two 100K at 1/2 watt resistors in parallel for each of the two 47K resistors.

Here is the schematic, I circled the blown parts in red.

Here is a picture of the repaired amplifier, red arrows point out the replaced parts.

Now I said this was a difficult repair, that is because there were two other repairs that I made along the way.  At some point I noticed that there was a resistor that was not properly soldered in.  When I soldered it, the amplifier went into shut down and would not power up.  The next problem turned out to be a bad connection on the heat sensor that is mounted on the heat sink.  With those two additional repairs, the amplifier was finally up and running.

I need your help getting to the top in Amazon books

   If you have read any of my books and liked them PLEASE go to Amazon and give it a positive review.  So far most of my books only have one review, and I need to have lots of positive reviews to get to the top in Amazon searches.  Most of my books are available in both printed and Kindle versions. THANKS!

Here are some of my books:
Arduino LED Projects: www.amazon.com/Arduino-L-E-D-Projects-ebook/dp/B00C4YY9DY/

Arduino LCD Projects: http://www.amazon.com/Arduino-LCD-Projects-Robert-Davis/dp/1490980709

Fringe Electronic 'Medical' Devices: http://www.amazon.com/Fringe-Electronic-Medical-Devices-Robert/dp/1491042494

Creation is a Fact!: www.amazon.com/Creation-Fact-Scientific-Historical-Evidence/dp/1491220597

The supposed upcoming worldwide solar tsunami predicted by Snowden

I looked on the "Truth or fiction" web site and cannot find anythig on this, so I thought I would give my opinion here.

IT IS PURELY FICTION!

Here is what our sun looks like now according to NASA;

I have been reading about this, but like the Y2K problem, and the Mayan calendar, I have issues with it. 

* First solar reversal happens every 11 years so this is nothing new or unusual.
* Second the impact of solar storms is totally unpredictable, most miss the earth.
* Third the greatest effect will be on things attached to long wires, like telephone and power lines, NOT on your computer or car. 

On the other hand the loss of our power grid would lead to the loss of gas for your car and gas for delivering food. As always have a six month supply of food and water on hand. Some say to have a years supply.

What they are talking about is  called the "Carrington" effect.  Back in like 1859 or something like that, a solar storm fried the telegraph wires.  By the way, these days our power grid has lots of protection, it takes direct lightning strikes and keeps on working....

All of these false "End of the World" things are to take your mind away from the REAL problem: We are at a far greater risk of a worldwide economic collapse brought on by the actions of our government and the bankers..... 

Installing my first addressable alarm system

During the last two weekends I have spent some time back up at Elim installing a new alarm system.  It is the first addressable alarm system that I have ever worked with.  The alarm company wanted all new wiring so there were lots of wires to run as well.  The specs called for strobes or horn/strobes in every room, so the alarm panel needed a booster panel to run all of those alarm devices.

I have now had a hand in replacing the 110 volt systems with 24 volt systems and then replacing the 24 volt systems with an addressable system.

While I was there the wood started arriving to fix the roof of the Tab.  The moral of that story is to never put a flat room under an angled roof.  The snow falls off the angled roof and piles up on the flat roof.  Then the snow melts but the water cannot get through the drift.  Then the water leaks down into the rooms below.