Thursday, July 2, 2015

Arduino 50 MSPS DSO Oscilloscope with TDA8703

Last night I was testing a TDA8703 analog to digital converter and after trying 36 MHz I tried 50 MHz on a whim and it worked.  I also tried 60 MHz but the TDA8703 flaked off at that speed.

Here is a picture of the test setup.

This is what the LCD screen looks like.

Here is the video of it at 50 MSPS and 25MSPS.


Tuesday, June 30, 2015

Arduino 5MSPS Oscilloscope revisited.

I have been testing various fast analog to digital converters with the Arduino.  There are two  objectives. I want to see if I can improve the old CA3306 version by getting rid of the glitches.  I want to add a FIFO that can push past 10MSPS as that was the fastest rate achieved previously.

The first picture is of a rebuilt version of the CA3306 circuit.

Next I tried a TLC5510.  The results were a bit noisy as seen in the next picture.

A picture of the TLC5510 screen.  The noise might not be the fault of the A to D converter.

TDA8703 Analog to Digital converter being tested.  At first it did not work until I increased the power from 4.2 volts (from USB) to 5 volts via an AC adapter.






The second civil war is getting closer to reality daily!

Years ago I talked about the second civil war.  Here is one of several posts:  http://bobdavis321.blogspot.com/2011/03/more-on-upcoming-second-civil-war.html

Now in light of that, the banning of the confederate flag makes sense!  Why ban the confederate flag while allowing the swastika and the ISIS flags to be sold?  Simple, they know the second civil war is coming and they want to stop it.  Now first of all lets get our facts right.  The civil war was not just about slavery!  It is called the "confederate flag" because they were against "con" the "federate" or federal powers.  You see the federal government was usurping too much power and some states wanted out of the union.  The other army was called the "Union" army for the opposite reason, they wanted to keep the union of the states.  So, now do you see why they are banning the confederate flag?

Why are we not fighting ISIS?  It is for the same reason.  The federal government needs to keep lots of troops here in the US to "keep the peace" while it continues to usurp way too much power.  Enter "Jade Helm" a "military exercise" throughout the southern (confederate) states.  This excuse allows the federal government to flood the confederate states with troops ready to fight to keep government control of those states.

I know this sounds like a bunch of conspiracy theories but unfortunately it has become reality.

Now add the upcoming stock market crash.  As the Greece economy collapses, France, Italy and Puerto Rico are also on the verge of bankruptcy.  The 18 trillion dollar debt this country owes is only the tip of the iceberg.  Internationally there is over 160 trillion in debt.  You can keep borrowing to pay the debt and "Kick the can down the road" for only so long.  Sooner or later the debt has to be paid.  If all of the money that is printed in the world was all bought together in one pile it could not even pay a fraction of the total debt!

So again I propose a solution.  Dissolve the US and split it into smaller countries - as in the second civil war.  If the US does not exist then its debts do not exist.  In any case this massive debt is going to lead to a lot of countries into declaring bankruptcy.

Also this whole "gay marriage" thing is not just about gay marriage.  It is about legitimatizing the homosexual lifestyle.  Just as abortion made "sleeping around" more legitimate, "gay marriage" makes being gay more "legitimate".  Only less than .1% of the population have had a 'gay marriage".

Monday, June 15, 2015

2015 Chaffee NY Hamfest!

One of my favorite things to do is to go to Hamfests.  Here are some pictures from this years Chaffee NY Hamfest.

This is my table.  Does anyone want air filters for parts?

What about that antique radio.

Here are some of the other vendors.


Thursday, May 14, 2015

8x8x8 Color RGB LED Cube Project

I am finishing up the biggest project for my latest book on LED cubes.  Here are a couple of video's about the 8x8x8 color LED cube.

In this first video it was just 7x7x2 in size:


In this next video it is up to 7x7x4 in size and still growing as more LED's arrive:


It has now grown to 8x8x4 in size.

I will have to use a pad per hole soldered breadboard to proceed any further.  The 7x7x4 setup takes over 200 jumpers to connect everything.  I would buy a printed circuit board but as far as I know no one makes one that meets my standards!  The closest design I have found uses latches and lots of transistors and resistors.  My design uses nothing but 74HC595 shift registers and a ULN2803.

Here are the red, green, blue and white test pictures.




And now the schematic for one layer...

Tuesday, May 12, 2015

TDA-03211C 32 inch LCD Monitor Repair

I was at a yard sale and I asked them about a 32 inch TV.  They said it was free because the screen did not light up.  It turned out to be the same model and have the same problem that I have diagnosed before.  It was bad capacitors in the HV power supply for the backlight.

Here is a picture of the bad 10 uF at 450 volt capacitors.

I replace them with 2 or 4 uF at 400 volt paper capacitors.  There is a hole pattern already there for the larger capacitors.  This picture shows the old holes and the new holes to use.

Here is what the new capacitors look like installed on the High Voltage power supply.