Monday, February 28, 2011

Quiz Practice and Quiz Master Machine or Buzzer Lockout

Davis Computers and Electronics Proudly Presents Our Products
Everything is Hand Made right here in the USA

Quiz Machines.  We make two models of quiz machines.  My unique design only has one IC the LED's form an 8 input OR gate to trigger the latch.  Other designs can be made by request, such as models with the lights in the hand units.

Quiz Practice Machine - $250.  Designed for practicing in the car, on the go, or wherever.  It features 6 players, 3 foot wires to the hand units and battery operation.

Quiz Master Machine - $250.  Designed to be used in a church for a live contest.  It features 8 players with 3, 4, 5, and 6 foot wires to the hand units.  It can be powered by an AC adapter or by a battery.  An interlocking version is available by special request.

Friday, February 25, 2011

Google Fixes Search - They Removed Content Farms

A while back I talked about link farms or content farms, in fact I even created my own definitions. It was listed under SEO and titled 'how to get rich on the internet part 2"

Now the news is out that Google has fixed its search algorithm problems.When I read that I immediately went out and checked out some common search terms.  I tried some phrases that previously found 3 or more pages of junk before you actually found any 'meat'.  To my amazement they were all spam free!  Go Google! 

On the sad front today I got 'Binged'.  That terrible virus from the ivory palaces of Microsoft got onto my computer.  Every time I try to Open Firefox it brings up that virus.  Do they feature an uninstall for it?
I went into 'tools' options' 'manage add ons' and uninstalled the virus from Microsoft.  Someone has to put a stop to this.  They are trying to take over the world by the most corrupt and immoral methods known by mankind!

Wednesday, February 16, 2011

Dunlap Clarke Amplifier Rebuild

I am once again rebuilding this Dunlap Clark amplifier. I rebuilt it around 1990 to a four channel 200 watt per channel amplifier after teh first system fried. Then a few year I got it back with two channels fried and I just fried the last channel in my latest youtube video 'comparing coils'.
The first repair was to modify the power transformer to reduce it to 60 volts center taped from 100 volts center taped.  This involved pulling out some windings and adding some jumpers around some of the windings.
This is a picture of the heat sinks witht eh TO-3 output transistors.  I will likely use TDA7294 IC's to rebuild it so the old transistors have to go!
Out of all the transistors there were only 11 that were not totally fried.  One even had the emitter lead burnt off the transistor!
The TDA7294 circuit board finally arrived. It comes in several configurations. Four 75 watt amplifiers, two 150 watt amplifiers, one 300 watt amplifier and a combination of one 150 watt and two 75 watt amplifiers. they sell for around $30 on Ebay.  Now the problem is mounting it in the heat-sink, it will require putting in smaller capacitors and drilling holes to align with the TDA7294's.

YouTube video of amplifier accidentally being fried.

Friday, February 11, 2011

Dell Latitude D610 repair

I bought a used Dell D610 laptop a year ago and really like it. Since then I have purchased over 6 of them. Recently one of them started overheating and shutting down. Normally these laptops are a lot of work to get apart, but I figured out a quick 5 minute repair for this problem.

First remove the top cover plate by prying up on the right side and rocking it back and forth to disconnect it.

Next remove the 2 screws that hold down the keyboard. To remove the keyboard unhook the catch that is on each side of it then unplug it from the motherboard.  The second screw is above the F4 key.

Next locate the screws that hold down the processor heat sink and loosen them. They stay attached to the heat sink.

When you remove the heat sink you should be able to see if it is clogged with dust like this one. Remove the dust and then put everything back together.

Be sure to check to see if the cooling fan runs on start up. It usually shuts off until it gets hot then it turns back on again automatically.

Thursday, February 10, 2011

Silent radio Sign Part 2

The Silent Radio LED sign is proceeding along nicely so far. I have decided on using an Arduino for the processor to run it.
I have tested the power supply and column driver transistors, the are all working so far.
The biggest problem so far is that the driver transistors run really hot. That is because they are half way on with 5 volts on their base and 9 volts on their collector they have to drop the difference of 4 volts at many Ma thus producing a lot of heat. A different driver circuit would cure that by turning the drivers all the way on but that would feed 9 volts to the LED array and that might be a bit too much.

Here is an updated schematic.

The next step is to get the Arduino serial and clock to connect to the signs serial and clock to send actual data to the sign.

Wednesday, February 9, 2011

Palladium Fake anti-virus

I just had the 'palladium fake anti-virus' attack a computer.  To fix it I first restarted in safe mode and then installed Malware Bytes AntiMalware (MBAM) ran a full system scan and it removed all but 7 files.  They were all located at "C:\Documents and Settings\NetworkService\Application Data" and all of them had today's date as their creation date.  I manually deleted them, emptied the recycle bin and restarted the computer.  I also ran CCleaner and it deleted all of the temporary files.

I also had to reinstall MS Office as MS Outlook was trashed and would not run even in safe mode.

MBAM Log file:
Malwarebytes' Anti-Malware
Database version: 5721
Windows 5.1.2600 Service Pack 3
Internet Explorer 7.0.5730.13
2/9/2011 12:59:34 PM
mbam-log-2011-02-09 (12-59-34).txt
Scan type: Full scan (C:\|D:\|)
Objects scanned: 221304
Time elapsed: 28 minute(s), 0 second(s)

Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 1
Registry Data Items Infected: 0
Folders Infected: 0
Files Infected: 6

Memory Processes Infected:
(No malicious items detected)
Memory Modules Infected:
(No malicious items detected)
Registry Keys Infected:
(No malicious items detected)
Registry Values Infected:
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell (Rogue.Palladium) ->

Value: Shell -> Quarantined and deleted successfully.
Registry Data Items Infected:
(No malicious items detected)
Folders Infected:
(No malicious items detected)

Files Infected:
c:\documents and settings\networkservice\application data\guwr76D.exe (Trojan.Downloader) ->
Quarantined and deleted successfully.
c:\documents and settings\networkservice\application data\r9zgp6ak4.exe (Trojan.Downloader) ->
Quarantined and deleted successfully.
c:\documents and settings\networkservice\local settings\temporary internet files\Content.IE5\683C8M6Q\cbta[1].exe (Trojan.Downloader) ->
Quarantined and deleted successfully.
c:\documents and settings\Sue\application data\palladium.exe (Rogue.Palladium) ->
Quarantined and deleted successfully.
c:\documents and settings\Sue\local settings\Temp\_check32.bat (Malware.Trace) ->
Quarantined and deleted successfully.
c:\WINDOWS\ws386.ini (Malware.Trace) ->
Quarantined and deleted successfully.

Monday, February 7, 2011

Super thumper my latest revisions.

My super thumper has been redesigned once again. The 24 volt AC adapter took 15 seconds to charge the capacitors so I went back to using a power transformer and reduced the charging time to 5 seconds. Note the use of a plastic lid to cover the coil.

Fitting the power transformer in the smaller cabinet was tricky but here it is all fit nicely in the instrument case.

Its up for sale for $250 and I might list one on Ebay to help sell them.

Thursday, February 3, 2011

Wordpress page title tag modification for dynamic titles

This code will get the web page title and description to automatically change from a page to a category to a post. That way the blue status bar at the top of your browser will more accurately reflect what you are seeing. Also If you roll over the browsers tab the box that appears will reflect what page you are on.

Basically what is says is is this a single post? If so, show the post title. Is it a category? If so, show the category name. Otherwise show the blog description.

< title > 
< ?php if ( is_single() ) 
{ bloginfo('name'); echo " - "; 
single_post_title('', true); }
elseif ( is_category() ) { bloginfo('name'); 
echo " - "; $category = get_the_category();
echo $category[0]->cat_name; }
else { bloginfo('name'); echo " - "; 
bloginfo('description'); }
? > < /title >

< meta name="description" content="
< ?php if ( is_single() ) { 
bloginfo('name'); echo " - "; 
single_post_title('', true); }
elseif ( is_category() ) { 
bloginfo('name'); echo " - "; 
$category = get_the_category();
echo $category[0]->cat_name; }
else { bloginfo('name'); echo " - "; 
bloginfo('description'); }
? > / >