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This low-cost, general-purpose electronic hearing aids works off 3V DC (2×1.5V battery). Transistor T1 and associated components form the audio signal preamplifier for the acoustic signals picked up by the condenser microphone and converted into corresponding electrical signals.
The medium-power amplifier section is wired around popular audio amplifier IC TDA2822M (not TDA2822). This IC, specially designed for portable low-power applications, is readily available in 8-pin mini DIP package. Here the IC is wired in bridge configuration to drive the 32-ohm general-purpose monophonic earphone.
The audio output of this hearing aid circuit is 10 to 15 mW and the quiescent current drain is below 1 mA. The circuit can be easily assembled on a veroboard. For easy assembling and maintenance, use an 8-pin DIP IC socket for TDA2822M.
This cable tv amplifier circuit is a rf amplifier designed to be quickly installed between two coaxial cables. Both input and output impedances are compatible with 75 Ω cables. The main amplifier si T1 transistor, T2 is working as an emitter follower. The feedback bias is determined by R3 and R4.
The total gain of this tv cable amplifier is 22dB.
Because of the high frequency limit of transistors (<= 2GHz) the tv amplifier works well up to 150 MHz. It must be housed in a metal case and the coaxial cables must de 75 Ω type. The total current consumption of this tv cable amplifier circuit is around 20mA.
Tv amplifier active components
T1, T2 = 2SC4308 or 2SC1324
Are you sick of cheapo portable headphones?
Are you sick of paying $200+ for a decent set of portable cans?
Do you like Unique Technology?
Are you DIY?
These headphones use drivers that are Orthodynamic. To sum it up, they are very similar to electrostatic and ribbon drivers in that they are planar. However, one major difference between electrostatic and orthdynamic is that Orthodynamiccan be driven from simple headphone sockets whereas ‘Stats need several hundred volts for bias. This makes them the best possible candidates for HiFi drivers in most headphones with some costing more than $550 a set. Unlike most headphone or normal drivers/woofers, this type actually has the voice coil printed onto the thin mylar diaphragm instead of attached to the back. This mylar piece is actually then suspended between two strong magnets with holes in them. When a signal is applied, the diaphragm will be charged to go back and forth with the sine wave. Since the diaphragm is flat, there is not peakiness and almost no delay due to “return”. Please see th diagram below for a better understanding.
I also repaired my $60 mushkin ventura pro with some code in mpall using windows:
I wasnt able to format or explore, when I was in linux I noticed the USB stick size was 0 and the name said Phison
I reflashed a lenovo g780 bios from a usb with this tool
Bios Boot USB Stick http://www.biosflash.com/bios-boot-usb-stick.htm
In Mac Sierra disable gatekeeper
sudo spctl --master-disable
Tinkertool and ONYX are a few good aps
Using terminal command line clear or reset Bluetooth settings. Open terminal Application > Utilities or Search from spotlight search.
Copy below like one by one and Reset bluetooth using the terminal,
sudo kextunload -b com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport
sudo kextload -b com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport
Installing Hadoop on OSX
I decided that I wanted to setup a Hadoop cluster on the Mac’s I run, this was mainly decided because of Xgrid not begin available anymore on the new version os OsX. I have setup SGE clusters before, Xgrid obviously, and Microsoft Cluster Server so I wanted to get it under my belt. This isn’t the definitive guide but it worked fairly well for me, I am still not sure of some of the concepts but that will come with practice.
The first step is to make sure you have the basics.
Command line Xcode tools and Java Developer for your version os OsX.
Lets first create a group and a user on every machine.
Create a group named ‘hadoop’ and then add an admin user ‘hadoopadmin’ to the group.
Lets do everything as hadoopadmin to make it easy.
You can download Hadoop and install it yourself but I took a shortcut and used homebrew to install it.
->brew install hadoop
This will set all your env paths in the proper hadoop config files so this is a help.
Once installed lets set the config files in hadoop.
I named my machines
hadoop01 & hadoop02 for the first two.
Configure the masters and slaves file on all machines.
Also configure /etc/hosts on all machines.
# localhost is used to configure the loopback interface
# when the system is booting. Do not change this entry.
I am using 2.4.0 so they are located in
I changed these two lines.
export JAVA_HOME=`/usr/libexec/java_home -v 1.6`
#export HADOOP_OPTS="$HADOOP_OPTS -Djava.net.preferIPv4Stack=true”
export HADOOP_OPTS="-Djava.security.krb5.realm= -Djava.security.krb5.kdc=“
This last one stopped an error I was getting upon startup.
Insert this configuration
Now lets create a few hadoop directories
-> hadoop -mkdir tmp
-> hadoop -mkdir hdfs
-> hadoop -mkdir hdfs/name
-> hadoop -mkdir hdfs/data
I enabled passwordless SSH on all machines.
ssh-keygen -t dsa -P ” -f ~/.ssh/id_dsa
cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
I found info on this at
I then formatted the name node
-> hadoop namenode -format
Then started hadoop by running
I did all of this stuff on all my machines, although some items I think do not need to be.
I have to thank
For tutorials and help getting through this.