Tuesday, May 29, 2012

Fix fluorescent bulbs failures

In this post we will discuss the most issues and failures related to fluorescent bulbs and how to fix it yourself

How to fix it 
Bulb lights after a certain period of operation and then turn off the lights again

Does not light up at all

Flashing at intervals 
Bulb damage because of the amount of air leakage in it, or due to corrosion priming bulb 
Replace the bulb 
The new bulb is flashing 
The bulb is bad

Starter is bad or inappropriate

Trans is inappropriate

Bad connection
Replace the bulb

Replace the trans

Check the wires and clean it from dust 
Blackouts in both sides of the bulb

   A dark ring on each end of the bulb
End of life lamp

Wick does not radiate electrons 
Replace the bulb 
A dark ring in one end of the bulb 
The separation of the wiring base of the bulb

Disconnecting of wires connecting trans

Disconnecting in one of  bulb priming
See the wires connecting the lamp base

Check trans connections

Replace the bulb 
The new bulb flashing on short periods
Starter is inappropriate

 Trans is inappropriate

Combustion of trans

Removing the wires connecting the lamp base

High value of the voltage
 Replace the starter

Replace the trans

Replace the trans

 See the connections

 Turn off the lamp until the voltage value to be returned to the normal value
The light is not normal 
Lower the value of the voltage

 Disconnecting of the circuit wires

 The accumulation of dust on the surface of the bulb 
Turn off the lamp until voltage value to be returned to the natural value

Check the connecting wires

Clean the outer surface of the bulb and keep it dry 
Noise associated with the  operation of the bulb  
Trans type is bad

  Trans is not installed well on the bulb holder

 High temperature of the trans because the long operating period 
Replace the trans

Install the trans in a good way

Take into account that trans installed so that it is exposed to air in order not to result in high temperature and combustion of it 

Monday, May 28, 2012

Photoelectric Devices

Light Sensitive Devices :

The light-sensitive elements to respond to changes that occur on light intensity and by changing the internal resistance (ie, less than the value of its resistance to increase the intensity of light), and is called light-resistance (photosensitive resistance) .

Or generate electricity and increase the intensity of power to increase light intensity of photosensitive cells abd also called solar cells.

Photosensitive Resistance :

The value of this resistance decreases by the intensity of light falling on it's made of the photoelectric light-sensitive materials (such as cadmium sulfide) (Cds) or (Slitid cadmium) (Cdse), Although other materials such as (lead sulfide) has been used. They can also improved with other materials such as copper or chlorine, in order to improve the work of the resistance in order to adjust the correct way that they change the value of the resistance according to light intensity.

Most of the Photosensitive Resistors can afford voltage range between 100v and 200v and 300v but consumption (watt) the great ability of these elements varies between 30 million and 300 million Melli Watts.

Photosensitive Resistance has many applications in electronics, for example often used in Alert devices and automatic door mechanism where a sense of the presence or absence of light is required and the following figure shows one of the simplest applications of this element.

With the development of science electronic photoelectric element has been manufactured of silicon which is similar in terms to the transistor structure.

It's the phototransistor however it's different that transistors base is light-sensitive material controls the amount of power that passes from E to C.

It can be used in : Alarms, Automatic doors  mechanism, close the blinds in the absence of the sun or vice versa, and other devices that requires a sense of light. It is also used in television sets as a receiver for the remote control.

Transistors are characterized by the possibility of working with the invisible light such as infrared, where it can be used in alarms against thieves.

Sunday, May 27, 2012

Soldering Gun

Soldering Gun is an Adapter which lowers the voltage and raises the power, Connected to it's Secondary end copper wire (yellow copper ring) to be the soldering head.

Soldering gun  is characterized by the following :

1- Quick access to the melting temperature of the soldering material - copper - tin so it is provided with trigger pressure during the welding process where the temperature reaches about 600 degrees Celsius within a few seconds.
2- High ability up to several hundred watt and thus carry out the soldering of large wires and large pieces with the highest known efficiency.
3- Small size despite it's ability.
4- High reverberate, the lost power to be low and the adapter is cooled through the holes in the body of the device.
5- Easy to replace the soldering head which is yellow copper.

How it's working :

The following figure shows the internal structure of the soldering gun
It is a converted raise stream to up to 100 AMP in it's secondary end which closed with a soldering head which is yellow copper and zinc - with it's electrical resistance much be higher than the pure copper, which the secondary circuit made of.

Primary coil has large number of rolls and thin diameter wire
And the power which passes is low-intensity
While the secondary coil consists of few rolls (sometimes one roll)
However, with a large diameter wire to pass high voltages

While the adapter is working on a permanent basis makes great heat generated in the secondary coil and the adapter itself so it has provided with a key to run only for a period of work - as long as you are holding it - and when you left it the power is stopped.

It's advised not to be used on electronic circuits and exclusively away from the semiconductor and electronic slides.

Saturday, May 26, 2012

The different types of Adapters

Adapters are available in different shapes and sizes according to its usage, including the very small and very big types. The most important kinds are Power Adapters and Audio Adapters .

Components of the Adapters :
Adapters consists of the following main parts:

The Core: which is a piece of iron .
The Main Coil: The entrance to the adapter .
The Secondary Coil : The outlet of the adapter .

Both files, main and secondary coiles are two wires wrapped on the core and doesn't touch each other.

These are some types of Adapters that you might see :

Power Adapter

Plug Adapter

Variable Voltage Adapter

Audio Adapter

DC Adapter

Electronic Board Adapter

Adapters are used to raise or lower voltage or power in electrical circuits.
And Adapters based on the feature of Mutual Inductance .

Friday, May 25, 2012

How to check Unijunction Transistor (Ujt)

Examining this type of transistors is very easy when you follow the following steps:

1- Put the status of digital Mmeltamitr to read ohms and the resistance between Base1 and Base2 to put (+) on the first base and (-) on the second base. Then reflect the polar, probably in both cases, the resistance will be equal high.

2- Put the wire (-) on the Emitter and from wire (+) Calculate the resistance between the Emitter and Base1, and the resistance between the Emitter and Base2. Both readings will mark on high value and equal to the resistance.

3- Flip the wire (-) to the Emitter (+). And now from the wire (-) Calculate the resistance between the Emitter and Base1, and the resistance between the Emitter and Base2. Both readings will mark on small value and equal to the resistance.

Thursday, May 24, 2012

PCB Resistance Reader Application

You can use this free program to read the values ​​of resistors, carbon film and metal used in electronic circuits.

This free program gives you the ability to:

1 - Read the resistors with the four color rings
2 - Read the resistors with the five color rings
And tolerance rates widely used for both types

Color interface Changed in line with your choice of colors of resistance to be read.

Comparability : 98/2000/XP/Vista/7
Extension: EXE
Size: 320.5 KB
Download : Click Here

This is another resistance reader according to color and tolerance.

Comparability : 98/2000/XP/Vista/7
Extension: EXE
Size: 212 KB
Download : Click Here

Wednesday, May 23, 2012

Electronic components abbreviations

Here is a list of Electronic Component name abbreviations widely used in the electronics industry:

AC: Alternating Current
ADC: Analog To Digital Converter 
DAC: Digital To Analog Converter
PAM: Pulse Amplitude Modulation
RF: Radio Frequency
SW: Short Wave
CB: Citizens Band
IF: Intermediate Frequency
LF: low Frequency
STN: Signal-to-Noise
SNR: Signal –to-Noise Ratio 
LO: Local Oscillator
CCTV: Close Circuit Television
ETV: Educational TV
CMOS: Complementary MOS
FET: Field Effect Transistor
LED: Light Emitting Diode
SCR: Silicon Controlled Rectifier
DCTL: Direct Coupled: Transistor Logic 
DTL: Diode Transistor Logic
RTL: Resistor Transistor Logic
TTL: Transistor-Transistor Logic
DMM: Digital Multi Meter
DVM: Digital Voltmeter 
CRO: Cathode Ray Oscilloscope
DPDT: Double Pole Double: Throw
ADF: Automatic Direction Finder
ADP: Automatic Data Processing
AFC: Automatic Frequency Control
AGC: Automatic Gain Control
BMEWS: Ballistic Missile: Early Warning System

Tuesday, May 22, 2012

Different components with the same name

There are a lot of electronic parts that have the same name, but the shape is different and in this post I will show you some of them illustrated by their pictures .

1- Diodes

2- Leds

3- Switches

 4- Transistors

Sunday, May 20, 2012

Manufacturer Symbols on the ICs

Sometimes you might read a manufacturer symbol on an Integrated Circuits ( eg. the below picture ) , Here are some of these symbols and their illustration .

AD - Analog Device
AY - General Instrument
DM - Nantional Semiconductor
HD - Hitachi
I - Intel
MC - Motorola
MJ - Plessey
MK - Mostek
MP - Micro Power System
N - Signetics
RC - Raytheon
SL - Plessey
SN - Texas Instruments
UCN - SpragueX - Xicor
XR - Raytheon
Z - Zilog
ZN - Ferranti
uA - Texas Instruments


Electronic Symbols Part2

Here is Part 2 of the most used symbols in the Electronic Boards Designs beside it's commercial look and it's names .

Component Symbols (2)

Commercial Look
Symbol Name


Inverter (NOT)

AND (2-input)

NAND (2-input)

OR (2-input)

NOR (2-input)

Integrated Circuits (IC)

7-Segment LED Display

Loud Speaker



Measuring Instrument






Power Supply

Solar Cell


Bar Antenna

Antenna (Aerial)